Below are articles and press release with mention of phytoremediation:
1.
Assessing the correlation between anaerobic toluene degradation activity and bssA concentrations in hydrocarbon-contaminated aquifer material.
Kazy SK, Monier AL, Alvarez PJ. Department of Civil and Environmental Engineering, Rice University, MS 317; 6100 Main Street, Houston, TX, 77005, USA. The assessment of biodegradation activity in contaminated aquifers is critical to demonstrate the performance of bioremediation and natural attenuation and to parameterize models of contaminant plume dynamics. Real time quantitative PCR (qPCR) was used to target the catabolic bssA gene (coding for benzylsuccinate synthase) and a 16S rDNA phylogenetic gene (for total Bacteria) as potential biomarkers to infer on anaerobic toluene degradation rates. A significant correlation (P = 0.0003) was found over a wide range of initial toluene concentrations (1-100 mg/l) between toluene degradation rates and bssA concentrations in anaerobic microcosms prepared with aquifer material from a hydrocarbon contaminated site. In contrast, the correlation between toluene degradation activity and total Bacteria concentrations was not significant (P = 0.1125). This suggests that qPCR targeting of functional genes might offer a simple approach to estimate in situ biodegradation activity, which would enhance site investigation and modeling of natural attenuation at hydrocarbon-contaminated sites.
PMID: 20204467 [PubMed - as supplied by publisher]
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2. J Plant Physiol. 2010 Mar 1. [Epub ahead of print] Iron stabilizes thylakoid protein-pigment complexes in Indian mustard during Cd-phytoremediation as revealed by BN-SDS-PAGE and ESI-MS/MS.
Qureshi MI, D'Amici GM, Fagioni M, Rinalducci S, Zolla L. Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India. Two-dimensional BN-SDS-PAGE, ESI-MS/MS and electron microscopy (EM) were used to study the role of iron (Fe) under cadmium (Cd) stress in retention of thylakoidal multiprotein complexes (MPCs) and chloroplast ultrastructure of Indian mustard, a moderate hyperaccumulator plant. Mustard was grown hydroponically with or without iron for 17 days and then exposed to CdCl(2) for 3 days. Fe deficiency led to an increase in oxidative stress and damage to chloroplast/thylakoids accompanied by a decrease in chlorophyll content; exposure of plants to Cd further enhanced the oxidative stress and Cd accumulation (more in -Fe plants). However, the presence of iron aided plants in the suppression of oxidative stress and retention of chloroplasts and chlorophylls under Cd stress. Proteomic analyses by 2D BN-SDS-PAGE and mass spectrometry showed that Fe deficiency considerably decreased the amount of LHCII trimer, ATPase-F1 portion, cyt b6/f and RuBisCO. No or less reduction, was observed for PSI(RCI+LHCI), the PSII-core monomer, and the PSII subcomplex, while an increase in the LHCII monomer was noted. Under iron deficiency, Cd proved to be very deleterious to MPCs, except for the PSII subcomplex, the LHCII monomer and free proteins which were increased. Iron proved to be very protective in retaining almost all the complexes. MPCs showed greater susceptibility to Cd than Fe deficiency, mainly at the level of RuBisCO and cyt b6/f; an increase in the amount of the PSII subcomplex, LHCII monomer and free proteins indicates differences in the mechanisms affected by Fe deficiency and Cd stress when compared to Fe-fed plants. This study furthers our understanding of the sites actually damaged in MPCs under Fe deficiency and Cd stress. A role emerges for iron in the protection of MPCs and, hence, of the chloroplast. The present study also indicates the importance of iron for efficient phytoextraction/phytoremediation. Copyright © 2010 Elsevier GmbH. All rights reserved.
PMID: 20199821 [PubMed - as supplied by publisher]
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3. Sci Total Environ. 2010 Mar 1. [Epub ahead of print] Development of a biodegradation model for the prediction of metabolites in soil.
Dimitrov S, Nedelcheva D, Dimitrova N, Mekenyan O. Laboratory of Mathematical Chemistry, University "Prof. As. Zlatarov", 8010 Bourgas, Bulgaria. The awareness of air, soil and water pollution has driven the search for better methods for the assessment of the environmental fate of industrial chemicals. This paper is focused on the simulation of formation and transformation of metabolites in soil. The key challenges in the development of a simulator for predicting metabolic fate of chemicals in soil are the complexity of the soil compartment and incompleteness of metabolic information. Based on the collected data for metabolic fate of 183 chemicals a set of soil specific transformations were defined and used to develop a simulator for metabolism in soil. The analysis of outliers showed that the low predictability for some chemicals is due to: 1) incomplete documented metabolic pathways with missing intermediates and/or 2) reactions of condensation that are not simulated in the current version of the model. Hence, further improvement of the model requires expanding the metabolism database and further refinement of the logic of metabolic transformations used in the simulator. Copyright © 2010 Elsevier B.V. All rights reserved.
PMID: 20199798 [PubMed - as supplied by publisher]
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4. Water Res. 2010 Feb 10. [Epub ahead of print] 1,4-Dioxane biodegradation at low temperatures i n Arctic groundwater samples.
Li M, Fiorenza S, Chatham JR, Mahendra S, Alvarez PJ. Department of Civil and Environmental Engineering, Rice University, Houston, TX, USA. 1,4-Dioxane biodegradation was investigated in microcosms prepared with groundwater and soil from an impacted site in Alaska. In addition to natural attenuation conditions (i.e., no amendments), the following treatments were tested: (a) biostimulation by addition of 1-butanol (a readily available auxiliary substrate) and inorganic nutrients; and (b) bioaugmentation with Pseudonocardia dioxanivorans CB1190, a well-characterized dioxane-degrading bacterium, or with Pseudonocardia antarctica DVS 5a1, a bacterium isolated from Antarctica. Biostimulation enhanced the degradation of 50 mg L(-1) dioxane by indigenous microorganisms (about 0.01 mg dioxane d(-1) mg protein(-1)) at both 4 and 14 degrees C, with a simultaneous increase in biomass. A more pronounced enhancement was observed through bioaugmentation. Microcosms with 50 mg L(-1) initial dioxane (representing source-zone contamination) and augmented with CB1190 degraded dioxane fastest (0.16 +/- 0.04 mg dioxane d(-1) mg protein(-1)) at 14 degrees C, and the degradation rate decreased dramatically at 4 degrees C (0.021 +/- 0.007 mg dioxane d(-1) mg protein(-1)). In contrast, microcosms with DVS 5a1 degraded dioxane at similar rates at 4 degrees C and 14 degrees C (0.018 +/- 0.004 and 0.015 +/- 0.006 mg dioxane d(-1) mg protein(-1), respectively). DVS 5a1 outperformed CB1190 when the initial dioxane concentration was low (500 mug L(-1), which is representative of the leading edge of plumes). This indicates differences in competitive advantages of these two strains. Natural attenuation microcosms also showed significant degradation over 6 months when the initial dioxane concentration was 500 mug L(-1). This is the first study to report the potential for dioxane bioremediation and natural attenuation of contaminated groundwater in sensitive cold-weather ecosystems such as the Arctic. Copyright © 2010 Elsevier Ltd. All rights reserved.
PMID: 20199795 [PubMed - as supplied by publisher]
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5. Environ Sci Technol. 2010 Mar 2. [Epub ahead of print] Determination of Microbial Carbon Sourc es and Cycling during Remediation of Petroleum Hydrocarbon Impacted Soil Using Natural Abundance (14)C Analysis of PLFA.
Cowie BR, Greenberg BM, Slater GF. School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada, and Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 Canada. In a petroleum impacted land-farm soil in Sarnia, Ontario, compound-specific natural abundance radiocarbon analysis identified biodegradation by the soil microbial community as a major pathway for hydrocarbon removal in a novel remediation system. During remediation of contaminated soils by a plant growth promoting rhizobacteria enhanced phytoremediation system (PEPS), the measured Delta(14)C of phospholipid fatty acid (PLFA) biomarkers ranged from -793 per thousand to -897 per thousand, directly demonstrating microbial uptake and utilization of petroleum hydrocarbons (Delta(14)C(PHC) = -1000 per thousand). Isotopic mass balance indicated that more than 80% of microbial PLFA carbon was derived from petroleum hydrocarbons (PHC) and a maximum of 20% was obtained from metabolism of more modern carbon sources. These PLFA from the contaminated soils were the most (14)C-depleted biomarkers ever measured for an in situ environmental system, and this study demonstrated that the microbial community in this soil was subsisting primarily on petroleum hydrocarbons. In contrast, the microbial community in a nearby uncontaminated control soil maintained a more modern Delta(14)C signature than total organic carbon (Delta(14)C(PLFA) = +36 per thousand to -147 per thousand, Delta(14)C(TOC) = -148 per thousand), indicating preferential consumption of the most modern plant-derived fraction of soil organic carbon. Measurements of delta(13)C and Delta(14)C of soil CO(2) additionally demonstrated that mineralization of PHC contributed to soil CO(2) at the contaminated site. The CO(2) in the uncontaminated control soil exhibited substantially more modern Delta(14)C values, and lower soil CO(2) concentrations than the contaminated soils, suggesting increased rates of soil respiration in the contaminated soils. In combination, these results demonstrated that biodegradation in the soil microbial community was a primary pathway of petroleum hydrocarbon removal in the PEPS system. This study highlights the power of natural abundance radiocarbon for determining microbial carbon sources and identifying biodegradation pathways in complex remediation systems.
PMID: 20196610 [PubMed - as supplied by publisher]
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6. Environ Sci Technol. 2010 Mar 1. [Epub ahead of print] Biodegradation in a Partially Saturated Sand Matrix: Compounding Effects of Water Content, Bacterial Spatial Distribution, and Motility.
Dechesne A, Owsianiak M, Bazire A, Grundmann GL, Binning PJ, Smets BF. Department of Environmental Engineering, Technical University of Denmark, Miljoevej Bg 113, 2800 Kgs. Lyngby, Denmark, and Universite Lyon 1, IFR 41, CNRS, UMR5557, Ecologie Microbienne, Villeurbanne, F-69622, France. Bacterial pesticide degraders are generally heterogeneously distributed in soils, leaving soil volumes devoid of degradation potential. This is expected to have an impact on degradation rates because the degradation of pollutant molecules in such zones will be contingent either on degraders colonizing these zones or on pollutant mass transfer to neighboring zones containing degraders. In a model system, we quantified the role exerted by water on mineralization rate in the context of a heterogeneously distributed degradation potential. Alginate beads colonized by Pseudomonas putida KT2440 were inserted at prescribed locations in sand microcosms so that the initial spatial distribution of the mineralization potential was controlled. The mineralization rate was strongly affected by the matric potential (decreasing rate with decreasing matric potential) and by the initial distribution of the degraders (more aggregated distributions being associated with lower rates). The mineralization was diffusion-limited, as confirmed with a mathematical model. In wet conditions, extensive cell dispersal was observed for the flagellated wild type and, albeit to a lesser extent, for a nonflagellated mutant, partially relieving the diffusion limitation. Dry conditions, however, sustained low mineralization rates through the combined effects of low pollutant diffusivity and limited degrader dispersal.
PMID: 20192168 [PubMed - as supplied by publisher]
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7. J Contam Hydrol. 2010 Feb 6. [Epub ahead of print] Comparing the effects of various fuel alcohols on the natural attenuation of Benzene Plume s using a general substrate interaction model.
Gomez DE, Alvarez PJ. Department of Civil and Environmental Engineering, Rice University, MS-317, 6100 Main St., Houston, TX 77005, USA. The effects of five fuel alcohols (methanol, ethanol, 1-propanol, iso-butanol and n-butanol) on the natural attenuation of benzene were compared using a previously developed numerical model (General Substrate Interaction Module - GSIM) and a probabilistic sensitivity analysis. Simulations with a 30gal dissolving LNAPL (light non-aqueous phase liquid) source consisting of a range of gasoline blends (10% and 85% v:v alcohol content) suggest that all fuel alcohols can hinder the natural attenuation of benzene, due mainly to accelerated depletion of dissolved oxygen and a decrease in the specific degradation rate for benzene (due to catabolite repression and metabolic flux dilution). Simulations for blends with 10% alcohol, assuming a homogeneous sandy aquifer, inferred maximum benzene plume elongations (relative to a regular gasoline release) of 26% for ethanol, 47% for iso-butanol, 147% for methanol, 188% for 1-propanol, and 265% for n-butanol. The corresponding elongation percentages for blends with 85% alcohol were generally smaller (i.e., 25%, 54%, 135%, 163%, and 181%, respectively), reflecting a lower content of benzene in the simulated release. Benzene plume elongation and longevity were more pronounced in the presence of alcohols that biodegrade slower (e.g., propanol and n-butanol), forming longer and more persistent alcohol plumes. Conversely, ethanol and iso-butanol exhibited the lowest potential to hinder the natural attenuation of benzene, illustrating the significant effect that a small difference in chemical structure (e.g., isomers) can have on biodegradation. Overall, simulations were highly sensitive to site-specific biokinetic coefficients for alcohol degradation, which forewarns against generalizations about the level of impact of specific fuel alcohols on benzene plume dynamics. Copyright © 2010. Published by Elsevier B.V.
PMID: 20189262 [PubMed - as supplied by publisher]
8. Sci Total Environ. 2010 Feb 25. [Epub ahead of print] Sensitivity to zinc of Mediterranean woo dy species important for restoration.
Disante KB, Fuentes D, Cortina J. Dept. de Ecología - Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef" (IMEM), Universidad de Alicante, Ap 99, 03080 Alicante, Spain. Heavy metals have increased in natural woodlands and shrublands over the last several decades as a consequence of anthropogenic activities. However, our knowledge of the effects of these elements on woody species is scarce. In this study, we examined the responses of six Mediterranean woody species to increasing levels of zinc in hydroponic culture and discussed the possible implications for the restoration of contaminated sites. The species used, Pinus pinea L., Pinus pinaster Ait., Pinus halepensis Mill., Tetraclinis articulata (Vahl) Mast., Rhamnus alaternus L. and Quercus suber L. represent a climatic gradient from dry sub-humid to semi-arid conditions. Zinc concentrations in shoots ranged from 53mugg(-1) in Q. suber to 382mugg(-1) in T. articulata and were well below the levels found in roots. Zinc inhibited root elongation and root biomass and changed the root length distribution per diameter class, but the magnitude of the effects was species-specific. Only P. halepensis and Q. suber showed toxicity symptoms in aboveground parts. Species more characteristic from xeric environments (T. articulata, R. alaternus and P. halepensis) were more sensitive to zinc than species from mesic environments (Q. suber, P. pinaster and P. pinea). According to the Zn responses and bioaccumulation, Q. suber P. pinea and P. halepensis are the best candidates for field trials to test the value of woody species to restore contaminated sites. None of the species tested seemed suitable for phytoremediation. Copyright © 2010 Elsevier B.V. All rights reserved.
PMID: 20189221 [PubMed - as supplied by publisher]
9. Huan Jing Ke Xue. 2009 Dec;30(12):3718-23. [Fate of polycyclic aromatic hydrocarbons by compos ting of municipal sewage sludge and rapeseed meal]
[Article in Chinese]Pan F, Chen W, Zhang YQ, Ying CM, Liu Y, Zeng QF. School of Environmental Science & Engineering, Donghua University, Shanghai 201620, China. pf_sky@163.com The goal of these studies was to determine the fate of 16 polycyclic aromatic hydrocarbons (PAHs) during the 94 days of composting of municipal sewage sludge with rapeseed meal. The total PAHs calculated from the sum of the amounts of the 16 PAHs in the initial mixture of municipal sewage sludge was about 1.792 mg x kg(-1). Then the content of total 16 PAHs was 0.153 mg x kg(-1) at the final of composting. The level of total PAHs fell by about 91.5% (p < 0.05) at the end of composting. While the content of humic substance increased, the content of PAHs decreased in the intermediate stages (31-61 days) of composting. The treatment by composting led to a decrease of all PAHs mainly in 16-31 d, but some differences could be observed between PAHs with three or fewer aromatic rings (N=3) and those with four or more (N=4). The PAHs with N of three or fewer (except phenanthrene) exhibited a continous decrease, which the PAHs with N of four or more and phenanthrene showed increases between the 31-46 days. This indicates the high potential sorption mainly of PAHs with high molecular weight (N=4) plus phenanthrene, their tight adsorption makes them inaccessible for biodegradation. The high molecular weight PAHs showed a greater reduction of their bioavailability than low molecular weight (except benzo[b]fluoranthene).
PMID: 20187412 [PubMed - in process]
10. Huan Jing Ke Xue. 2009 Dec;30(12):3684-90. [Enzymatic activities of phenanthrene contaminated soil in wheat and clover intercropping system]
[Article in Chinese]Ma HL, Zhan XH, Zhang XB, Zhou LX. College of Resources and Environment Science, Nanjing Agricultural University, Nanjing 210095, China. hlma2008@126.com The dynamic changes of soil enzymatic activities during remediation of phenanthrene contaminated soil with clover or clover and wheat were investigated with pot experiments. Clover and wheat increased the activities of soil sucrase, polyphenol oxidase, urease and phosphatase with an increase rate in the range of 14.72%-46.52%, but inhibited the catalase activity with an inhibition rate in the range of 36.13%-94.79%. Sucrase and polyphenol oxidase reached the maximum activity values at the 14th day, and urease and phosphatase at the 21th day. Catalase got to the minimum activity value at the 7th day. In the light of these, catalase was relatively more sensitive to phenanthrene than the other enzymes, and could be employed as a key indicator to evaluate the risk of polycyclic aromatic hydrocarbon contaminated soil during remedying. Sucrase and polyphenol oxidase activities in wheat and clover intercropping system were significantly higher than in wheat or clover single-cropping system. Furthermore, there was a good negative correlation between catalase and sucrase (r = - 0.482), and polyphenol oxidase (r = -0.599), and urease (r = -0.329), and phosphatase (r = -0.297). Nonetheless, a good positive correlation existed among sucrase, polyphenol oxidase, urease and phosphatase. It is concluded that in the process of phytoremediation, soil enzymes can be employed as indicators for soil quality, it is not necessary to monitor each enzymatic activity, but to the activity of a key enzyme.
PMID: 20187407 [PubMed - in process]
11. Huan Jing Ke Xue. 2009 Dec;30(12):3676-83. [Antioxidative response of Phytolacca americana and Nicotiana tabacum to manganese stresses]
[Article in Chinese ]Zhang YX, Huang ZB, Zhang HM, Li LF, Chai TY. Department of Bioengineering, School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China. zhangyuxiu@cumtb.edu.cn Plant species capable of accumulating heavy metals are of considerable interest for phytoremediation and phytomining. The mechanism of Mn tolerance/hyperaccumulate in Phytolacca americana L. is less known. To elucidate the role of antioxidative enzyme in response to Mn, the 6-week-old seedling of Mn hyperaccumulator P. americana and non-accumulator-tobacco (Nicotiana tabacum) were exposed to half strength Hoagland solution with 1 mmol x L(-1) or 3 mmol x L(-1) MnCl2 for 4 days. The photosynthetic rate in P. americana decreased more slowly than that in tobacco, while the MDA content and electrolyte leakage in tobacco increased more rapidly than that in P. americana. For example, after exposure to 1 mmol x L(-1) Mn for 4 days, the photosynthetic rates of P. americana and tobacco in comparison to the control reduced by 13.3% and 75.5%, respectively. The MDA content and electrolyte leakage in tobacco increased by 347.3% and 120.1%, respectively, whereas Mn had no marked effect on both of it in P. americana, indicated that the oxidative damage in tobacco was more serious than that in P. americana. The activities of SOD and POD of both species increased rapidly with elevated Mn concentration and exposure time in both species, the increase of SOD activity in P. americana was higher than that in tobacco. CAT activity in tobacco declined rapidly, while the activity of CAT in P. americana was increased. The activities of SOD, POD and CAT in P. americana upon 1 mmol x L(-1) Mn exposure increased by 161.1%, 111.3% and 17.5%, respectively. The activities of SOD and POD in tobacco increased by 55.5% and 206.0%, respectively, while CAT activity decreased by 15.6%, indicating that the antioxidative enzymes in P. americana, particularly in CAT,could fully scavenge the reactive oxygen species generated by Mn toxicity. These results collectively indicate that the enzymatic antioxidation capacity is one of the important mechanisms responsible for Mn tolerance in hyperaccumulator plant species.
PMID: 20187406 [PubMed - in process]
12. Water Sci Technol. 2009;60(12):3275-84. Biological treatment of high-pH and high-concentration black liquor of cotton pulp by an immediate aerobic-anaerobic-aerobic process.
Lihong M, Furong L, Jinli W. School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China. lhmiao2002@yahoo.com.cn In this study, an immediate aerobic-anaerobic-aerobic (O/A/O) biological process was established for the treatment of black liquor of cotton pulp and was tested by both laboratory-scale batch experiment and pilot-scale continuous experiment. The effects of the hydraulic retention time (HRT) were studied, as were the alkaliphilic bacteria number, the culturing temperature and the concentration of black liquor on COD (chemical oxygen demand) removal. The total COD (COD(tot)) removal rate of the novel O/A/O process, for a black liquor with influent COD(tot) over 8,000 mg/L and pH above 12.8, was 68.7+/-4% which is similar with that of the traditional acidic-anaerobic-aerobic process (64.9+/-3%). The first aerobic stage based on alkaliphilic bacteria was the crucial part of the process, which was responsible for decreasing the influent pH from above 12 to an acceptable level for the following treatment unit. The average generation time of the alkaliphilic bacteria in the black liquor was about 36 minutes at 40 degrees C in a batch aerobic activated sludge system. The efficiency of the first aerobic stage was affected greatly by the temperature. The COD(tot) removal at 55 degrees C was much lower in comparison with the COD(tot) removal at 45 degrees C or 50 degrees C. Both the laboratory-scale batch experiments and the pilot-scale continuous experiment showed that the COD(tot) removal rate could reach about 65% for original black liquor with a pH of about 13.0 and a COD of 18,000-22,000 mg/L by the immediate O/A/O process. The first aerobic stage gave an average COD(tot) removal of 45.5% at 35 degrees C (HRT = 72 h) at a volume loading rate of 3.4 kg COD m(-3) d(-1).
PMID: 19955653 [PubMed - indexed for MEDLINE]
13. Water Sci Technol. 2009;60(12):3269-74. Pilot study of a submerged membrane bioreactor for water reclamation.
Qin JJ, Oo MH, Tao G, Kekre KA, Hashimoto T. Centre for Advanced Water Technology, PUB Consultants Pte Ltd, Singapore 608575, Singapore. QIN_Jianjun@pub.gov.sg The objective of this pilot study was to investigate the operational conditions of newly developed MBR modules for water reclamation under tropical conditions. MUDC-620A MBR modules with hollow fibre PVDF membranes from Asahi-Kasei Chemicals were used in the study. The pilot plant with capacity of 50 m(3)/d was operated continuously (24-hour) over four months on site of Ulu Pandan Water Reclamation Plant (UPWRP) in Singapore. During the study, the MLSS in membrane tank was in the range of 6,840 approximately 9,540 mg/L. Filtration operation mode of the membrane unit was 9 minutes on production and 1 minute backwash. The air scouring for the membranes was 0.18-0.30 Nm(3)/h per m(2) membrane area all of the time. Trials on different membrane fluxes were conducted to obtain the sustainable flux. The analytical results showed that COD, TOC, T-N and NH4-N of the treated water were <30 mg/L, 5-7 mg/L, <13 mg/L and <0.1 mg/L, respectively, which met the requirement of Industrial Water for reuse. TMP was in the range of 12-40 kPa and could be recovered after cleaning with 2,000 mg/L sodium hypochlorite solution. Sludge clogging could be a challenge for long-term operation with the current module design. It was concluded that it was feasible for MUDC-620A MBR to operate at a net flux of 25-29 LMH (or 0.6-0.7 m/d) for treating the municipal wastewater at UPWRP.
PMID: 19955652 [PubMed - indexed for MEDLINE]
Substances:
- Membranes, Artificial
- Sewage
14. Water Sci Technol. 2009;60(12):3253-9. Elimination of phenols, ammonia and cyanide in wash water from biomass gasification, and nitrogen recycling using planted trickling filters.
Graber A, Skvarc R, Junge-Berberović R. Institute of Natural Resource Sciences, Zurich University of Applied Sciences, Gruental, Waedenswil 8820, Switzerland. andreas.graber@zhaw.ch Trickling filters were used to treat wash water from a wood gasifier. This wash water contained toxic substances such as ammonium, cyanide, phenols, and PAH. The goal was to develop a system that degraded toxic substances, and achieved full nitrification of ammonia. A 1 kW model wood gasifier plant delivered wash water for the experiments, which was standardised to a conductivity of 3 mS/cm by dilution. Toxicity was assessed by bacterial luminescence detection, germination test with cress (Lepidium sativum), and pot plants cultivated in a hydroponic setup irrigated continuously with the wastewater. Treatment experiments were done in both planted and unplanted trickling filters. Plant yield was similar to conventional hydroponic production systems. The trickling filters achieved complete detoxification of phenol, PAH and cyanide as well as full nitrification. The specific elimination rates were 100 g m(-3) Leca d(-1) for phenols and 90 g m(-3) Leca d(-1) for ammonium in planted systems. In unplanted trickling filters circulated for 63 h, phenol concentration decreased from 83.5 mg/L to 2.5 mg/L and cyanide concentration from 0.32 mg/L to 0.02 mg/L. PAH concentrations were reduced from 3,050 microg/L to 0.89 microg/L within 68 days. The assays demonstrated the feasibility of using the technique to construct a treatment system in a partially closed circulation for gasifier wash water. The principal advantage is to convert toxic effluents from biomass gasifiers into a non-toxic, nitrogen-rich fertiliser water, enabling subsequent use in plant production and thus income generation. However, the questions of long-term performance and possible accumulation of phenols and heavy metals in the produce still have to be studied.
PMID: 19955650 [PubMed - indexed for MEDLINE]
15. Water Sci Technol. 2009;60(12):3243-51. Efficient and integrated start-up strategy for partial nitrification to nitrite treating low C/N domestic wastewater.
Guo J, Wang S, Huang H, Peng Y, Ge S, Wu C, Sun Z. School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. jianhuaguo316@yahoo.com.cn Nitrogen removal via the nitrite pathway has the potential of reducing the requirements for aeration consumption and carbon source. However, the development of an efficient and quick start-up strategy for partial nitrification to nitrite has proven difficult in the treatment of low strength wastewater. In this study, the feasibility of partial nitrification achieved by using real-time aeration duration control was not only demonstrated from the kinetic mechanism, but also was validated in three sequencing batch reactors (SBRs) fed with low C/N domestic wastewater. Nitrite accumulation could be achieved when aeration was terminated as soon as an inflexion pH point was reached (the dpH/dt became from negative to positive). The reduction or limitation of the NOB growth could be achieved through aeration duration control, due to leaving no extra time for NOB to convert the accumulated nitrite. The experimental operation results also showed that partial nitrification with nitrite accumulation ratios of over 80% was achieved successfully in these three reactors with process control. Fluorescence in situ hybridization (FISH) analysis indicated the reduction of NOB was achieved and AOB became the dominant nitrifying bacteria. Moreover, an integrated start-up strategy based on aeration duration control was proposed to quickly achieve partial nitrification to nitrite.
PMID: 19955649 [PubMed - indexed for MEDLINE]
16. Water Sci Technol. 2009;60(12):3225-32. Decolorization of anthraquinone Vat Blue 4 by the free cells of an autochthonous bacterium, Bacillus subtilis.
Olaganathan R, Patterson J. Suganthi Devadason Marine Research Institute, 44- Beach Road, Tuticorin 628001, Tamil Nadu, India. rajeeom@yahoo.com Uncontaminated soil, Vat Blue 4 contaminated soil and Vat Blue 4 effluent were screened for heterotrophic bacterial population and the bacterial density were found to be 19.3 x 10(4) Colony Forming Units (CFU)/gm, 5.5 x 10(4) CFU/gm and 1.1 x 10(4) CFU/ml respectively. Student's 't' test analysis affirmed that significant variation prevailed between the three set of 't' tests conducted (P<0.001 to 0.002). The heterotrophic bacterial population of dye contaminated soil comprised of 32.5% of Pseudomonas spp. followed by 27.5% of Bacillus spp., 15.0% of Aeromonas spp., 12.5% of Micrococcus spp. and 12.5% of Achromobacter spp. The optimum inoculums load, pH and temperature were found to be 5% (10 x 10(4) counts), 10 and 35 degrees C respectively. Free cells of B. subtilis decolorized Vat Blue 4 up to 92.30% after 24 hours of treatment. Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD(5)) and Chemical Oxygen Demand (COD) were reduced up to 50.00, 79.60 and 75.40% respectively.
PMID: 19955647 [PubMed - indexed for MEDLINE]
17. Water Sci Technol. 2009;60(12):3173-9. Similar evolution in delta 13CH4 and model-predicted relative rate of aceticlastic methanogenesis during mesophilic methanization of municipal solid wastes.
Vavilin VA, Qu X, Qu X, Mazéas L, Lemunier M, Duquennoi C, Mouchel JM, He P, Bouchez T. Cemagref, UR-HBAN, Parc de Tourvoie, Antony cedex F-92163, France. Similar evolution was obtained for the stable carbon isotope signatures delta (13)CH(4) and the model-predicted relative rate of aceticlastic methanogenesis during mesophilic methanization of municipal solid wastes. In batch incubations, the importance of aceticlastic and hydrogenotrophic methanogenesis changes in time. Initially, hydrogenotrophic methanogenesis dominated, but increasing population of Methanosarcina sp. enhances aceticlastic methanogenesis. Later, hydrogenotrophic methanogenesis intensified again. A mathematical model was developed to evaluate the relative contribution of hydrogenotrophic and aceticlastic pathways of methane generation during mesophilic batch anaerobic biodegradation of the French and the Chinese Municipal Solid Wastes (FMSW and CMSW). Taking into account molecular biology analysis reported earlier three groups of methanogens including strictly hydrogenotrophic methanogens, strictly aceticlastic methanogens (Methanosaeta sp.) and Methanosarcina sp., consuming both acetate and H(2)/H(2)CO(3) were considered in the model. The total organic and inorganic carbon concentrations, methane production volume, methane and carbon dioxide partial pressures values were used for the model calibration and validation. Methane isotopic composition (delta (13)CH(4)) evolution during the incubations was used to independently validate the model results. The model demonstrated that only the putrescible solid waste was totally converted to methane.
PMID: 19955641 [PubMed - indexed for MEDLINE]
18. Water Sci Technol. 2009;60(12):3025-33. Performance evaluation of planted and unplanted subsurface-flow constructed wetlands for the post-treatment of UASB reactor effluents.
Dornelas FL, Machado MB, von Sperling M. Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Contorno 842 - 7 andar, 30110-060, Belo Horizonte, Brazil. A system comprised by a UASB (Upflow Anaerobic Sludge Blanket) reactor followed by two horizontal subsurface-flow constructed wetlands in parallel was evaluated for the treatment of the wastewater generated in the city of Belo Horizonte, Brazil (50 inhabitants each unit). One unit was planted (Typha latifolia) and the other was unplanted. Influent and effluent samples were collected for a period of seven months. The systems were able to produce final effluents with low concentrations of organic matter and suspended solids, but showed not to be efficient in the removal of nutrients. Mean effluent concentrations for the planted and unplanted units were, respectively: BOD: 15 and 19 mg/L; COD: 42 and 64 mg/L; TSS: 3 and 5 mg/L; TN: 27 and 33 mg/L; N-NH(3): 25 and 29 mg/L; P Total: 1.2 and 1.5 mg/L. The planted wetland presented effluent concentrations and removal efficiencies significantly (Wilcoxon matched-pairs test, 5% significance level) better than the unplanted unit for most constituents. The study shows that horizontal subsurface-flow constructed wetlands can be effectively used as a post-treatment option for the effluent from UASB reactors.
PMID: 19955625 [PubMed - indexed for MEDLINE]
19. Appl Microbiol Biotechnol. 2010 Jan;85(3):763-71. Removing heavy metals from synthetic effluents using "kamikaze" Saccharomyces cerevisiae cells.
Ruta L, Paraschivescu C, Matache M, Avramescu S, Farcasanu IC. Faculty of Chemistry, University of Bucharest, Sos. Panduri 90-92, Bucharest, Romania. One key step of the bioremediation processes designed to clean up heavy metal contaminated environments is growing resistant cells that accumulate the heavy metals to ensure better removal through a combination of biosorption and continuous metabolic uptake after physical adsorption. Saccharomyces cerevisiae cells can easily act as cation biosorbents, but isolation of mutants that are both hyperaccumulating and tolerant to heavy metals proved extremely difficult. Instead, mutants that are hypersensitive to heavy metals due to increased and continuous uptake from the environment were considered, aiming to use such mutants to reduce the heavy metal content of contaminated waters. In this study, the heavy metal hypersensitive yeast strain pmr1Delta was investigated for the ability to remove Mn2+, Cu2+, Co2+, or Cd2+ from synthetic effluents. Due to increased metal accumulation, the mutant strain was more efficient than the wild-type in removing Mn2+, Cu2+, or Co2+ from synthetic effluents containing 1-2 mM cations, with a selectivity and also in removing Mn2+ and Cd2+ from synthetic effluents containing 20-50 microM cations, with a selectivity Mn2+ > Cd2+.
PMID: 19795117 [PubMed - indexed for MEDLINE]
20. Arch Environ Contam Toxicol. 2009 Nov;57(4):688-96. Epub 2009 Jun 18. Removal and accumulation of cadmium and lead by Typha latifolia exposed to single and mixed metal solutions.
Alonso-Castro AJ, Carranza-Alvarez C, Alfaro-De la Torre MC, Chávez-Guerrero L, García-De la Cruz RF. Plant Biochemistry Laboratory, Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas de la Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava # 6, Zona Universitaria, 78200, San Luis Potosí, SLP, Mexico. We investigated the effect of Cd and Pb on the growth of the aquatic macrophyte Typha latifolia; the removal from the solution and the accumulation of these elements by the plant were also studied. Thus, small plants of T. latifolia, collected from a noncontaminated site, were exposed for 10 days to Cd and Pb, in a single solution or in mixture solutions, at two concentrations of the metals (5 and 7.5 mg/L). Our results showed that T. latifolia removed effectively Cd and Pb from solutions and was able to accumulate these metals in the roots and, to a lesser extent, in the leaves. Our findings suggested a synergistic effect of Cd and Pb with respect to the toxicity to T. latifolia. Additionally, Cd diminished the Pb absorption by T. latifolia. Our results confirmed, using scanning electron microscopy, the internalization of Cd and Pb in T. latifolia.
PMID: 19536587 [PubMed - indexed for MEDLINE]
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21. Mar Biotechnol (NY). 2009 Nov-Dec;11(6):725-37. Epub 2009 Mar 14. A thermostable metal-tolerant laccase with bioremediation potential from a marine-derived fungus.
D'Souza-Ticlo D, Sharma D, Raghukumar C. Marine Biotechnology Laboratory, National Institute of Oceanography (Council of Scientific & Industrial Research), Dona Paula, Goa, 403 004, India. Laccase, an oxidoreductive enzyme, is important in bioremediation. Although marine fungi are potential sources of enzymes for industrial applications, they have been inadequately explored. The fungus MTCC 5159, isolated from decaying mangrove wood and identified as Cerrena unicolor based on the D1/D2 region of 28S and the 18S ribosomal DNA sequence, decolorized several synthetic dyes. Partially purified laccase reduced lignin content from sugarcane bagasse pulp by 36% within 24 h at 30 degrees C. Laccase was the major lignin-degrading enzyme (approximately 24,000 U L(-1)) produced when grown in low-nitrogen medium with half-strength seawater. Three laccases, Lac I, Lac II, and Lac III, of differing molecular masses were produced. Each of these, further resolved into four isozymes by anion exchange chromatography. The N-terminal amino acid sequence of the major isozyme, Lac IId showed 70-85% homology to laccases from basidiomycetes. It contained an N-linked glycan content of 17%. The optimum pH and temperature for Lac IId were 3 and 70 degrees C, respectively, the half-life at 70 degrees C being 90 min. The enzyme was most stable at pH 9 and retained >60% of its activity up to 180 min at 50 degrees C and 60 degrees C. The enzyme was not inhibited by Pb, Fe, Ni, Li, Co, and Cd at 1 mmol. This is the first report on the characterization of thermostable metal-tolerant laccase from a marine-derived fungus with a potential for industrial application.
PMID: 19283431 [PubMed - indexed for MEDLINE]
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22. Appl Biochem Biotechnol. 2010 Jan;160(1):232-43. Epub 2009 Feb 12. Genetic engineering of Caulobacter crescentus for removal of cadmium from water.
Patel J, Zhang Q, McKay RM, Vincent R, Xu Z. Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0208, USA. Hexa-histidine (6His) peptide was inserted to a permissive site of the surface layer (S-layer) protein RsaA of Caulobacter crescentus. The recombinant strain JS4022/p723-6H, expressing RsaA-6His fusion protein was examined for its ability to sequester Cd(II) from the bacterial growth medium. When mixed with 1 ppm CdCl(2), JS4022/p723-6H removed 94.3 approximately 99.9% of the Cd(II), whereas the control strain removed only 11.4 approximately 37.0%, depending on experimental conditions. The effective contact time of the cells and Cd(II) was as short as 15 min. When higher concentrations of CdCl(2) were tested, JS4022/p723-6H consistently demonstrated enhanced binding capacity over the control strain. At 15 ppm of Cd(II), each gram of JS4022/p723-6H dry cells retrieved 16.0 mg of Cd(II), comparing to 11.6 mg g(-1) achieved by the control strain. This work provides a potential cost-effective solution toward bioremediation of heavy metals from aqueous systems.
PMID: 19214794 [PubMed - indexed for MEDLINE]
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23. Appl Biochem Biotechnol. 2010 Jan;160(1):81-97. Epub 2009 Jan 23. Hexavalent chromium reduction by free and immobilized cell-free extract of Arthrobacter rhombi-RE.
Elangovan R, Philip L, Chandraraj K. Department of Civil Engineering, Indian Institute of Technology, Chennai, India. In the present study, hexavalent chromium (Cr(VI)) reduction potential of chromium reductase associated with the cell-free extracts (CFE) of Arthrobacter rhombi-RE species was evaluated. Arthrobacter rhombi-RE, an efficient Cr(VI) reducing bacterium, was enriched and isolated from a chromium-contaminated site. Chromium reductase activity of Arthrobacter rhombi-RE strain was associated with the cell-free extract and the contribution of extracellular enzymes to Cr(VI) reduction was negligible. NADH enhanced the chromium reductase activity. The enzyme activity was optimal at a pH of 5.5 and a temperature of 30 degrees C. Among the ten electron donors screened, sodium pyruvate was the most effective one followed by NADH and propionic acid. Michaelis-Menten constant, K(m), and maximum reaction rate, V(max), obtained from the Lineweaver-Burk plot were 48 microM and 4.09 nM/mg protein/min, respectively, in presence of NADH as electron donor and 170.5 microM and 4.29 nM/mg protein/min, respectively, in presence of sodium pyruvate as electron donor. Ca(2+) enhanced the enzyme activity while Hg(2+), Cd(2+), Ba(2+), and Zn(2+) inhibited the enzyme activity. Among the various immobilization matrices screened, calcium alginate beads seemed to be the most effective one. Though immobilized enzyme system was able to reduce Cr(VI), the performance was not very encouraging in continuous mode of operation.
PMID: 19165627 [PubMed - indexed for MEDLINE]
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MeSH Terms:
- Alginates/pharmacology
- Arthrobacter/cytology*
- Biodegradation, Environmental
- Bioreactors
- Cell Extracts*
- Chromium/chemistry
- Chromium/isolation & purification*
- Chromium/metabolism*
- Chromium/pharmacology
- Electron Transport
- Environmental Pollutants/chemistry
- Environmental Pollutants/isolation & purification
- Environmental Pollutants/metabolism
- Environmental Pollutants/pharmacology
- Enzymes, Immobilized/chemistry
- Enzymes, Immobilized/metabolism*
- Extracellular Space/enzymology
- Glucuronic Acid/pharmacology
- Hexuronic Acids/pharmacology
- Hydrogen-Ion Concentration
- Kinetics
- Oxidoreductases/chemistry
- Oxidoreductases/metabolism*
- Temperature
- Waste Disposal, Fluid
Substances:
- Alginates
- Cell Extracts
- Environmental Pollutants
- Enzymes, Immobilized
- Hexuronic Acids
- Glucuronic Acid
- Chromium
- alginic acid
- Oxidoreductases
Riverlink details work on Buttermilk Creek in West AshevilleAbout four years ago, RiverLink started working with the neighborhoods around West Asheville and Malvern Hills Park. Our first neighborhood project was the "Name that Creek" contest and through it we discovered the history of what now is officially Buttermilk Creek on the USGS maps. We worked with the neighborhood to give this formerly unnamed tributary of Hominy Creek the name, Buttermilk Creek. We discovered through research that in the old days when the milk company upstream cleaned their trucks at the end of the day the creek ran white, hence the name, Buttermilk Creek!
This past November, with a grant provided by the Clean Water Management Trust Fund, RiverLink started a new project along the creek at the parks to eliminate erosion, improve water quality and habitat, and capture stormwater runoff from adjacent impervious surfaces. Despite the terrible weather, we are approaching a successful completion. Thanks largely to the hardy folk from the neighborhood, local schools, UNCA students, Green Opportunities (GO), and the committed RiverLink volunteers who joined in the stalwart effort put forth by contractor Bryant Land and Development, of Burnsville, NC., and Baker Engineering who we hired to design and implement this project.
The projects are examples of natural channel design and stormwater Low Impact Development (LID). The project components, approximately 1,500 linear feet of stream work and over a half-dozen retrofitted LID stormwater practices, are intended to treat the causes (runoff and channel manipulation) and symptoms (erosion, tree loss, etc.) that have plagued the parks' riparian corridors for decades. We were determined with this project and the help of our design team to treat the causes, not just the symptoms of stream impairment which is a critical component of efforts to successfully restore impaired watersheds.
The LID practices: rain gardens, swales, biorention basins and other earthworks, will be planted with native vegetation intended to provide bioremediation (any process that uses microorganisms, fungi, green plants or their enzymes to return the natural environment altered by contaminants to its original condition) of pollutants, water uptake and transpiration, an appealing aesthetic and a high quality terrestrial habitat for birds, butterflies, bees and other creatures (even you!). If you go down to the parks, you may notice the logs and boulders installed in the creek and the creation of new "floodplain benching" adjacent to the channel itself. While coming at the expense of some nice trees, these are the critical features that will ensure the long-term sustainability of the stream restorative efforts, contribute to new aquatic habitat niches, and prevent bank and bed erosion that previously afflicted the creek. According to Karen Cragnolin, executive director of RiverLink, "The "new" parks are to be fully enjoyed, but in these first months after the plantings we are asking everyone who loves these parks to please respect the vulnerability of disturbed areas and help protect them as they become better-established over this first year of recovery for the park ecosystem."
Below are articles and press release with mention of phytoremediation:
| 1. | Assessing the correlation between anaerobic toluene degradation activity and bssA concentrations in hydrocarbon-contaminated aquifer material.Kazy SK, Monier AL, Alvarez PJ.Department of Civil and Environmental Engineering, Rice University, MS 317; 6100 Main Street, Houston, TX, 77005, USA. The assessment of biodegradation activity in contaminated aquifers is critical to demonstrate the performance of bioremediation and natural attenuation and to parameterize models of contaminant plume dynamics. Real time quantitative PCR (qPCR) was used to target the catabolic bssA gene (coding for benzylsuccinate synthase) and a 16S rDNA phylogenetic gene (for total Bacteria) as potential biomarkers to infer on anaerobic toluene degradation rates. A significant correlation (P = 0.0003) was found over a wide range of initial toluene concentrations (1-100 mg/l) between toluene degradation rates and bssA concentrations in anaerobic microcosms prepared with aquifer material from a hydrocarbon contaminated site. In contrast, the correlation between toluene degradation activity and total Bacteria concentrations was not significant (P = 0.1125). This suggests that qPCR targeting of functional genes might offer a simple approach to estimate in situ biodegradation activity, which would enhance site investigation and modeling of natural attenuation at hydrocarbon-contaminated sites. |
| PMID: 20204467 [PubMed - as supplied by publisher] | |
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| 2. | J Plant Physiol. 2010 Mar 1. [Epub ahead of print] Iron stabilizes thylakoid protein-pigment complexes in Indian mustard during Cd-phytoremediation as revealed by BN-SDS-PAGE and ESI-MS/MS.Qureshi MI, D'Amici GM, Fagioni M, Rinalducci S, Zolla L.Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India. Two-dimensional BN-SDS-PAGE, ESI-MS/MS and electron microscopy (EM) were used to study the role of iron (Fe) under cadmium (Cd) stress in retention of thylakoidal multiprotein complexes (MPCs) and chloroplast ultrastructure of Indian mustard, a moderate hyperaccumulator plant. Mustard was grown hydroponically with or without iron for 17 days and then exposed to CdCl(2) for 3 days. Fe deficiency led to an increase in oxidative stress and damage to chloroplast/thylakoids accompanied by a decrease in chlorophyll content; exposure of plants to Cd further enhanced the oxidative stress and Cd accumulation (more in -Fe plants). However, the presence of iron aided plants in the suppression of oxidative stress and retention of chloroplasts and chlorophylls under Cd stress. Proteomic analyses by 2D BN-SDS-PAGE and mass spectrometry showed that Fe deficiency considerably decreased the amount of LHCII trimer, ATPase-F1 portion, cyt b6/f and RuBisCO. No or less reduction, was observed for PSI(RCI+LHCI), the PSII-core monomer, and the PSII subcomplex, while an increase in the LHCII monomer was noted. Under iron deficiency, Cd proved to be very deleterious to MPCs, except for the PSII subcomplex, the LHCII monomer and free proteins which were increased. Iron proved to be very protective in retaining almost all the complexes. MPCs showed greater susceptibility to Cd than Fe deficiency, mainly at the level of RuBisCO and cyt b6/f; an increase in the amount of the PSII subcomplex, LHCII monomer and free proteins indicates differences in the mechanisms affected by Fe deficiency and Cd stress when compared to Fe-fed plants. This study furthers our understanding of the sites actually damaged in MPCs under Fe deficiency and Cd stress. A role emerges for iron in the protection of MPCs and, hence, of the chloroplast. The present study also indicates the importance of iron for efficient phytoextraction/phytoremediation. Copyright © 2010 Elsevier GmbH. All rights reserved. |
| PMID: 20199821 [PubMed - as supplied by publisher] | |
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| 3. | Sci Total Environ. 2010 Mar 1. [Epub ahead of print] Development of a biodegradation model for the prediction of metabolites in soil.Dimitrov S, Nedelcheva D, Dimitrova N, Mekenyan O.Laboratory of Mathematical Chemistry, University "Prof. As. Zlatarov", 8010 Bourgas, Bulgaria. The awareness of air, soil and water pollution has driven the search for better methods for the assessment of the environmental fate of industrial chemicals. This paper is focused on the simulation of formation and transformation of metabolites in soil. The key challenges in the development of a simulator for predicting metabolic fate of chemicals in soil are the complexity of the soil compartment and incompleteness of metabolic information. Based on the collected data for metabolic fate of 183 chemicals a set of soil specific transformations were defined and used to develop a simulator for metabolism in soil. The analysis of outliers showed that the low predictability for some chemicals is due to: 1) incomplete documented metabolic pathways with missing intermediates and/or 2) reactions of condensation that are not simulated in the current version of the model. Hence, further improvement of the model requires expanding the metabolism database and further refinement of the logic of metabolic transformations used in the simulator. Copyright © 2010 Elsevier B.V. All rights reserved. |
| PMID: 20199798 [PubMed - as supplied by publisher] | |
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| 4. | Water Res. 2010 Feb 10. [Epub ahead of print] 1,4-Dioxane biodegradation at low temperatures i n Arctic groundwater samples.Li M, Fiorenza S, Chatham JR, Mahendra S, Alvarez PJ.Department of Civil and Environmental Engineering, Rice University, Houston, TX, USA. 1,4-Dioxane biodegradation was investigated in microcosms prepared with groundwater and soil from an impacted site in Alaska. In addition to natural attenuation conditions (i.e., no amendments), the following treatments were tested: (a) biostimulation by addition of 1-butanol (a readily available auxiliary substrate) and inorganic nutrients; and (b) bioaugmentation with Pseudonocardia dioxanivorans CB1190, a well-characterized dioxane-degrading bacterium, or with Pseudonocardia antarctica DVS 5a1, a bacterium isolated from Antarctica. Biostimulation enhanced the degradation of 50 mg L(-1) dioxane by indigenous microorganisms (about 0.01 mg dioxane d(-1) mg protein(-1)) at both 4 and 14 degrees C, with a simultaneous increase in biomass. A more pronounced enhancement was observed through bioaugmentation. Microcosms with 50 mg L(-1) initial dioxane (representing source-zone contamination) and augmented with CB1190 degraded dioxane fastest (0.16 +/- 0.04 mg dioxane d(-1) mg protein(-1)) at 14 degrees C, and the degradation rate decreased dramatically at 4 degrees C (0.021 +/- 0.007 mg dioxane d(-1) mg protein(-1)). In contrast, microcosms with DVS 5a1 degraded dioxane at similar rates at 4 degrees C and 14 degrees C (0.018 +/- 0.004 and 0.015 +/- 0.006 mg dioxane d(-1) mg protein(-1), respectively). DVS 5a1 outperformed CB1190 when the initial dioxane concentration was low (500 mug L(-1), which is representative of the leading edge of plumes). This indicates differences in competitive advantages of these two strains. Natural attenuation microcosms also showed significant degradation over 6 months when the initial dioxane concentration was 500 mug L(-1). This is the first study to report the potential for dioxane bioremediation and natural attenuation of contaminated groundwater in sensitive cold-weather ecosystems such as the Arctic. Copyright © 2010 Elsevier Ltd. All rights reserved. |
| PMID: 20199795 [PubMed - as supplied by publisher] | |
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| 5. | Environ Sci Technol. 2010 Mar 2. [Epub ahead of print] Determination of Microbial Carbon Sourc es and Cycling during Remediation of Petroleum Hydrocarbon Impacted Soil Using Natural Abundance (14)C Analysis of PLFA.Cowie BR, Greenberg BM, Slater GF.School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1 Canada, and Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1 Canada. In a petroleum impacted land-farm soil in Sarnia, Ontario, compound-specific natural abundance radiocarbon analysis identified biodegradation by the soil microbial community as a major pathway for hydrocarbon removal in a novel remediation system. During remediation of contaminated soils by a plant growth promoting rhizobacteria enhanced phytoremediation system (PEPS), the measured Delta(14)C of phospholipid fatty acid (PLFA) biomarkers ranged from -793 per thousand to -897 per thousand, directly demonstrating microbial uptake and utilization of petroleum hydrocarbons (Delta(14)C(PHC) = -1000 per thousand). Isotopic mass balance indicated that more than 80% of microbial PLFA carbon was derived from petroleum hydrocarbons (PHC) and a maximum of 20% was obtained from metabolism of more modern carbon sources. These PLFA from the contaminated soils were the most (14)C-depleted biomarkers ever measured for an in situ environmental system, and this study demonstrated that the microbial community in this soil was subsisting primarily on petroleum hydrocarbons. In contrast, the microbial community in a nearby uncontaminated control soil maintained a more modern Delta(14)C signature than total organic carbon (Delta(14)C(PLFA) = +36 per thousand to -147 per thousand, Delta(14)C(TOC) = -148 per thousand), indicating preferential consumption of the most modern plant-derived fraction of soil organic carbon. Measurements of delta(13)C and Delta(14)C of soil CO(2) additionally demonstrated that mineralization of PHC contributed to soil CO(2) at the contaminated site. The CO(2) in the uncontaminated control soil exhibited substantially more modern Delta(14)C values, and lower soil CO(2) concentrations than the contaminated soils, suggesting increased rates of soil respiration in the contaminated soils. In combination, these results demonstrated that biodegradation in the soil microbial community was a primary pathway of petroleum hydrocarbon removal in the PEPS system. This study highlights the power of natural abundance radiocarbon for determining microbial carbon sources and identifying biodegradation pathways in complex remediation systems. |
| PMID: 20196610 [PubMed - as supplied by publisher] | |
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| 6. | Environ Sci Technol. 2010 Mar 1. [Epub ahead of print] Biodegradation in a Partially Saturated Sand Matrix: Compounding Effects of Water Content, Bacterial Spatial Distribution, and Motility.Dechesne A, Owsianiak M, Bazire A, Grundmann GL, Binning PJ, Smets BF.Department of Environmental Engineering, Technical University of Denmark, Miljoevej Bg 113, 2800 Kgs. Lyngby, Denmark, and Universite Lyon 1, IFR 41, CNRS, UMR5557, Ecologie Microbienne, Villeurbanne, F-69622, France. Bacterial pesticide degraders are generally heterogeneously distributed in soils, leaving soil volumes devoid of degradation potential. This is expected to have an impact on degradation rates because the degradation of pollutant molecules in such zones will be contingent either on degraders colonizing these zones or on pollutant mass transfer to neighboring zones containing degraders. In a model system, we quantified the role exerted by water on mineralization rate in the context of a heterogeneously distributed degradation potential. Alginate beads colonized by Pseudomonas putida KT2440 were inserted at prescribed locations in sand microcosms so that the initial spatial distribution of the mineralization potential was controlled. The mineralization rate was strongly affected by the matric potential (decreasing rate with decreasing matric potential) and by the initial distribution of the degraders (more aggregated distributions being associated with lower rates). The mineralization was diffusion-limited, as confirmed with a mathematical model. In wet conditions, extensive cell dispersal was observed for the flagellated wild type and, albeit to a lesser extent, for a nonflagellated mutant, partially relieving the diffusion limitation. Dry conditions, however, sustained low mineralization rates through the combined effects of low pollutant diffusivity and limited degrader dispersal. |
| PMID: 20192168 [PubMed - as supplied by publisher] | |
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| 7. | J Contam Hydrol. 2010 Feb 6. [Epub ahead of print] Comparing the effects of various fuel alcohols on the natural attenuation of Benzene Plume s using a general substrate interaction model.Gomez DE, Alvarez PJ.Department of Civil and Environmental Engineering, Rice University, MS-317, 6100 Main St., Houston, TX 77005, USA. The effects of five fuel alcohols (methanol, ethanol, 1-propanol, iso-butanol and n-butanol) on the natural attenuation of benzene were compared using a previously developed numerical model (General Substrate Interaction Module - GSIM) and a probabilistic sensitivity analysis. Simulations with a 30gal dissolving LNAPL (light non-aqueous phase liquid) source consisting of a range of gasoline blends (10% and 85% v:v alcohol content) suggest that all fuel alcohols can hinder the natural attenuation of benzene, due mainly to accelerated depletion of dissolved oxygen and a decrease in the specific degradation rate for benzene (due to catabolite repression and metabolic flux dilution). Simulations for blends with 10% alcohol, assuming a homogeneous sandy aquifer, inferred maximum benzene plume elongations (relative to a regular gasoline release) of 26% for ethanol, 47% for iso-butanol, 147% for methanol, 188% for 1-propanol, and 265% for n-butanol. The corresponding elongation percentages for blends with 85% alcohol were generally smaller (i.e., 25%, 54%, 135%, 163%, and 181%, respectively), reflecting a lower content of benzene in the simulated release. Benzene plume elongation and longevity were more pronounced in the presence of alcohols that biodegrade slower (e.g., propanol and n-butanol), forming longer and more persistent alcohol plumes. Conversely, ethanol and iso-butanol exhibited the lowest potential to hinder the natural attenuation of benzene, illustrating the significant effect that a small difference in chemical structure (e.g., isomers) can have on biodegradation. Overall, simulations were highly sensitive to site-specific biokinetic coefficients for alcohol degradation, which forewarns against generalizations about the level of impact of specific fuel alcohols on benzene plume dynamics. Copyright © 2010. Published by Elsevier B.V. |
| PMID: 20189262 [PubMed - as supplied by publisher] | |
| 8. | Sci Total Environ. 2010 Feb 25. [Epub ahead of print] Sensitivity to zinc of Mediterranean woo dy species important for restoration.Disante KB, Fuentes D, Cortina J.Dept. de Ecología - Instituto Multidisciplinar para el Estudio del Medio "Ramón Margalef" (IMEM), Universidad de Alicante, Ap 99, 03080 Alicante, Spain. Heavy metals have increased in natural woodlands and shrublands over the last several decades as a consequence of anthropogenic activities. However, our knowledge of the effects of these elements on woody species is scarce. In this study, we examined the responses of six Mediterranean woody species to increasing levels of zinc in hydroponic culture and discussed the possible implications for the restoration of contaminated sites. The species used, Pinus pinea L., Pinus pinaster Ait., Pinus halepensis Mill., Tetraclinis articulata (Vahl) Mast., Rhamnus alaternus L. and Quercus suber L. represent a climatic gradient from dry sub-humid to semi-arid conditions. Zinc concentrations in shoots ranged from 53mugg(-1) in Q. suber to 382mugg(-1) in T. articulata and were well below the levels found in roots. Zinc inhibited root elongation and root biomass and changed the root length distribution per diameter class, but the magnitude of the effects was species-specific. Only P. halepensis and Q. suber showed toxicity symptoms in aboveground parts. Species more characteristic from xeric environments (T. articulata, R. alaternus and P. halepensis) were more sensitive to zinc than species from mesic environments (Q. suber, P. pinaster and P. pinea). According to the Zn responses and bioaccumulation, Q. suber P. pinea and P. halepensis are the best candidates for field trials to test the value of woody species to restore contaminated sites. None of the species tested seemed suitable for phytoremediation. Copyright © 2010 Elsevier B.V. All rights reserved. |
| PMID: 20189221 [PubMed - as supplied by publisher] | |
| 9. | Huan Jing Ke Xue. 2009 Dec;30(12):3718-23. [Fate of polycyclic aromatic hydrocarbons by compos ting of municipal sewage sludge and rapeseed meal][Article in Chinese] Pan F, Chen W, Zhang YQ, Ying CM, Liu Y, Zeng QF. School of Environmental Science & Engineering, Donghua University, Shanghai 201620, China. pf_sky@163.com The goal of these studies was to determine the fate of 16 polycyclic aromatic hydrocarbons (PAHs) during the 94 days of composting of municipal sewage sludge with rapeseed meal. The total PAHs calculated from the sum of the amounts of the 16 PAHs in the initial mixture of municipal sewage sludge was about 1.792 mg x kg(-1). Then the content of total 16 PAHs was 0.153 mg x kg(-1) at the final of composting. The level of total PAHs fell by about 91.5% (p < 0.05) at the end of composting. While the content of humic substance increased, the content of PAHs decreased in the intermediate stages (31-61 days) of composting. The treatment by composting led to a decrease of all PAHs mainly in 16-31 d, but some differences could be observed between PAHs with three or fewer aromatic rings (N=3) and those with four or more (N=4). The PAHs with N of three or fewer (except phenanthrene) exhibited a continous decrease, which the PAHs with N of four or more and phenanthrene showed increases between the 31-46 days. This indicates the high potential sorption mainly of PAHs with high molecular weight (N=4) plus phenanthrene, their tight adsorption makes them inaccessible for biodegradation. The high molecular weight PAHs showed a greater reduction of their bioavailability than low molecular weight (except benzo[b]fluoranthene). |
| PMID: 20187412 [PubMed - in process] | |
| 10. | Huan Jing Ke Xue. 2009 Dec;30(12):3684-90. [Enzymatic activities of phenanthrene contaminated soil in wheat and clover intercropping system][Article in Chinese] Ma HL, Zhan XH, Zhang XB, Zhou LX. College of Resources and Environment Science, Nanjing Agricultural University, Nanjing 210095, China. hlma2008@126.com The dynamic changes of soil enzymatic activities during remediation of phenanthrene contaminated soil with clover or clover and wheat were investigated with pot experiments. Clover and wheat increased the activities of soil sucrase, polyphenol oxidase, urease and phosphatase with an increase rate in the range of 14.72%-46.52%, but inhibited the catalase activity with an inhibition rate in the range of 36.13%-94.79%. Sucrase and polyphenol oxidase reached the maximum activity values at the 14th day, and urease and phosphatase at the 21th day. Catalase got to the minimum activity value at the 7th day. In the light of these, catalase was relatively more sensitive to phenanthrene than the other enzymes, and could be employed as a key indicator to evaluate the risk of polycyclic aromatic hydrocarbon contaminated soil during remedying. Sucrase and polyphenol oxidase activities in wheat and clover intercropping system were significantly higher than in wheat or clover single-cropping system. Furthermore, there was a good negative correlation between catalase and sucrase (r = - 0.482), and polyphenol oxidase (r = -0.599), and urease (r = -0.329), and phosphatase (r = -0.297). Nonetheless, a good positive correlation existed among sucrase, polyphenol oxidase, urease and phosphatase. It is concluded that in the process of phytoremediation, soil enzymes can be employed as indicators for soil quality, it is not necessary to monitor each enzymatic activity, but to the activity of a key enzyme. |
| PMID: 20187407 [PubMed - in process] | |
| 11. | Huan Jing Ke Xue. 2009 Dec;30(12):3676-83. [Antioxidative response of Phytolacca americana and Nicotiana tabacum to manganese stresses][Article in Chinese ] Zhang YX, Huang ZB, Zhang HM, Li LF, Chai TY. Department of Bioengineering, School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China. zhangyuxiu@cumtb.edu.cn Plant species capable of accumulating heavy metals are of considerable interest for phytoremediation and phytomining. The mechanism of Mn tolerance/hyperaccumulate in Phytolacca americana L. is less known. To elucidate the role of antioxidative enzyme in response to Mn, the 6-week-old seedling of Mn hyperaccumulator P. americana and non-accumulator-tobacco (Nicotiana tabacum) were exposed to half strength Hoagland solution with 1 mmol x L(-1) or 3 mmol x L(-1) MnCl2 for 4 days. The photosynthetic rate in P. americana decreased more slowly than that in tobacco, while the MDA content and electrolyte leakage in tobacco increased more rapidly than that in P. americana. For example, after exposure to 1 mmol x L(-1) Mn for 4 days, the photosynthetic rates of P. americana and tobacco in comparison to the control reduced by 13.3% and 75.5%, respectively. The MDA content and electrolyte leakage in tobacco increased by 347.3% and 120.1%, respectively, whereas Mn had no marked effect on both of it in P. americana, indicated that the oxidative damage in tobacco was more serious than that in P. americana. The activities of SOD and POD of both species increased rapidly with elevated Mn concentration and exposure time in both species, the increase of SOD activity in P. americana was higher than that in tobacco. CAT activity in tobacco declined rapidly, while the activity of CAT in P. americana was increased. The activities of SOD, POD and CAT in P. americana upon 1 mmol x L(-1) Mn exposure increased by 161.1%, 111.3% and 17.5%, respectively. The activities of SOD and POD in tobacco increased by 55.5% and 206.0%, respectively, while CAT activity decreased by 15.6%, indicating that the antioxidative enzymes in P. americana, particularly in CAT,could fully scavenge the reactive oxygen species generated by Mn toxicity. These results collectively indicate that the enzymatic antioxidation capacity is one of the important mechanisms responsible for Mn tolerance in hyperaccumulator plant species. |
| PMID: 20187406 [PubMed - in process] | |
| 12. | Water Sci Technol. 2009;60(12):3275-84. Biological treatment of high-pH and high-concentration black liquor of cotton pulp by an immediate aerobic-anaerobic-aerobic process.Lihong M, Furong L, Jinli W.School of Biology and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China. lhmiao2002@yahoo.com.cn In this study, an immediate aerobic-anaerobic-aerobic (O/A/O) biological process was established for the treatment of black liquor of cotton pulp and was tested by both laboratory-scale batch experiment and pilot-scale continuous experiment. The effects of the hydraulic retention time (HRT) were studied, as were the alkaliphilic bacteria number, the culturing temperature and the concentration of black liquor on COD (chemical oxygen demand) removal. The total COD (COD(tot)) removal rate of the novel O/A/O process, for a black liquor with influent COD(tot) over 8,000 mg/L and pH above 12.8, was 68.7+/-4% which is similar with that of the traditional acidic-anaerobic-aerobic process (64.9+/-3%). The first aerobic stage based on alkaliphilic bacteria was the crucial part of the process, which was responsible for decreasing the influent pH from above 12 to an acceptable level for the following treatment unit. The average generation time of the alkaliphilic bacteria in the black liquor was about 36 minutes at 40 degrees C in a batch aerobic activated sludge system. The efficiency of the first aerobic stage was affected greatly by the temperature. The COD(tot) removal at 55 degrees C was much lower in comparison with the COD(tot) removal at 45 degrees C or 50 degrees C. Both the laboratory-scale batch experiments and the pilot-scale continuous experiment showed that the COD(tot) removal rate could reach about 65% for original black liquor with a pH of about 13.0 and a COD of 18,000-22,000 mg/L by the immediate O/A/O process. The first aerobic stage gave an average COD(tot) removal of 45.5% at 35 degrees C (HRT = 72 h) at a volume loading rate of 3.4 kg COD m(-3) d(-1). |
| PMID: 19955653 [PubMed - indexed for MEDLINE] | |
| 13. | Water Sci Technol. 2009;60(12):3269-74. Pilot study of a submerged membrane bioreactor for water reclamation.Qin JJ, Oo MH, Tao G, Kekre KA, Hashimoto T.Centre for Advanced Water Technology, PUB Consultants Pte Ltd, Singapore 608575, Singapore. QIN_Jianjun@pub.gov.sg The objective of this pilot study was to investigate the operational conditions of newly developed MBR modules for water reclamation under tropical conditions. MUDC-620A MBR modules with hollow fibre PVDF membranes from Asahi-Kasei Chemicals were used in the study. The pilot plant with capacity of 50 m(3)/d was operated continuously (24-hour) over four months on site of Ulu Pandan Water Reclamation Plant (UPWRP) in Singapore. During the study, the MLSS in membrane tank was in the range of 6,840 approximately 9,540 mg/L. Filtration operation mode of the membrane unit was 9 minutes on production and 1 minute backwash. The air scouring for the membranes was 0.18-0.30 Nm(3)/h per m(2) membrane area all of the time. Trials on different membrane fluxes were conducted to obtain the sustainable flux. The analytical results showed that COD, TOC, T-N and NH4-N of the treated water were <30 mg/L, 5-7 mg/L, <13 mg/L and <0.1 mg/L, respectively, which met the requirement of Industrial Water for reuse. TMP was in the range of 12-40 kPa and could be recovered after cleaning with 2,000 mg/L sodium hypochlorite solution. Sludge clogging could be a challenge for long-term operation with the current module design. It was concluded that it was feasible for MUDC-620A MBR to operate at a net flux of 25-29 LMH (or 0.6-0.7 m/d) for treating the municipal wastewater at UPWRP. |
| PMID: 19955652 [PubMed - indexed for MEDLINE] | |
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| 14. | Water Sci Technol. 2009;60(12):3253-9. Elimination of phenols, ammonia and cyanide in wash water from biomass gasification, and nitrogen recycling using planted trickling filters.Graber A, Skvarc R, Junge-Berberović R.Institute of Natural Resource Sciences, Zurich University of Applied Sciences, Gruental, Waedenswil 8820, Switzerland. andreas.graber@zhaw.ch Trickling filters were used to treat wash water from a wood gasifier. This wash water contained toxic substances such as ammonium, cyanide, phenols, and PAH. The goal was to develop a system that degraded toxic substances, and achieved full nitrification of ammonia. A 1 kW model wood gasifier plant delivered wash water for the experiments, which was standardised to a conductivity of 3 mS/cm by dilution. Toxicity was assessed by bacterial luminescence detection, germination test with cress (Lepidium sativum), and pot plants cultivated in a hydroponic setup irrigated continuously with the wastewater. Treatment experiments were done in both planted and unplanted trickling filters. Plant yield was similar to conventional hydroponic production systems. The trickling filters achieved complete detoxification of phenol, PAH and cyanide as well as full nitrification. The specific elimination rates were 100 g m(-3) Leca d(-1) for phenols and 90 g m(-3) Leca d(-1) for ammonium in planted systems. In unplanted trickling filters circulated for 63 h, phenol concentration decreased from 83.5 mg/L to 2.5 mg/L and cyanide concentration from 0.32 mg/L to 0.02 mg/L. PAH concentrations were reduced from 3,050 microg/L to 0.89 microg/L within 68 days. The assays demonstrated the feasibility of using the technique to construct a treatment system in a partially closed circulation for gasifier wash water. The principal advantage is to convert toxic effluents from biomass gasifiers into a non-toxic, nitrogen-rich fertiliser water, enabling subsequent use in plant production and thus income generation. However, the questions of long-term performance and possible accumulation of phenols and heavy metals in the produce still have to be studied. |
| PMID: 19955650 [PubMed - indexed for MEDLINE] | |
| 15. | Water Sci Technol. 2009;60(12):3243-51. Efficient and integrated start-up strategy for partial nitrification to nitrite treating low C/N domestic wastewater.Guo J, Wang S, Huang H, Peng Y, Ge S, Wu C, Sun Z.School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China. jianhuaguo316@yahoo.com.cn Nitrogen removal via the nitrite pathway has the potential of reducing the requirements for aeration consumption and carbon source. However, the development of an efficient and quick start-up strategy for partial nitrification to nitrite has proven difficult in the treatment of low strength wastewater. In this study, the feasibility of partial nitrification achieved by using real-time aeration duration control was not only demonstrated from the kinetic mechanism, but also was validated in three sequencing batch reactors (SBRs) fed with low C/N domestic wastewater. Nitrite accumulation could be achieved when aeration was terminated as soon as an inflexion pH point was reached (the dpH/dt became from negative to positive). The reduction or limitation of the NOB growth could be achieved through aeration duration control, due to leaving no extra time for NOB to convert the accumulated nitrite. The experimental operation results also showed that partial nitrification with nitrite accumulation ratios of over 80% was achieved successfully in these three reactors with process control. Fluorescence in situ hybridization (FISH) analysis indicated the reduction of NOB was achieved and AOB became the dominant nitrifying bacteria. Moreover, an integrated start-up strategy based on aeration duration control was proposed to quickly achieve partial nitrification to nitrite. |
| PMID: 19955649 [PubMed - indexed for MEDLINE] | |
| 16. | Water Sci Technol. 2009;60(12):3225-32. Decolorization of anthraquinone Vat Blue 4 by the free cells of an autochthonous bacterium, Bacillus subtilis.Olaganathan R, Patterson J.Suganthi Devadason Marine Research Institute, 44- Beach Road, Tuticorin 628001, Tamil Nadu, India. rajeeom@yahoo.com Uncontaminated soil, Vat Blue 4 contaminated soil and Vat Blue 4 effluent were screened for heterotrophic bacterial population and the bacterial density were found to be 19.3 x 10(4) Colony Forming Units (CFU)/gm, 5.5 x 10(4) CFU/gm and 1.1 x 10(4) CFU/ml respectively. Student's 't' test analysis affirmed that significant variation prevailed between the three set of 't' tests conducted (P<0.001 to 0.002). The heterotrophic bacterial population of dye contaminated soil comprised of 32.5% of Pseudomonas spp. followed by 27.5% of Bacillus spp., 15.0% of Aeromonas spp., 12.5% of Micrococcus spp. and 12.5% of Achromobacter spp. The optimum inoculums load, pH and temperature were found to be 5% (10 x 10(4) counts), 10 and 35 degrees C respectively. Free cells of B. subtilis decolorized Vat Blue 4 up to 92.30% after 24 hours of treatment. Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD(5)) and Chemical Oxygen Demand (COD) were reduced up to 50.00, 79.60 and 75.40% respectively. |
| PMID: 19955647 [PubMed - indexed for MEDLINE] | |
| 17. | Water Sci Technol. 2009;60(12):3173-9. Similar evolution in delta 13CH4 and model-predicted relative rate of aceticlastic methanogenesis during mesophilic methanization of municipal solid wastes.Vavilin VA, Qu X, Qu X, Mazéas L, Lemunier M, Duquennoi C, Mouchel JM, He P, Bouchez T.Cemagref, UR-HBAN, Parc de Tourvoie, Antony cedex F-92163, France. Similar evolution was obtained for the stable carbon isotope signatures delta (13)CH(4) and the model-predicted relative rate of aceticlastic methanogenesis during mesophilic methanization of municipal solid wastes. In batch incubations, the importance of aceticlastic and hydrogenotrophic methanogenesis changes in time. Initially, hydrogenotrophic methanogenesis dominated, but increasing population of Methanosarcina sp. enhances aceticlastic methanogenesis. Later, hydrogenotrophic methanogenesis intensified again. A mathematical model was developed to evaluate the relative contribution of hydrogenotrophic and aceticlastic pathways of methane generation during mesophilic batch anaerobic biodegradation of the French and the Chinese Municipal Solid Wastes (FMSW and CMSW). Taking into account molecular biology analysis reported earlier three groups of methanogens including strictly hydrogenotrophic methanogens, strictly aceticlastic methanogens (Methanosaeta sp.) and Methanosarcina sp., consuming both acetate and H(2)/H(2)CO(3) were considered in the model. The total organic and inorganic carbon concentrations, methane production volume, methane and carbon dioxide partial pressures values were used for the model calibration and validation. Methane isotopic composition (delta (13)CH(4)) evolution during the incubations was used to independently validate the model results. The model demonstrated that only the putrescible solid waste was totally converted to methane. |
| PMID: 19955641 [PubMed - indexed for MEDLINE] | |
| 18. | Water Sci Technol. 2009;60(12):3025-33. Performance evaluation of planted and unplanted subsurface-flow constructed wetlands for the post-treatment of UASB reactor effluents.Dornelas FL, Machado MB, von Sperling M.Department of Sanitary and Environmental Engineering, Federal University of Minas Gerais, Av. Contorno 842 - 7 andar, 30110-060, Belo Horizonte, Brazil. A system comprised by a UASB (Upflow Anaerobic Sludge Blanket) reactor followed by two horizontal subsurface-flow constructed wetlands in parallel was evaluated for the treatment of the wastewater generated in the city of Belo Horizonte, Brazil (50 inhabitants each unit). One unit was planted (Typha latifolia) and the other was unplanted. Influent and effluent samples were collected for a period of seven months. The systems were able to produce final effluents with low concentrations of organic matter and suspended solids, but showed not to be efficient in the removal of nutrients. Mean effluent concentrations for the planted and unplanted units were, respectively: BOD: 15 and 19 mg/L; COD: 42 and 64 mg/L; TSS: 3 and 5 mg/L; TN: 27 and 33 mg/L; N-NH(3): 25 and 29 mg/L; P Total: 1.2 and 1.5 mg/L. The planted wetland presented effluent concentrations and removal efficiencies significantly (Wilcoxon matched-pairs test, 5% significance level) better than the unplanted unit for most constituents. The study shows that horizontal subsurface-flow constructed wetlands can be effectively used as a post-treatment option for the effluent from UASB reactors. |
| PMID: 19955625 [PubMed - indexed for MEDLINE] | |
| 19. | Appl Microbiol Biotechnol. 2010 Jan;85(3):763-71. Removing heavy metals from synthetic effluents using "kamikaze" Saccharomyces cerevisiae cells.Ruta L, Paraschivescu C, Matache M, Avramescu S, Farcasanu IC.Faculty of Chemistry, University of Bucharest, Sos. Panduri 90-92, Bucharest, Romania. One key step of the bioremediation processes designed to clean up heavy metal contaminated environments is growing resistant cells that accumulate the heavy metals to ensure better removal through a combination of biosorption and continuous metabolic uptake after physical adsorption. Saccharomyces cerevisiae cells can easily act as cation biosorbents, but isolation of mutants that are both hyperaccumulating and tolerant to heavy metals proved extremely difficult. Instead, mutants that are hypersensitive to heavy metals due to increased and continuous uptake from the environment were considered, aiming to use such mutants to reduce the heavy metal content of contaminated waters. In this study, the heavy metal hypersensitive yeast strain pmr1Delta was investigated for the ability to remove Mn2+, Cu2+, Co2+, or Cd2+ from synthetic effluents. Due to increased metal accumulation, the mutant strain was more efficient than the wild-type in removing Mn2+, Cu2+, or Co2+ from synthetic effluents containing 1-2 mM cations, with a selectivity and also in removing Mn2+ and Cd2+ from synthetic effluents containing 20-50 microM cations, with a selectivity Mn2+ > Cd2+. |
| PMID: 19795117 [PubMed - indexed for MEDLINE] | |
| 20. | Arch Environ Contam Toxicol. 2009 Nov;57(4):688-96. Epub 2009 Jun 18. Removal and accumulation of cadmium and lead by Typha latifolia exposed to single and mixed metal solutions.Alonso-Castro AJ, Carranza-Alvarez C, Alfaro-De la Torre MC, Chávez-Guerrero L, García-De la Cruz RF.Plant Biochemistry Laboratory, Centro de Investigación y Estudios de Posgrado, Facultad de Ciencias Químicas de la Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava # 6, Zona Universitaria, 78200, San Luis Potosí, SLP, Mexico. We investigated the effect of Cd and Pb on the growth of the aquatic macrophyte Typha latifolia; the removal from the solution and the accumulation of these elements by the plant were also studied. Thus, small plants of T. latifolia, collected from a noncontaminated site, were exposed for 10 days to Cd and Pb, in a single solution or in mixture solutions, at two concentrations of the metals (5 and 7.5 mg/L). Our results showed that T. latifolia removed effectively Cd and Pb from solutions and was able to accumulate these metals in the roots and, to a lesser extent, in the leaves. Our findings suggested a synergistic effect of Cd and Pb with respect to the toxicity to T. latifolia. Additionally, Cd diminished the Pb absorption by T. latifolia. Our results confirmed, using scanning electron microscopy, the internalization of Cd and Pb in T. latifolia. |
| PMID: 19536587 [PubMed - indexed for MEDLINE] | |
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| 21. | Mar Biotechnol (NY). 2009 Nov-Dec;11(6):725-37. Epub 2009 Mar 14. A thermostable metal-tolerant laccase with bioremediation potential from a marine-derived fungus.D'Souza-Ticlo D, Sharma D, Raghukumar C.Marine Biotechnology Laboratory, National Institute of Oceanography (Council of Scientific & Industrial Research), Dona Paula, Goa, 403 004, India. Laccase, an oxidoreductive enzyme, is important in bioremediation. Although marine fungi are potential sources of enzymes for industrial applications, they have been inadequately explored. The fungus MTCC 5159, isolated from decaying mangrove wood and identified as Cerrena unicolor based on the D1/D2 region of 28S and the 18S ribosomal DNA sequence, decolorized several synthetic dyes. Partially purified laccase reduced lignin content from sugarcane bagasse pulp by 36% within 24 h at 30 degrees C. Laccase was the major lignin-degrading enzyme (approximately 24,000 U L(-1)) produced when grown in low-nitrogen medium with half-strength seawater. Three laccases, Lac I, Lac II, and Lac III, of differing molecular masses were produced. Each of these, further resolved into four isozymes by anion exchange chromatography. The N-terminal amino acid sequence of the major isozyme, Lac IId showed 70-85% homology to laccases from basidiomycetes. It contained an N-linked glycan content of 17%. The optimum pH and temperature for Lac IId were 3 and 70 degrees C, respectively, the half-life at 70 degrees C being 90 min. The enzyme was most stable at pH 9 and retained >60% of its activity up to 180 min at 50 degrees C and 60 degrees C. The enzyme was not inhibited by Pb, Fe, Ni, Li, Co, and Cd at 1 mmol. This is the first report on the characterization of thermostable metal-tolerant laccase from a marine-derived fungus with a potential for industrial application. |
| PMID: 19283431 [PubMed - indexed for MEDLINE] | |
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| 22. | Appl Biochem Biotechnol. 2010 Jan;160(1):232-43. Epub 2009 Feb 12. Genetic engineering of Caulobacter crescentus for removal of cadmium from water.Patel J, Zhang Q, McKay RM, Vincent R, Xu Z.Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0208, USA. Hexa-histidine (6His) peptide was inserted to a permissive site of the surface layer (S-layer) protein RsaA of Caulobacter crescentus. The recombinant strain JS4022/p723-6H, expressing RsaA-6His fusion protein was examined for its ability to sequester Cd(II) from the bacterial growth medium. When mixed with 1 ppm CdCl(2), JS4022/p723-6H removed 94.3 approximately 99.9% of the Cd(II), whereas the control strain removed only 11.4 approximately 37.0%, depending on experimental conditions. The effective contact time of the cells and Cd(II) was as short as 15 min. When higher concentrations of CdCl(2) were tested, JS4022/p723-6H consistently demonstrated enhanced binding capacity over the control strain. At 15 ppm of Cd(II), each gram of JS4022/p723-6H dry cells retrieved 16.0 mg of Cd(II), comparing to 11.6 mg g(-1) achieved by the control strain. This work provides a potential cost-effective solution toward bioremediation of heavy metals from aqueous systems. |
| PMID: 19214794 [PubMed - indexed for MEDLINE] | |
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| 23. | Appl Biochem Biotechnol. 2010 Jan;160(1):81-97. Epub 2009 Jan 23. Hexavalent chromium reduction by free and immobilized cell-free extract of Arthrobacter rhombi-RE.Elangovan R, Philip L, Chandraraj K.Department of Civil Engineering, Indian Institute of Technology, Chennai, India. In the present study, hexavalent chromium (Cr(VI)) reduction potential of chromium reductase associated with the cell-free extracts (CFE) of Arthrobacter rhombi-RE species was evaluated. Arthrobacter rhombi-RE, an efficient Cr(VI) reducing bacterium, was enriched and isolated from a chromium-contaminated site. Chromium reductase activity of Arthrobacter rhombi-RE strain was associated with the cell-free extract and the contribution of extracellular enzymes to Cr(VI) reduction was negligible. NADH enhanced the chromium reductase activity. The enzyme activity was optimal at a pH of 5.5 and a temperature of 30 degrees C. Among the ten electron donors screened, sodium pyruvate was the most effective one followed by NADH and propionic acid. Michaelis-Menten constant, K(m), and maximum reaction rate, V(max), obtained from the Lineweaver-Burk plot were 48 microM and 4.09 nM/mg protein/min, respectively, in presence of NADH as electron donor and 170.5 microM and 4.29 nM/mg protein/min, respectively, in presence of sodium pyruvate as electron donor. Ca(2+) enhanced the enzyme activity while Hg(2+), Cd(2+), Ba(2+), and Zn(2+) inhibited the enzyme activity. Among the various immobilization matrices screened, calcium alginate beads seemed to be the most effective one. Though immobilized enzyme system was able to reduce Cr(VI), the performance was not very encouraging in continuous mode of operation. |
| PMID: 19165627 [PubMed - indexed for MEDLINE] | |
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Riverlink details work on Buttermilk Creek in West Asheville
About four years ago, RiverLink started working with the neighborhoods around West Asheville and Malvern Hills Park. Our first neighborhood project was the "Name that Creek" contest and through it we discovered the history of what now is officially Buttermilk Creek on the USGS maps. We worked with the neighborhood to give this formerly unnamed tributary of Hominy Creek the name, Buttermilk Creek. We discovered through research that in the old days when the milk company upstream cleaned their trucks at the end of the day the creek ran white, hence the name, Buttermilk Creek!
This past November, with a grant provided by the Clean Water Management Trust Fund, RiverLink started a new project along the creek at the parks to eliminate erosion, improve water quality and habitat, and capture stormwater runoff from adjacent impervious surfaces. Despite the terrible weather, we are approaching a successful completion. Thanks largely to the hardy folk from the neighborhood, local schools, UNCA students, Green Opportunities (GO), and the committed RiverLink volunteers who joined in the stalwart effort put forth by contractor Bryant Land and Development, of Burnsville, NC., and Baker Engineering who we hired to design and implement this project.
The projects are examples of natural channel design and stormwater Low Impact Development (LID). The project components, approximately 1,500 linear feet of stream work and over a half-dozen retrofitted LID stormwater practices, are intended to treat the causes (runoff and channel manipulation) and symptoms (erosion, tree loss, etc.) that have plagued the parks' riparian corridors for decades. We were determined with this project and the help of our design team to treat the causes, not just the symptoms of stream impairment which is a critical component of efforts to successfully restore impaired watersheds.
The LID practices: rain gardens, swales, biorention basins and other earthworks, will be planted with native vegetation intended to provide bioremediation (any process that uses microorganisms, fungi, green plants or their enzymes to return the natural environment altered by contaminants to its original condition) of pollutants, water uptake and transpiration, an appealing aesthetic and a high quality terrestrial habitat for birds, butterflies, bees and other creatures (even you!). If you go down to the parks, you may notice the logs and boulders installed in the creek and the creation of new "floodplain benching" adjacent to the channel itself. While coming at the expense of some nice trees, these are the critical features that will ensure the long-term sustainability of the stream restorative efforts, contribute to new aquatic habitat niches, and prevent bank and bed erosion that previously afflicted the creek. According to Karen Cragnolin, executive director of RiverLink, "The "new" parks are to be fully enjoyed, but in these first months after the plantings we are asking everyone who loves these parks to please respect the vulnerability of disturbed areas and help protect them as they become better-established over this first year of recovery for the park ecosystem."
This past November, with a grant provided by the Clean Water Management Trust Fund, RiverLink started a new project along the creek at the parks to eliminate erosion, improve water quality and habitat, and capture stormwater runoff from adjacent impervious surfaces. Despite the terrible weather, we are approaching a successful completion. Thanks largely to the hardy folk from the neighborhood, local schools, UNCA students, Green Opportunities (GO), and the committed RiverLink volunteers who joined in the stalwart effort put forth by contractor Bryant Land and Development, of Burnsville, NC., and Baker Engineering who we hired to design and implement this project.
The projects are examples of natural channel design and stormwater Low Impact Development (LID). The project components, approximately 1,500 linear feet of stream work and over a half-dozen retrofitted LID stormwater practices, are intended to treat the causes (runoff and channel manipulation) and symptoms (erosion, tree loss, etc.) that have plagued the parks' riparian corridors for decades. We were determined with this project and the help of our design team to treat the causes, not just the symptoms of stream impairment which is a critical component of efforts to successfully restore impaired watersheds.
The LID practices: rain gardens, swales, biorention basins and other earthworks, will be planted with native vegetation intended to provide bioremediation (any process that uses microorganisms, fungi, green plants or their enzymes to return the natural environment altered by contaminants to its original condition) of pollutants, water uptake and transpiration, an appealing aesthetic and a high quality terrestrial habitat for birds, butterflies, bees and other creatures (even you!). If you go down to the parks, you may notice the logs and boulders installed in the creek and the creation of new "floodplain benching" adjacent to the channel itself. While coming at the expense of some nice trees, these are the critical features that will ensure the long-term sustainability of the stream restorative efforts, contribute to new aquatic habitat niches, and prevent bank and bed erosion that previously afflicted the creek. According to Karen Cragnolin, executive director of RiverLink, "The "new" parks are to be fully enjoyed, but in these first months after the plantings we are asking everyone who loves these parks to please respect the vulnerability of disturbed areas and help protect them as they become better-established over this first year of recovery for the park ecosystem."
http://www.shoshonenewspress.com/articles/2010/02/11/news/doc4b7438d9388aa304233094.txt
Superfund straight talk
Posted: Thursday, Feb 11, 2010 - 09:27:12 am PST
By TINA ELAYER
DEQ Mine Waste Program Specialist
Guest columnist
Phytoremediation: Phytoremediation is a way to treat contaminated soil by using plants to absorb contaminants from the soil and then harvesting the plants and hauling them to an appropriate disposal location. One of the challenges with this approach is that few plants like to absorb lead or arsenic, and when they do, they don’t absorb very much. So it can take many growing seasons to reduce lead and arsenic levels to safe levels. Also, phytoremediation is difficult to do on a large scale because the contaminated soil is extremely widespread.
For example, in the Lower Basin, over 28 square miles are contaminated; this ground would need to be seeded with lead and arsenic-loving plants. Growing these plants also may not fit with current land uses employed by landowners. For example, the plants needed for successful phytoremediation may not be a suitable replacement for grass crops such as alfalfa or grass hay, small grains, timber, or orchards.
Vitrification: Vitrification permanently traps harmful chemicals in a solid block of glass-like material. The process uses electric power to melt the soil and trap the contaminants.
Vitrification doesn’t make economic sense for large-scale applications that would be needed at this site. In-place vitrification results in a sterile, impermeable soil on which nothing can be grown and no water can infiltrate. The result would be ponded water in places where it never collected before, increased runoff into storm drains, increased runoff water temperatures, potentially more polluted storm water without the filtering effects of vegetation, and more.
At the yard-soil level, electrical currents coursing through the soil would pose a significant risk to the landowner’s water and sewer pipes, wells, fences and foundations. Vitrification is a risky choice for landowners and agencies.
Make Soil into Concrete: Concrete is a blend of cement (powdered limestone), gravel and sand. The idea behind this approach would be to use the contaminated soil to help make concrete, turning a waste into a useable product. Including soil in a concrete mix would decrease the strength of the concrete, however, and make the concrete unsuitable for most typical uses.
Fill in the Holes, a.k.a. Community Fill Policy: The “Fill in the Holes” or “Community Fill Policy” is an idea being worked on in response to requests from the community. Its purpose would be to allow moving contaminated soil from a borrow area on one person’s property to a low spot elsewhere in the Superfund site on someone else’s property.
The Institutional Controls Program (ICP) regulates contaminant migration off properties and makes sure appropriate barriers are installed over contaminated soil. As this concept is further developed, it will be discussed at meetings with local officials and to shared with the public via the Basin Commission process (Project Focus Teams).
And, now to address another recent question …
What is the life of a capped repository? How many years before it degrades and the contained waste begins leaching into the environment?
Repositories are engineered to withstand the effects of floods, earthquakes, and erosion from wind and water. After a repository is filled to capacity, it will be capped with clean soil and re-vegetated. Repositories are monitored regularly, including water quality monitoring during their construction as well as after they are completely filled and capped.
An Operations and Monitoring (O & M) Plan is created and implemented at the time of closure. The purpose of the plan is to monitor, inspect, and make repairs to avoid releases of contaminated materials back into the environment. Thus, the repositories will be inspected regularly, water quality will be monitored, and the repositories maintained as needed to prevent releases of contaminated soil and metals.
Monitoring will continue for decades after filling is complete. In sum, repositories will not be allowed to degrade, and if a problem arose, repairs would be made to prevent releases into the environment.
If you would like to be on the Bunker Hill Superfund site (Basin Bulletin) mailing list or e-mail list to get updates, contact Andrea Lindsay at lindsay.andrea@epa.gov, or call (800) 424-4372.
I would also like to report that Denna Grangaard was recently hired by DEQ as a community involvement coordinator in the Kellogg Superfund Office. She grew up in the Kellogg area and is very involved with the community.
Denna looks forward to meeting with people and their groups to provide information about the projects happening at this Superfund site. She is located in the Kellogg Superfund Project Office, 1005 West McKinley Ave., Kellogg, ID 83837. Contact her at denna.grangaard@deq.idaho.gov, or call (208) 783-5781 if you have questions about the Superfund, or if you would like to have staff from EPA/DEQ present information about projects at your next meeting.
Send questions for this column to tina.elayer@deq.idaho.gov, or write to Tina Elayer, 1005 West McKinley Ave., Kellogg, ID 83837. You can also call me at (208) 373-0563.
Posted: Thursday, Feb 11, 2010 - 09:27:12 am PST
By TINA ELAYER
DEQ Mine Waste Program Specialist
Guest columnist
In my last column I described the alternatives that have been considered to dispose of contaminated soils and then explained whether those alternatives would meet cleanup goals.
This column is a continuation of that discussion. Here I will discuss the following waste soil disposal options: phytoremediation, vitrification, making soil into concrete, and “Filling the Holes” — also known as a “Community Fill Policy (CFP).” I will also address a question that came up from the last column.Phytoremediation: Phytoremediation is a way to treat contaminated soil by using plants to absorb contaminants from the soil and then harvesting the plants and hauling them to an appropriate disposal location. One of the challenges with this approach is that few plants like to absorb lead or arsenic, and when they do, they don’t absorb very much. So it can take many growing seasons to reduce lead and arsenic levels to safe levels. Also, phytoremediation is difficult to do on a large scale because the contaminated soil is extremely widespread.
For example, in the Lower Basin, over 28 square miles are contaminated; this ground would need to be seeded with lead and arsenic-loving plants. Growing these plants also may not fit with current land uses employed by landowners. For example, the plants needed for successful phytoremediation may not be a suitable replacement for grass crops such as alfalfa or grass hay, small grains, timber, or orchards.
Vitrification doesn’t make economic sense for large-scale applications that would be needed at this site. In-place vitrification results in a sterile, impermeable soil on which nothing can be grown and no water can infiltrate. The result would be ponded water in places where it never collected before, increased runoff into storm drains, increased runoff water temperatures, potentially more polluted storm water without the filtering effects of vegetation, and more.
At the yard-soil level, electrical currents coursing through the soil would pose a significant risk to the landowner’s water and sewer pipes, wells, fences and foundations. Vitrification is a risky choice for landowners and agencies.
Make Soil into Concrete: Concrete is a blend of cement (powdered limestone), gravel and sand. The idea behind this approach would be to use the contaminated soil to help make concrete, turning a waste into a useable product. Including soil in a concrete mix would decrease the strength of the concrete, however, and make the concrete unsuitable for most typical uses.
Fill in the Holes, a.k.a. Community Fill Policy: The “Fill in the Holes” or “Community Fill Policy” is an idea being worked on in response to requests from the community. Its purpose would be to allow moving contaminated soil from a borrow area on one person’s property to a low spot elsewhere in the Superfund site on someone else’s property.
The Institutional Controls Program (ICP) regulates contaminant migration off properties and makes sure appropriate barriers are installed over contaminated soil. As this concept is further developed, it will be discussed at meetings with local officials and to shared with the public via the Basin Commission process (Project Focus Teams).
And, now to address another recent question …
What is the life of a capped repository? How many years before it degrades and the contained waste begins leaching into the environment?
Repositories are engineered to withstand the effects of floods, earthquakes, and erosion from wind and water. After a repository is filled to capacity, it will be capped with clean soil and re-vegetated. Repositories are monitored regularly, including water quality monitoring during their construction as well as after they are completely filled and capped.
An Operations and Monitoring (O & M) Plan is created and implemented at the time of closure. The purpose of the plan is to monitor, inspect, and make repairs to avoid releases of contaminated materials back into the environment. Thus, the repositories will be inspected regularly, water quality will be monitored, and the repositories maintained as needed to prevent releases of contaminated soil and metals.
Monitoring will continue for decades after filling is complete. In sum, repositories will not be allowed to degrade, and if a problem arose, repairs would be made to prevent releases into the environment.
If you would like to be on the Bunker Hill Superfund site (Basin Bulletin) mailing list or e-mail list to get updates, contact Andrea Lindsay at lindsay.andrea@epa.gov, or call (800) 424-4372.
I would also like to report that Denna Grangaard was recently hired by DEQ as a community involvement coordinator in the Kellogg Superfund Office. She grew up in the Kellogg area and is very involved with the community.
Denna looks forward to meeting with people and their groups to provide information about the projects happening at this Superfund site. She is located in the Kellogg Superfund Project Office, 1005 West McKinley Ave., Kellogg, ID 83837. Contact her at denna.grangaard@deq.idaho.gov, or call (208) 783-5781 if you have questions about the Superfund, or if you would like to have staff from EPA/DEQ present information about projects at your next meeting.
Send questions for this column to tina.elayer@deq.idaho.gov, or write to Tina Elayer, 1005 West McKinley Ave., Kellogg, ID 83837. You can also call me at (208) 373-0563.
http://www.claremontclimatereport.com/2010/02/phytoremediation-methods-and-their_11.html
Phytoremediation Methods and their Potentials
Two phytoremediation techniques are being developed to harness the ability of plants to absorb or secrete various substances (Gleba et al., 1999). The first is called phytoextraction, in which complex underground root systems extract and concentrate essential elements and compounds from soil and water. Plant roots that are hydroponically grown can also directly absorb, precipitate, and concentrate toxic metals from polluted effluents or sewage water. The second type of phytoremediation, rhizosecretion, capitalizes on the opposite effect of phytoextraction; instead of removing unwanted contaminants, rhizosecretion relies on a plants ability to make valuable compounds and deliver them into their environment. This could potentially replace solvents as a means for extracting chemicals from plants.—Patricio Ku
Gleba, D.,Nikolai, B., Ludmyla, B., Ralph, K., Alexander, P., Marina, S., Slavik, D., Sithes, L., Yuri,
Doloressa Gleba and Colleagues at Cook College and Rutgers University performed a biochemical analysis of root exudates from 120 plant species. These analyses gave evidence that roots followed an “extroverted” path in their relationship with soil, while the evolution on plant shoots primarily followed “introverted” paths by perfecting physical barriers between themselves and the environment. With this knowledge, phytoremediation techniques can be used in order to perfect and expand technology about soil remediation, drug discovery, and molecular farming.
Two phytoremediation techniques are being developed to harness the ability of plants to absorb or secrete various substances (Gleba et al., 1999). The first is called phytoextraction, in which complex underground root systems extract and concentrate essential elements and compounds from soil and water. Plant roots that are hydroponically grown can also directly absorb, precipitate, and concentrate toxic metals from polluted effluents or sewage water. The second type of phytoremediation, rhizosecretion, capitalizes on the opposite effect of phytoextraction; instead of removing unwanted contaminants, rhizosecretion relies on a plants ability to make valuable compounds and deliver them into their environment. This could potentially replace solvents as a means for extracting chemicals from plants.—Patricio Ku
Gleba, D.,Nikolai, B., Ludmyla, B., Ralph, K., Alexander, P., Marina, S., Slavik, D., Sithes, L., Yuri,
G., Ilya, R., 1999. Use of Plant Roots for Phytoremediation and Molecular Farming. Proceedings of the National Academy of Sciences 96, 5973–5977
Doloressa Gleba and Colleagues at Cook College and Rutgers University performed a biochemical analysis of root exudates from 120 plant species. These analyses gave evidence that roots followed an “extroverted” path in their relationship with soil, while the evolution on plant shoots primarily followed “introverted” paths by perfecting physical barriers between themselves and the environment. With this knowledge, phytoremediation techniques can be used in order to perfect and expand technology about soil remediation, drug discovery, and molecular farming.
When analyzing the rood exudates from the 120 plant species, a number of notable observations were made. First off, for each plant, a distinct set of compounds were exuded, giving each species a unique biochemical character. The root exudates in themselves were relatively simple mixtures, making the isolation of active molecules easier than with solvents. These exudates also did not contain any pigments or tannins, known to interfere in activity screens. Lastly, the chemical composition of root exudates is very different from that of conventional methanolic extracts of root tissue.
The future development of phytoremediation techniques lie in their development of effective and safe pharmaceuticals derived from the compilation of biologically active lead molecules secreted by the roots, and in large-scale, cost-effective manufacturing of recombinant proteins. A growing need and demand for pharmaceuticals should foster the development of these techniques. As a result, more effective utilization of biosynthetic capacity of plants based on their cheap and renewable nature will present many opportunities for scientists in the future.—Patricio Ku
HUNTSVILLE, Texas, Feb. 10 (UPI) -- The U.S. Army announced it took delivery of a wastewater treatment system that purifies within 24 hours for possible use in Haiti andAfghanistan.
Two units are on their way for U.S. troops stationed at forward operating bases in Afghanistan. Each unit can purify putrid water in about a day.
Sabin Holland, whose team at the Texas Research Institute for Environmental Studies at Sam Houston State developed the technology, said the treatment system has the potential to help decontaminate water in earthquake-stricken Haiti.
"One of the most pressing threats to public health in the aftermath of the recent earthquake is contaminated water and the lack of infrastructure to clean it up," said Holland. "This technology is an ideal application to mitigate that urgent need."
Researchers said the technology employs bioremediation using common bacteria.
"In the right combination and in the right medium, they have the capability to clean pollutedwater very quickly and very efficiently," said Holland. "It truly is a revolutionary solution."
http://www.upi.com/Science_News/Resource-Wars/2010/02/10/Water-treatment-a-possibility-for-Haiti/UPI-50431265819356/
HUNTSVILLE, Texas, Feb. 10 (UPI) -- The U.S. Army announced it took delivery of a wastewater treatment system that purifies within 24 hours for possible use in Haiti andAfghanistan.
Two units are on their way for U.S. troops stationed at forward operating bases in Afghanistan. Each unit can purify putrid water in about a day.
Sabin Holland, whose team at the Texas Research Institute for Environmental Studies at Sam Houston State developed the technology, said the treatment system has the potential to help decontaminate water in earthquake-stricken Haiti.
"One of the most pressing threats to public health in the aftermath of the recent earthquake is contaminated water and the lack of infrastructure to clean it up," said Holland. "This technology is an ideal application to mitigate that urgent need."
Researchers said the technology employs bioremediation using common bacteria.
"In the right combination and in the right medium, they have the capability to clean pollutedwater very quickly and very efficiently," said Holland. "It truly is a revolutionary solution."
The project was funded by the U.S. Defense Department.
Arctic oil finding bacteria and bioremediation by Arctic bacteria
Dr. Alexander Loy from the Department of Microbial Ecology at the University of Vienna released his teams research results that certain types of "misplaced" bacteria in Arctic waters may be used to find undiscovered underwater oil fields on January 18, 2009 at http://www.fwf.ac.at/en/public_relations/press/pv201001-en.html
The bacteria were discovered in the sediment of the Arctic Sea bed, only thrive in temperatures above 50 degrees Celsius, and exist as spores the majority of their life cycle.
The bacteria are "sulphate-reducing microorganisms." That means they use sulphate in metabolic processes to generate energy. These organisms do not require oxygen to live. A detailed explanation of sulphate reducing metabolism can be found at this web site, http://www.geobacter.org/publications/12823190.pdf
The researchers concentrated on 16S rRNA, a component of bacterial "protein factories." If bacteria have this factor they can be assumed to be related due to the rarity of the factor and the fact that this part of the bacterial RNA has changed little if any through eons of evolution.
Dr. Loy says, "The closest relatives of the thermophilic bacteria in the Arctic come from oil fields in the North Sea. Up to 96 percent of the 16S rRNA in these species is identical to that of the species found in Arctic sediment."
The result is to find new oil fields in the North Sea look for the bacterial spores.
Original article:
"A Constant Flux of Diverse Thermophilic Bacteria into the Cold Arctic Seabed" C. Hubert, A. Loy, M. Nickel, C. Arnosti, C. Baranyi, V. Brüchert, T. Ferdelman, K. Finster, F. M. Christensen, J. R. de Rezende, V. Vandieken, and B. B. Jørgensen. Science, 18th September 2009, VOL 325, doi: 10.1126/science.1174012
Dr. Alexander Loy
Department für Mikrobielle Ökologie
Dr. Alexander Loy from the Department of Microbial Ecology at the University of Vienna released his teams research results that certain types of "misplaced" bacteria in Arctic waters may be used to find undiscovered underwater oil fields on January 18, 2009 at http://www.fwf.ac.at/en/public_relations/press/pv201001-en.html
The bacteria were discovered in the sediment of the Arctic Sea bed, only thrive in temperatures above 50 degrees Celsius, and exist as spores the majority of their life cycle.
The bacteria are "sulphate-reducing microorganisms." That means they use sulphate in metabolic processes to generate energy. These organisms do not require oxygen to live. A detailed explanation of sulphate reducing metabolism can be found at this web site, http://www.geobacter.org/publications/12823190.pdf
The researchers concentrated on 16S rRNA, a component of bacterial "protein factories." If bacteria have this factor they can be assumed to be related due to the rarity of the factor and the fact that this part of the bacterial RNA has changed little if any through eons of evolution.
Dr. Loy says, "The closest relatives of the thermophilic bacteria in the Arctic come from oil fields in the North Sea. Up to 96 percent of the 16S rRNA in these species is identical to that of the species found in Arctic sediment."
The result is to find new oil fields in the North Sea look for the bacterial spores.
Original article:
"A Constant Flux of Diverse Thermophilic Bacteria into the Cold Arctic Seabed" C. Hubert, A. Loy, M. Nickel, C. Arnosti, C. Baranyi, V. Brüchert, T. Ferdelman, K. Finster, F. M. Christensen, J. R. de Rezende, V. Vandieken, and B. B. Jørgensen. Science, 18th September 2009, VOL 325, doi: 10.1126/science.1174012
Dr. Alexander Loy
Department für Mikrobielle Ökologie
The bacteria were discovered in the sediment of the Arctic Sea bed, only thrive in temperatures above 50 degrees Celsius, and exist as spores the majority of their life cycle.
The bacteria are "sulphate-reducing microorganisms." That means they use sulphate in metabolic processes to generate energy. These organisms do not require oxygen to live. A detailed explanation of sulphate reducing metabolism can be found at this web site, http://www.geobacter.org/publications/12823190.pdf
The researchers concentrated on 16S rRNA, a component of bacterial "protein factories." If bacteria have this factor they can be assumed to be related due to the rarity of the factor and the fact that this part of the bacterial RNA has changed little if any through eons of evolution.
Dr. Loy says, "The closest relatives of the thermophilic bacteria in the Arctic come from oil fields in the North Sea. Up to 96 percent of the 16S rRNA in these species is identical to that of the species found in Arctic sediment."
The result is to find new oil fields in the North Sea look for the bacterial spores.
Original article:
"A Constant Flux of Diverse Thermophilic Bacteria into the Cold Arctic Seabed" C. Hubert, A. Loy, M. Nickel, C. Arnosti, C. Baranyi, V. Brüchert, T. Ferdelman, K. Finster, F. M. Christensen, J. R. de Rezende, V. Vandieken, and B. B. Jørgensen. Science, 18th September 2009, VOL 325, doi: 10.1126/science.1174012
Dr. Alexander Loy
Department für Mikrobielle Ökologie
http://abc.az/eng/news/main/42217.html
Ecol Engineering to start planting of greenery and bioremediation work
Baku, Fineko/abc.az. Specialized subdivision of the State Oil Company of Azerbaijan (SOCAR) Ecol Engineering Services CJSC held a meeting on discussion of implementation of new projects.CJSC informed, the meeting took decision that Ecol Engineering Services jointly with production association Azneft will carry out the projects on bioremediation of oil detritus in industrial territories of oil-and-gas production departments (OGPD), in OGPD named after Z. Tagiyev (9 ha), Siyazanneft OGPD (15 ha), Abseronneft OGPD (44 ha) and Muradkhanli field (5 ha).
“The bioremediation work has already begun in the territory OGPD named after Z. Tagiyev and the work on other project will be started in February, 2010,” it was informed.
Technical issues and perspective plans were also under discussion in the meeting.
http://www.tampabay.com/news/usf-global-sustainability-conference-to-draw-leading-scientistspp/1071912
NGWA Offers Course On Low-Cost Soil And Groundwater Remediation Strategies
http://www.wateronline.com/article.mvc/NGWA-Offers-Course-On-Low-Cost-Soil-And-0001?VNETCOOKIE=NO
February 5, 2010
The National Ground Water Association is offering the three-day course, "Low-Cost Remediation Strategies for Contaminated Soil and Groundwater on February 22-24 in Dulles, Virginia.
This course provides participants with practical, technically sound guidelines on how to select the right technology for a particular site as well as how to properly design, install, and monitor that technology to meet site closure requirements.
Technologies covered include natural attenuation, enhanced bioremediation, air sparging, and phytoremediation for remediation of contaminated groundwater, bioventing for remediation of contaminated soil, and bioslurping for removal of light, non-aqueous phase liquids.
In this course, participants will:
Be provided with a balance of theory and application
Develop expertise on evaluating the significance of natural attenuation processes at groundwater-contaminated sites
Discover how to effectively analyze data to allow quantification of rates of contaminant transport and attenuation
Acquire the necessary theoretical background and skills to design and implement low-cost remediation systems
Learn "keep it simple" design and operation guidelines
Receive practical information on how to evaluate individual sites for technology applicability, perform streamlined pilot tests to confirm applicability and obtain critical design criteria, and implement expanded or full-scale remediation systems.
It is assumed in this intermediate-level course that participants have some experience in remediation system design. The course is suited to:
Site owners
Remediation engineers
Environmental consultants
Regulatory personnel
University researchers
Graduate students.
The course instructors are:
Patrick E. Haas, M.S., president and principal scientist at P.E. Haas & Associates LLC. Haas has hands-on experience collecting, analyzing, and evaluating groundwater natural attenuation geochemical parameters, passive diffusion sampler data, soil gas data, vertical profiling data, and performance monitoring data for a wide variety of remediation technologies. His experience includes start-to-site-closure involvement in the project management, design, installation, operation, and maintenance of bioventing systems, soil vapor extraction systems, conventional and vacuum-enhanced LNAPL free product recovery systems, dual phase extraction systems, and air and gas sparging systems.
Todd H. Wiedemeier, PG, president of T.H. Wiedemeier & Associates LLC. Wiedemeier has more than 14 years of experience in remediation and has conducted natural attenuation and bioremediation feasibility studies at more than 100 sites contaminated with fuel hydrocarbons, MTBE, and chlorinated solvents. Wiedemeier is the author of more than 100 publications on remediation, including the widely used Air Force Center for Environmental Excellence document titled Technical Protocol for Implementing Intrinsic Remediation with Long-Term Monitoring for Natural Attenuation of Fuel Hydrocarbons Dissolved in Groundwater, and the U.S. EPA document titled Technical Protocol for Evaluating the Natural Attenuation of Chlorinated Solvents Dissolved in Groundwater.
To learn more about this course, as well as the many other NGWA educational programs, click on the "Events/Education" menu tab above or call 800 551.7379 (614 898.7791).
About NGWA
NGWA, a nonprofit organization comprised of more than 13,000 U.S. and international groundwater professionals—contractors, equipment manufacturers, suppliers, scientists, and engineers—is dedicated to advancing groundwater knowledge. NGWA's vision is to be the leading groundwater association that advocates the responsible development, management, and use of water.
SOURCE: National Ground Water Association
Plant of the week: Tobacco Tree
Poisonous plant imported by the conquistadores
Name: Tobacco Tree (Nicotiana glaucaa)
Otherwise known as: Wild Tobacco, Maria Juana, Doctor’s Tree
Habitat: An evergreen shrub member of the Solanaceae family growing in pasture or wasteland in South and southern North America but now naturalised throughout the Mediterranean region.
The plant has a delicate stem system with a smooth, shiny grey/green bark, spear-shaped leaves and tubular yellow flowers. All parts of the plant are poisonous.
What does it do: It seems that the Tobacco Tree was brought to Europe by conquistadores that had observed the Maya and other natives smoking leaves from the plant in their religious ceremonies, however, they must have missed an essential ingredient, as smoking the dried leaf can kill you. Nicotiana glauca contains the alkaloid anabasine, one of those toxins that is so difficult to detect that there will be no sign of it in a standard autopsy and requires liquid chromatography to reveal its presence.
Anabasine is responsible for producing congenital defects in grazing and browsing animals; cows, sheep and goats, that consume the leaf or flower will abort or produce progeny with cleft palates.
During the sixties, a number of students in California, led to believe in the hallucinogenic nature of Nicotiana glauca, died as a result of smoking dried leaves: it seems that the Maya smoked the leaves mixed with crushed sea-shells which may have reduced the potency of the alkaloid.
In Europe the plant has quite a history as a folk medicine being used in poultice form to treat swollen lymph glands, rheumatic swellings and to draw off pus from scrofulous boils.
There is a great deal of modern research in phytoremediation (storage of toxins in plants) surrounding this plant, not least its ability to leech heavy metals from polluted areas. The Israelis use it in the Negev which has suffered considerable contamination in recent years. Along with Opuntia (Prickly pear), it is being examined as a cheap source of ethanol in barren and poverty stricken areas.
In Cyprus the plant is very common and known as ‘yiatros’, which translates as doctor; they use it as an astringent and a cure for cystitis.
