Synergistic Effects of Adding a Substrate and an Organic Reductant for Stimulating the Bioremediation of 4-chloronitrobenzene-contaminated Soil

Abstract Background:Soil contaminated with 4-chloronitrobenzene (4NCB) is resistant to microbial degradation due to the electron-withdrawing properties of the nitro and chloro groups in 4NCB. Currently, sufficient information is not available on how to use biostimulation strategies to enhance the bioremediation of 4NCB-contaminated soil.Results:In the present study, a novel strategy was developed by utilizing the synergistic effects of adding an organic reductant (ascorbic acid, VC) and an organic nitrogen source (peptone) to stimulate the biodegradation of 4NCB-contaminated soil. Using this strategy, the bioremediation of 1 g-4NCB/ kg-1 soil could be completed within 8 days in soil batch reactors. Furthermore, the study discovered two 4NCB cometabolic intermediates in the soil reactors added with peptone and VC, and for the first time, 4NCB was transformed to 4-chlorofromanilide.Conclusion:The proposed strategy is promising because it is highly efficient, easy to control and involves a non-toxic, environmentally friendly substrate/reductant.). Finally, this approach warrants future studies to extend its applications to soils contaminated with other nitroaromatic compounds.