Enhanced Reduction Of Aged ZVI By Shewanella Putrefaciens To Degradate Organic Pollutants In Groundwater

Halogenated organic compounds(including PCBs,chlorophenols)are mostly xenobiotic compounds and are typical persistent organic pollutants.Due to its chemical stability,poor biodegradability,typical organic pollutants,such as chlorinated aromatic hydrocarbons,could accumulate in the environment,such as sediments or soil organic matter,and enter the food chain through bioaccumulation.In addition,they also have triadimetric and genetic toxicity,which cause persistent pollution to environment.Researchers have made a large number of systematic studies on the mechanism of biodegradation,advanced oxidation and zero-valent reduction to degradation persistent organic pollutants,among which,interactions between iron-reducing bacteria and iron oxides have received widespread attention for degradation organic pollutants.The applications of zero valent iron(ZVI)for degradation of contaminants have been received widespread attention due to its controllable particle size,high reactivity and abundant reactive surface sites.However,ZVI has a strong tendency to surface oxided which blocked the surface active sites and decreases the reaction rate.It has been reported that oxidized minerals often formed on the surface of ZVI.The negative effect of iron corrosion products on the reactivity of ZVI has become a major issue in the further development of ZVI technology.It is therefore significant to develop an method able to re-activation the aged ZVI to enhance removal efficiency of contaminants.In this work,based on EDDS has strong ability to complex Fe(?)and biochar has large specific surface area and contains many functional groups,it could be used to increase the reductive rate of FeOOH or aged ZVI by iron reducing bacteria.The aim is to establish the FeOOH,iron reducing bacteria and EDDS or biochar coupled system.chlorinated organic was selected as a representative target contaminants.The mechanism of EDDS and biochar enhance reductive of FeOOH to degradate chlorinated organic was discussed.This study establish the system that enhance the activity of aged ZVI.It provides a theoretical basis for the popularization and application of zero valent iron technology in environmental remediation,and provides technical support for developing new groundwater remediation materials.