In dense nonaqueous phase liquid (DNAPL) contaminant source zones, aqueous concentrations of trichloroethene (TCE) in groundwater may approach saturation levels (8.4 mM). It is generally believed that such saturation concentrations are toxic to organohalide-respiring bacteria (OHRB), thus limiting the effectiveness of bioremediation.
View Article and Find Full Text PDFThermal remediation is an effective technology for organic contaminant remediation. However, the application of thermal remediation may have negative effects on soil properties and ecological functions, which requires further investigation. Based on a pilot test of electrical resistance heating remediation (ERH), soil samples were collected at different locations after heating for 116 days.
View Article and Find Full Text PDFThe coupling of thermal remediation with microbial reductive dechlorination (MRD) has shown promising potential for the cleanup of chlorinated solvent contaminated sites. In this study, thermal treatment and bioaugmentation were applied in series, where prior higher thermal remediation temperature led to improved TCE dechlorination performance with both better organohalide-respiring bacteria (OHRB) colonization and electron donor availability. The 60 °C was found to be a key temperature point where the promotion effect became obvious.
View Article and Find Full Text PDFPFASs and chlorinated solvents are the common co-contaminants in soil and groundwater at firefighter training areas (FTAs). Although PFASs mixtures could have adverse impacts on bioremediation of trichloroethylene (TCE) by inhibiting Dehalococcoides (Dhc), little is known about the effect and contribution of PFOA or PFOS on dechlorination of TCE by non-Dhc organohalide-respiring bacteria (OHRB). To study this, PFOA and PFOS were amended to the growth medium of a non-Dhc OHRB-containing enrichment culture to determine the impact on dechlorination.
View Article and Find Full Text PDFThe challenge of simultaneous removal of nitrobenzene (NB), aniline (AN) and nitrate from groundwater in a single bioreactor is mainly attributed to the persistence of AN to degradation with anoxic denitrification conditions. In this work, simultaneous removal of NB (100 μM), AN (100 μM) and nitrate (1 mM) was achieved within 8 h with a COD/N ratio of 8 in a vertical baffled biofilm reactor (VBBR). By setting DO concentration at 0.
View Article and Find Full Text PDFThe widespread use of antibiotics has accelerated the development of antibiotic resistance genes (ARGs), which are now recognized as emerging environmental contaminants that pose a high risk to public health. In this study, simultaneous antibiotic and ARGs removal and bioelectricity generation was explored in a microbial electro-Fenton system using erythromycin (ERY) as a model antibiotic compound. The results showed that ERY could be degraded, with an average removal efficiency of 88.
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