Using CO_(2)and oxidants for in situ regeneration of permeable reactive barriers for leachate-contaminated groundwater  

作　　者：Fangming Xu Xingshen Luo Junlong Huang Yuecen Dong Kaixuan Zheng Yanting Liu Yanjun Liu Hongtao Wang 

机构地区：[1]School of Environment,Tsinghua University,Beijing 100084,China [2]School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China [3]Zhongye Changtian International Engineering Co.Ltd.,Changsha 410205,China

出　　处：《Journal of Environmental Sciences》2024年第11期152-163,共12页环境科学学报（英文版）

摘　　要：Groundwater contamination near landfills is commonly caused by leachate leakage,and permeable reactive barriers(PRBs)are widely used for groundwater remediation.However,the deactivation and blockage of the reactive medium in PRBs limit their long-term effectiveness.In the current study,a new methodology was proposed for the in situ regeneration of PRB to remediate leachate-contaminated groundwater.CO_(2)coupled with oxidants was applied for the dispersion and regeneration of the fillers;by injecting CO_(2)to disperse the fillers,the permeability of the PRB was increased and the oxidants could flow evenly into the PRB.The results indicate that the optimumfiller proportion was zero-valent iron(ZVI)/zeolites/activated carbon(AC)=3:8:10 and the optimum oxidant proportion was COD/Na_(2)S_(2)O_(8)/H_(2)O_(2)/Fe^(2+)=1:5:6:5;the oxidation system of Fe^(2+)/H_(2)O_(2)/S_(2)O_(8)^(2−)has a high oxidation efficiency and persistence.The average regeneration rate of zeolites was 72.71%,and the average regeneration rate of AC was 68.40%;the permeability of PRB also increased.This technology is effective for the remediation of landfills in China that have large contaminated areas,an uneven pollutant concentration distribution,and a long pollution duration.The purification mode of long-term adsorption and short-time in situ oxidation can be applied to the remediation of long-term high-concentration organically polluted groundwater,where pollution sources are difficult to cut off.

关 键 词：Landfill leachate Groundwater remediation PRB in situ regeneration Advanced oxidation technology 

分 类 号：X523[环境科学与工程—环境工程]