A novel approach for the in situ bioremediation of acidified, nitrate-contaminated groundwater was developed. Ethanol was introduced into the groundwater to enhance the activity of intrinsic denitrifying micro-organisms. Infiltration of the carbon source was made via an infiltration gallery constructed in the unsaturated zone to avoid clogging problems and to allow wider distribution of ethanol in the groundwater. The changes in the groundwater geochemistry and soil gas composition were monitored at the site to evaluate the efficiencies of the infiltration system and nitrate removal. Moreover, the impact of pH and ethanol addition on the denitrification rate was studied in laboratory. A reduction of 95% was achieved in the groundwater nitrate concentrations during the study. Neither clogging problems nor inefficient introduction of ethanol into the saturated zone were observed. Most crucial to the denitrifying communities was pH, values above 6 were required for efficient denitrification.
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http://dx.doi.org/10.1016/j.watres.2014.06.013 | DOI Listing |
J Hazard Mater
January 2025
School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, South Korea. Electronic address:
Chlorinated ethenes are prevalent contaminants in industrial wastewater that detrimentally affect human health. As elevated tetrachloroethene (PCE) concentrations (18.0-18.
View Article and Find Full Text PDFEnviron Pollut
January 2025
Divisão de Recursos Microbianos, Centro Pluridisciplinar de Pesquisas Químicas, Biológicas e Agrícolas (CPQBA), Universidade Estadual de Campinas (UNICAMP), CEP 13148-218, Paulínia, SP, Brasil.
The use of biofuel blends with fossil fuels is widespread globally, raising concerns over novel contamination types in environments impacted by these mixtures. This study investigates the microbial functional in soils contaminated by biofuel and fossil fuel blends and subjected to various bioremediation treatments. Using metagenomic analysis, it was compared hydrocarbon degradation functional profiles across areas polluted with ethanol/gasoline and biodiesel/diesel blends.
View Article and Find Full Text PDFEnviron Res
January 2025
School of Resources and Environment, Northeast Agricultural University, Harbin 150030, PR China. Electronic address:
The severe contamination of the plasticiser dibutyl phthalate (DBP) in agriculture soils is often accompanied by a decrease in nutrient utilisation. Though the combined application of a variety of microorganisms can simultaneously address the problems of soil contamination and nutrient deprivation, the activity and function of microorganisms can be severely inhibited by DBP, and studies on their protection under DBP contamination are almost non-existent. In this study, a compound bacterial agent KPSB was prepared by optimising with FeO-modified biochar loaded with DBP-degrading bacterium Enterobacterium sp.
View Article and Find Full Text PDFBiotechnol Bioeng
January 2025
Department of Biochemistry and Molecular Biology, College of Life Sciences, Nankai University, Tianjin, China.
The bioaugmentation performance is severely reduced in the treatment of high-saline pesticide wastewater because the growth and degradation activity of pesticide degraders are significantly inhibited by high salt concentrations. In this study, a heterologous biodegradation pathway comprising the seven genes mpd/pnpABCDEF responsible for the bioconversion of p-nitrophenol (PNP)-substituted organophosphorus pesticides (OPs) into β-oxoadipate and the genes encoding Vitreoscilla hemoglobin (VHb) and green fluorescent protein (GFP) were integrated into the genome of a salt-tolerant chassis Halomonas cupida J9, to generate a genetically engineered halotolerant degrader J9U-MP. RT-PCR assays demonstrated that the nine exogenous genes are successfully transcribed to mRNA in J9U-MP.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
January 2025
Department of Environmental Technology, Wageningen University & Research, P.O. Box 17, 6700 AA, Wageningen, The Netherlands.
The biodegradation of organic aromatic compounds in subsurface environments is often hindered by limited dissolved oxygen. While oxygen supplementation can enhance in situ biodegradation, it poses financial and technical challenges. This study explores introducing low-oxygen concentrations in anaerobic environments for efficient contaminant removal, particularly in scenarios where coexisting pollutants are present.
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