This study focused on the investigation of (i) the tetrachloroethene (PCE) toxicity threshold of a reductively dechlorinating mixed culture containing Dehalococcoides spp., (ii) the adsorption of PCE on different types of granular activated carbon (GAC), and (iii) the bioavailability and reductive dechlorination in the presence of GAC. The abundance of Dehalococcoides spp. detected by quantitative real-time polymerase chain reaction (qPCR) was found to increase by 2-4 orders of magnitude during degradation of PCE. No degradation occurred at dissolved concentrations beyond 420 μM (70 mg/L). Different adsorption isotherms were determined for thermally and chemically activated carbons. The addition of GAC to biological assays reduced the dissolved PCE concentration below the toxicity threshold. The combination of microbial reductive dechlorination with GAC adsorption proved to be a promising method for remediation of groundwater contaminated by high concentrations of chloroethenes.
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http://dx.doi.org/10.1016/j.biortech.2011.09.119 | DOI Listing |
Water Res
January 2025
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), 1#, Dongsanlu, Erxianqiao, Chengdu 610059, Sichuan, PR China; State Environmental Protection Key Laboratory of Synergetic Control and Joint Remediation for Soil & Water Pollution (Chengdu University of Technology), 1#, Dongsanlu, Erxianqiao, Chengdu 610059, Sichuan, PR China. Electronic address:
Electrochemical reduction technology is a promising method for addressing the persistent contamination of groundwater by chlorinated hydrocarbons. Current research shows that electrochemical reductive dechlorination primarily relies on direct electron transfer (DET) and active hydrogen (H) mediated indirect electron transfer processes, thereby achieving efficient dechlorination and detoxification. This paper explores the influence of the molecular charge structure of chlorinated hydrocarbons, including chlorolefin, chloroalkanes, chlorinated aromatic hydrocarbons, and chloro-carboxylic acid, on reductive dechlorination from the perspective of molecular electrostatic potential and local electron affinity.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark. Electronic address:
Nitrogen (N) doping of biomass prior pyrolysis has been identified as an effective approach for enhancing biochar catalytic reactivity. However, high-temperature pyrolysis of N-rich biomass may produce N-devoid biochars with high reactivity, calling for attention to the true causes of the reactivity increases and the role of nitrogen. In this study, N-doped wheat straw biochar (N-BC) materials were produced using urea as N dopant and different pyrolysis conditions, and their catalytic reactivity assessed for the reduction of trichloroethylene (TCE) by green rust (GR), a layered Fe(II)Fe(III) hydroxide.
View Article and Find Full Text PDFChemosphere
January 2025
MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China.
Trichloroethylene (TCE) is a common chlorinated hydrocarbon contaminant in soil and groundwater, and reductive dechlorination is a biological remediation. However, the TCE reductive dechlorination often stagnates in the stage of cis-1,2-dichloroethylene (cDCE) and chloroethylene (VC). Anaerobic/aerobic sequential degradation provides a new approach for the complete detoxification of TCE, while there has been no systematic summary of bacteria, enzymes, and pathways in the synergistic process.
View Article and Find Full Text PDFChemosphere
January 2025
Department of Civil and Environmental Engineering, University of Massachusetts Lowell, Massachusetts, United States. Electronic address:
There is significant interest in monitoring abiotic decomposition of chlorinated solvents at contaminated sites due to large uncertainties regarding the rates of abiotic attenuation of trichloroethylene (TCE) and perchloroethylene (PCE) under field conditions. In this study, an innovative passive sampling tool was developed to quantify acetylene, a characteristic product of abiotic reduction of TCE or PCE, in groundwater. The sampling mechanism is based on the highly specific and facile click reaction between acetylene and an azide compound to form a biologically and chemically stable triazole product.
View Article and Find Full Text PDFFront Microbiol
December 2024
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, China.
Organohalide-respiring bacteria (OHRB) play a pivotal role in the transformation of organohalogens in diverse environments. This bibliometric analysis provides a timely overview of OHRB research trends and identifies knowledge gaps. Publication numbers have steadily increased since the process was discovered in 1982, with fluctuations in total citations and average citations per publication.
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