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https://www.readbyqxmd.com/read/27909745/dechlorination-of-three-tetrachlorobenzene-isomers-by-contaminated-harbor-sludge-derived-enrichment-cultures-follows-thermodynamically-favorable-reactions
#1
Yue Lu, Javier Ramiro-Garcia, Pieter Vandermeeren, Steffi Herrmann, Danuta Cichocka, Dirk Springael, Siavash Atashgahi, Hauke Smidt
Dechlorination patterns of three tetrachlorobenzene isomers, 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-TeCB, were studied in anoxic microcosms derived from contaminated harbor sludge. The removal of doubly, singly, and un-flanked chlorine atoms was noted in 1,2,3,4- and 1,2,3,5-TeCB fed microcosms, whereas only singly flanked chlorine was removed in 1,2,4,5-TeCB microcosms. The thermodynamically more favorable reactions were selectively followed by the enriched cultures with di- and/or mono-chlorobenzene as the main end products of the reductive dechlorination of all three isomers...
December 1, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27903429/polyhydroxyalkanoate-as-a-slow-release-carbon-source-for-in-situ-bioremediation-of-contaminated-aquifers-from-laboratory-investigation-to-pilot-scale-testing-in-the-field
#2
Lucia Pierro, Bruna Matturro, Simona Rossetti, Marco Sagliaschi, Salvatore Sucato, Eduard Alesi, Ernst Bartsch, Firoozeh Arjmand, Marco Petrangeli Papini
A pilot-scale study aiming to evaluate the potential use of poly-3-hydroxy-butyrate (PHB) as an electron donor source for in situ bioremediation of chlorinated hydrocarbons in groundwater was conducted. Compared with commercially available electron donors, PHB offers a restricted fermentation pathway (i.e., through acetic acid and molecular hydrogen) by avoiding the formation of any residual carbon that could potentially spoil groundwater quality. The pilot study was carried out at an industrial site in Italy, heavily contaminated by different chlorinated aliphatic hydrocarbons (CAHs)...
November 27, 2016: New Biotechnology
https://www.readbyqxmd.com/read/27898054/refined-experimental-annotation-reveals-conserved-corrinoid-autotrophy-in-chloroform-respiring-dehalobacter-isolates
#3
Po-Hsiang Wang, Shuiquan Tang, Kayla Nemr, Robert Flick, Jun Yan, Radhakrishnan Mahadevan, Alexander F Yakunin, Frank E Löffler, Elizabeth A Edwards
Two novel chlorinated alkane-respiring Dehalobacter restrictus strains CF and DCA were isolated from the same enrichment culture, ACT-3, and characterized. The closed genomes of these highly similar sister strains were previously assembled from metagenomic sequence data and annotated. The isolation of the strains enabled experimental verification of predicted annotations, particularly focusing on irregularities or predicted gaps in central metabolic pathways and cofactor biosynthesis. Similar to D. restrictus strain PER-K23, strains CF and DCA require arginine, histidine and threonine for growth, although the corresponding biosynthesis pathways are predicted to be functional...
November 29, 2016: ISME Journal
https://www.readbyqxmd.com/read/27894722/impact-of-bio-palladium-nanoparticles-bio-pd-nps-on-the-activity-and-structure-of-a-marine-microbial-community
#4
Andrea Nuzzo, Baharak Hosseinkhani, Nico Boon, Giulio Zanaroli, Fabio Fava
Biogenic palladium nanoparticles (bio-Pd NPs) represent a promising catalyst for organohalide remediation in water and sediments. However, the available information regarding their possible impact in case of release into the environment, particularly on the environmental microbiota, is limited. In this study the toxicity of bio-Pd NPs on the model marine bacterium V. fischeri was assessed. The impacts of different concentrations of bio-Pd NPs on the respiratory metabolisms (i.e. organohalide respiration, sulfate reduction and methanogenesis) and the structure of a PCB-dechlorinating microbial community enriched form a marine sediment were also investigated in microcosms mimicking the actual sampling site conditions...
January 2017: Environmental Pollution
https://www.readbyqxmd.com/read/27892815/monitoring-trihalomethanes-and-nitrogenous-disinfection-by-products-in-blending-desalinated-waters-using-solid%C3%A2-phase-microextraction-and-gas-chromatography
#5
Providencia González-Hernández, Manuel Hernández-Padrón, Verónica Pino, Ana M Afonso, Juan H Ayala
A simple and efficient method has been developed for the extraction and determination of sixteen common volatile halogenated disinfection by-products (DBPs) in blending desalinated waters, using headspace solid-phase microextraction and gas chromatography with flame-ionization detection (HS-SPME/GC-FID). The DBPs determined included 4 trihalomethanes, 6 haloacetonitriles and 6 halonitromethanes. After the optimization using factorial designs of the HS-SPME parameters (optimum: carboxen/polydimethylsiloxane (CAR/PDMS) fiber, extraction time of 60 min at 30 °C, pH 7, addition of 40% (w/v) of sodium chloride, and desorption time of 2 min at 250 °C), quantification limits ranged from 3...
November 28, 2016: Environmental Technology
https://www.readbyqxmd.com/read/27889179/estimation-of-rate-constants-of-pcb-dechlorination-reactions-using-an-anaerobic-dehalogenation-model
#6
Filiz Karakas, Ipek Imamoglu
This study aims to estimate anaerobic dechlorination rate constants (km) of reactions of individual PCB congeners using data from four laboratory microcosms set up using sediment from Baltimore Harbor. Pathway km values are estimated by modifying a previously developed model as Anaerobic Dehalogenation Model (ADM) which can be applied to any halogenated hydrophobic organic (HOC). Improvements such as handling multiple dechlorination activities (DAs) and co-elution of congeners, incorporating constraints, using new goodness of fit evaluation led to an increase in accuracy, speed and flexibility of ADM...
November 9, 2016: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/27887772/dechlorination-of-organochloride-waste-mixture-by-microwave-irradiation-before-forming-solid-recovered-fuel
#7
Zhen Liu, Han-Qing Wang, Xiao-Dong Zhang, Jian-Wen Liu, Yue-Yun Zhou
In order to form a modified solid recovered fuel (SRF) with low chlorine content, high calorific value and well combustion performance, low temperature microwave irradiation was applied to remove the chlorine of the organochloride waste mixture before they were mixed to form SRF. The optimizing conditions of final temperature, microwave absorbents and heating rate were also detected to obtain high dechlorination ratio and high ratio of hydrogen chloride (HCl) to volatiles. In the temperature range of 220-300°C, 280°C would be chose as the optimal low microwave modified temperature concerning at which the dechlorination ratio was high and ratio of HCl to volatiles was relatively high as well; The use of microwave absorbents of graphite and silicon carbide (SiC) had a pronounced effect on the dechlorination of organochloride waste mixture, and the dechlorination ratio was increased significantly which could be reached to 87%, almost 20% higher than absorbent absent sample; The heating rate should set be not too fast nor too slow, and there was no big difference between the heating rate of 13°C/min and 15°C/min; The content of Cl of modified SRF is dramatically decreased and reaches to a low level 0...
November 22, 2016: Waste Management
https://www.readbyqxmd.com/read/27886537/bioelectrochemical-approach-for-reductive-and-oxidative-dechlorination-of-chlorinated-aliphatic-hydrocarbons-cahs
#8
Agnese Lai, Federico Aulenta, Marina Mingazzini, Maria Teresa Palumbo, Marco Petrangeli Papini, Roberta Verdini, Mauro Majone
A sequential reductive-oxidative treatment was developed in this study in a continuous-flow bioelectrochemical reactor to address bioremediation of groundwater contaminated by trichloroethene (TCE) and less-chlorinated but still harmful intermediates, such as vinyl chloride. In order to optimize the anodic compartment, whereby the oxygen-driven microbial oxidation of TCE-daughter products occurs, abiotic batch experiments were performed with various anode materials poised at +1.20 V vs. SHE (i.e., graphite rods and titanium mesh anode coated with mixed metal oxides (MMO)) and setups (i...
November 22, 2016: Chemosphere
https://www.readbyqxmd.com/read/27869691/bacterial-biotransformation-of-pentachlorophenol-and-micropollutants-formed-during-its-production-process
#9
REVIEW
Eglantina Lopez-Echartea, Tomas Macek, Katerina Demnerova, Ondrej Uhlik
Pentachlorophenol (PCP) is a toxic and persistent wood and cellulose preservative extensively used in the past decades. The production process of PCP generates polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) as micropollutants. PCDD/Fs are also known to be very persistent and dangerous for human health and ecosystem functioning. Several physico-chemical and biological technologies have been used to remove PCP and PCDD/Fs from the environment. Bacterial degradation appears to be a cost-effective way of removing these contaminants from soil while causing little impact on the environment...
November 17, 2016: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/27866621/biogenic-fes-accelerates-reductive-dechlorination-of-carbon-tetrachloride-by-shewanella-putrefaciens-cn32
#10
Ying-Chao Huo, Wen-Wei Li, Chang-Bin Chen, Chen-Xuan Li, Raymond Zeng, Tai-Chu Lau, Tian-Yin Huang
Dissimilatory metal reducing bacteria (DMRB) widely exist in the subsurface environment and are involved in various contaminant degradation and element geochemical cycling processes. Recent studies suggest that DMRB can biosynthesize metal nanoparticles during metal reduction, but it is unclear yet how such biogenic nanomaterials would affect their decontamination behaviors. In this study, we found that the dechlorination rates of carbon tetrachloride (CT) by Shewanella putrefaciens CN32 was significantly increased by 8 times with the formation of biogenic ferrous sulfide (FeS) nanoparticles...
December 2016: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/27856620/genomic-characterization-of-dehalococcoides-mccartyi-strain-11a5-reveals-a-circular-extrachromosomal-genetic-element-and-a-new-tetrachloroethene-reductive-dehalogenase-gene
#11
Siyan Zhao, Chang Ding, Jianzhong He
Dehalococcoides mccartyi exhibits versatile capabilities to respire halogenated compounds under anaerobic conditions. In this study, we report the assembly and annotation of the complete genome of a chloroethene dechlorinating D. mccartyi strain 11a5. Bearing a 1,461,973 base-pair chromosome, strain 11a5 distinguishes itself from other D. mccartyi strains by possessing a 5,940 base-pair circular extrachromosomal genetic element which contains a reductive dehalogenase homolog. The whole genome of strain 11a5 harbors 31 putative reductive dehalogenase genes...
November 16, 2016: FEMS Microbiology Ecology
https://www.readbyqxmd.com/read/27844293/widespread-distribution-of-dehalococcoides-mccartyi-in-the-houston-ship-channel-and-galveston-bay-texas-sediments-and-the-potential-for-reductive-dechlorination-of-pcdd-f-in-an-estuarine-environment
#12
Anne-Sophie Charlotte Hieke, Robin Brinkmeyer, Kevin M Yeager, Kimberly Schindler, Saijin Zhang, Chen Xu, Patrick Louchouarn, Peter H Santschi
Sediments in the Houston Ship Channel and upper Galveston Bay, Texas, USA, are polluted with polychlorinated dibenzo-p-dioxins/furans (PCDD/F; ≤46,000 ng/kg dry weight (wt.)) with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic congener, contributing >50 % of the total toxic equivalents (TEQ) at most locations. We measured PCDD/F concentrations in sediments and evaluated the potential for enhanced in situ biodegradation by surveying for Dehalococcoides mccartyi, an obligate organohalide respiring bacterium...
November 14, 2016: Marine Biotechnology
https://www.readbyqxmd.com/read/27817900/impact-of-estuarine-gradients-on-reductive-dechlorination-of-1-2-3-4-tetrachlorodibenzo-p-dioxin-in-river-sediment-enrichment-cultures
#13
Hang T Dam, Max M Häggblom
Polychlorinated dibenzo-p-dioxins (PCDDs) are among the most persistent organic pollutants. Although the total input of PCDDs into the environment has decreased substantially over the past four decades, their input via non-point sources is still increasing, especially in estuarine metropolitan areas. Here we report on the microbially mediated reductive dechlorination of PCDDs in anaerobic enrichment cultures established from sediments collected from five locations along the Hackensack River, NJ and investigate the impacts of sediment physicochemical characteristics on dechlorination activity...
November 3, 2016: Chemosphere
https://www.readbyqxmd.com/read/27810532/mechanochemical-remediation-of-pcb-contaminated-soil
#14
Haizhu Wang, Jisu Hwang, Jun Huang, Ying Xu, Gang Yu, Wenchao Li, Kunlun Zhang, Kai Liu, Zhiguo Cao, Xiaohui Ma, Zhipeng Wei, Quhui Wang
Soil contaminated by polychlorinated biphenyls (PCBs) is a ubiquitous problem in the world, which can cause significant risks to human health and the environment. Mechanochemical destruction (MCD) has been recognized as a promising technology for the destruction of persistent organic pollutants (POPs) and other organic molecules in both solid waste and contaminated soil. However, few studies have been published about the application of MCD technology for the remediation of PCB contaminated soil. In the present study, the feasibility of destroying PCBs in contaminated soil by co-grinding with and without additives in a planetary ball mill was investigated...
October 27, 2016: Chemosphere
https://www.readbyqxmd.com/read/27809491/1-2-dichloroethane-exposure-alters-the-population-structure-metabolism-and-kinetics-of-a-trichloroethene-dechlorinating-dehalococcoides-mccartyi-consortium
#15
Koshlan Mayer-Blackwell, Maeva Fincker, Olivia Molenda, Benjamin Callahan, Holly Sewell, Susan Holmes, Elizabeth A Edwards, Alfred M Spormann
Bioremediation of groundwater contaminated with chlorinated aliphatic hydrocarbons such as perchloroethene and trichloroethene can result in the accumulation of the undesirable intermediate vinyl chloride. Such accumulation can either be due to the absence of specific vinyl chloride respiring Dehalococcoides mccartyi or to the inhibition of such strains by the metabolism of other microorganisms. The fitness of vinyl chloride respiring Dehalococcoides mccartyi subpopulations is particularly uncertain in the presence of chloroethene/chloroethane cocontaminant mixtures, which are commonly found in contaminated groundwater...
November 3, 2016: Environmental Science & Technology
https://www.readbyqxmd.com/read/27788401/electromagnetic-induction-of-nanoscale-zerovalent-iron-particles-accelerates-the-degradation-of-chlorinated-dense-non-aqueous-phase-liquid-proof-of-concept
#16
Tanapon Phenrat, Itsaraphong Kumloet
In this study, a novel electromagnetically enhanced treatment concept is proposed for in situ remediation of a source zone of chlorinated dense non-aqueous phase liquid (DNAPL) that is slowly dissolved, causing contaminated groundwater for centuries. Here, we used polystyrene sulfonate (PSS)-modified nanoscale zerovalent iron (NZVI) particles (ferromagnetic) in combination with a low frequency (LF) (150 kHz) AC electromagnetic field (EMF) to accelerate the degradation of the DNAPLs via enhanced dissolution and reductive dechlorination...
December 15, 2016: Water Research
https://www.readbyqxmd.com/read/27786438/microbial-catalyzed-reductive-dechlorination-of-polychlorinated-biphenyls-in-the-hudson-and-grasse-river-sediment-microcosms-determination-of-dechlorination-preferences-and-identification-of-rare-ortho-removal-pathways
#17
Yan Xu, Kelvin B Gregory, Jeanne M Vanbriesen
Biodegradation of polychlorinated biphenyls (PCBs) is an important transformation and detoxification route in the environment. To better understand the influence of PCB congener compositions on dechlorination, sediments from two rivers, Hudson and Grasse, and two PCB mixtures (PCB 5/12, 64/71, 105/114 and 149/153/170 in Mixture 1 and PCB 5/12, 64/71, 82/97/99, 144/170 in Mixture 2) were used for this microcosm study. The Grasse River sediment microcosms exhibited more extensive dechlorination than the Hudson River sediment microcosms...
October 27, 2016: Environmental Science & Technology
https://www.readbyqxmd.com/read/27783109/combination-of-zero-valent-iron-and-anaerobic-microorganisms-immobilized-in-luffa-sponge-for-degrading-1-1-1-trichloroethane-and-the-relevant-microbial-community-analysis
#18
Wenbing Wang, Yanqing Wu
1,1,1-Trichloroethane (1,1,1-TCA), a dense non-aqueous phase liquid (DNAPL), is relatively slow to remediate naturally; combination of zero-valent iron and immobilized microorganism is a potential means to accelerate DNAPL biodegradation. We first adopted high density luffa sponge (HDLS) as immobilized microorganism carrier. The experimental results demonstrated that (1) the supernatant liquid microorganisms were the optimal immobilized microorganisms for HDLS and (2) the combination of zero-valent iron and immobilized microorganisms accelerated 1,1,1-TCA transformation...
October 25, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27776856/graphene-oxide-mediated-rapid-dechlorination-of-carbon-tetrachloride-by-green-rust
#19
Li-Zhi Huang, Hans Christian B Hansen, Kim Daasbjerg
Graphene-based nanomaterials can mediate environmentally relevant abiotic redox reactions of chlorinated aliphatic hydrocarbons. In this study as low amounts as ∼0.007 % of graphene oxide (GO) was found to catalyze the reduction of carbon tetrachloride by layered Fe(II)-Fe(III) hydroxide (Green Rust, GR) in aqueous solutions with chloroform being the reduction product. On the basis of sorption studies of carbon tetrachloride onto the GO surface it is suggested that it is the amphiphilicity of GO, which initiates the reaction by providing a suitable reaction platform for the reagents...
February 5, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/27771950/sediment-monitored-natural-recovery-evidenced-by-compound-specific-isotope-analysis-and-high-resolution-pore-water-sampling
#20
Elodie Passeport, Richard Landis, Georges Lacrampe-Couloume, Edward J Lutz, Elizabeth Erin Mack, Kathryn West, Scott Morgan, Barbara Sherwood Lollar
Monitoring natural recovery of contaminated sediments requires the use of techniques that can provide definitive evidence of in situ contaminant degradation. In this study, a passive diffusion sampler, called "peeper", was combined with Compound Specific Isotope Analysis to determine benzene and monochlorobenzene (MCB) stable carbon isotope values at a fine vertical resolution (3 cm) across the sediment water interface at a contaminated site. Results indicated significant decrease in concentrations of MCB from the bottom to the top layers of the sediment over 25 cm, and a 3...
October 23, 2016: Environmental Science & Technology
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