Synergistic effects of acclimated bacterial community and zero valent iron for removing 1,1,1‐trichloroethane and 1,4‐dioxane co‐contaminants in groundwater

BACKGROUND Ttrichloroethane acid (TCA) and 1,4‐dioxane have caused significantly combined pollution in soil and groundwater. By establishing the zero valent iron (ZVI) and the acclimated bacterial community coupled system, this study aimed to improve the treatment of 1,1,1‐trichloroethane (TCA) and 1,4‐dioxaneco‐contamination in groundwater and to investigate the synergistic mechanism of ZVI and the acclimated bacterial community coupled system for transformation of TCA and 1,4‐dioxane. RESULTS The results showed that the ZVI effectively strengthened the acclimated bacterial community to degrade 70 mg L‐1 TCA and 1,4‐dioxane with enhancement factors (Q) of 1.20 and 2.20. The removal percentages reached 97.8% and 92.5%, respectively. The degradation rate was consistent with the first‐order reaction kinetics. The reductive dechlorination byproducts of TCA were 1,1‐dichloroethane (DCA) and chloroethane (CA), while 1,4‐dioxane was mainly converted to CO2 in the system. The corrosion products on the ZVI surface were mainly FeCO3 and FeS. Phylogenetic analysis revealed that the dominant bacteria were dechlorinating bacteria (DhB), sulfate reducing bacteria (SRB) and iron‐reducing bacteria (IRB) in the microbial community. CONCLUSION ZVI coupled with an acclimated bacterial community is a potential technique to apply to deal with TCA and 1,4‐dioxane co‐contaminants in groundwater. © 2018 Society of Chemical Industry