Research on the long-term effectiveness of composite functional materials for in-situ remediation of chlorinated hydrocarbon contaminated groundwater
In order to remediate chlorinated hydrocarbons contaminated ground water,a bioactive composite functional material was developed with coconut shell biochar and zero-valent iron as main raw materials.A field pilot test was performed to treat chlorinated hydrocarbons contaminated groundwater at a site in Jiangsu province.The field monitoring data revealed that the composite functional material could continuously release organic carbon and iron,facilitating the growth of dechlorinating bacteria.The 16S rRNA gene sequencing showed that after 1140 days of PRB operation,the relative abundance of dechlorinating bacteria in the composite functional materials(1.9%~8.3%)was higher than that in the initial PRB material(0.5%).During 1140 days of PRB operation,the surface morphology of the composite functional material remained stable.The removal efficiencies of various chlorinated hydrocarbons compounds by PRB ranged from 13.7%to 100%during the 2000-day operation period.The composite functional material can effectively remove chlorinated hydrocarbons from groundwater through the combined mechanism of adsorption,iron reduction and microbial degradation.The research could provide important technical support for the in-situ remediation of groundwater contaminated with chlorinated hydrocarbons.