Enhancing the removal of chlorinated hydrocarbons from groundwater using a new BL5 microorganism with functional CS@ZVI materials

The remediation of the chlorinated organic compounds via zero-valent iron (ZVI) and microorganisms coupling method in the groundwater has received increasing attention and research. However, the addition of external microorganisms has poor adaptability in complex environmental applications, and ZVI is easily inactivated and has weak long-term degradation performance in the environment. The existing modification preparation of ZVI modified materials seem relatively lacking economical and environmentally friendly methods. This study obtained a new type of highly efficient degradation bacterium BL5, and introduced an economical and simple method for preparing the functional CS@ZVI biological stimulation materials. The performances of CS@ZVI-BL5 systems for the removal of TCE, chloroform , 1,2-dichloroethane, and chlorobenzene were all reached 100 % after 12 days, which was significantly improved the degradation efficiency by the CS@ZVI or BL5 (95.65 %, 93.64 %, 90.54 %, 88.85 %) alone. This is the first method that extracted and screened an autochthonous high-efficiency degrading bacterium from contaminated sites, and developed a biological stimulation material to improve the remediation. Here we demonstrate that the modified CS@ZVI with BL5 microorganisms synergistically enhanced the degradation performance.