Combination of steam-enhanced extraction and electrical resistance heating for efficient remediation of perchloroethylene-contaminated soil:Coupling merits and energy consumption  

作　　者：Rui Yue Zhikang Chen Liujun Liu Lipu Yin Yicheng Qiu Xianhui Wang Zhicheng Wang Xuhui Mao 

机构地区：[1]School of Resource and Environmental Sciences,Wuhan University,Wuhan 430079,China [2]China State Science Dingshi Environmental Engineering Company,Beijing 100020,China

出　　处：《Frontiers of Environmental Science & Engineering》2022年第11期249-260,共12页环境科学与工程前沿（英文）

基　　金：supported by the National Key R&D Program of China(No.2019YFC1805700).

摘　　要：In situ thermal desorption(ISTD)technology effectively remediates soil contaminated by dense nonaqueous phase liquids(DNAPLs).However,more efforts are required to minimize the energy consumption of ISTD technology.This study developed a laboratory-scale experimental device to explore the coupling merits of two traditional desorption technologies:steam-enhanced extraction(SEE)and electrical resistance heating(ERH).The results showed that injecting high-density steam(>1 g/min)into loam or clay with relatively high moisture content(>13.3%)could fracture the soil matrix and lead to the occurrence of the preferential flow of steam.For ERH alone,the electrical resistance and soil moisture loss were critical factors influencing heating power.When ERH and SEE were combined,preheating soil by ERH could increase soil permeability,effectively alleviating the problem of preferential flow of SEE.Meanwhile,steam injection heated the soil and provided moisture for maintaining soil electrical conductivity,thereby ensuring power stability in the ERH process.Compared with ERH alone(8 V/cm)and SEE alone(1 g/min steam),the energy consumption of combined method in remediating perchloroethylene-contaminated soil was reduced by 39.3%and 52.9%,respectively.These findings indicate that the combined method is more favorable than ERH or SEE alone for remediating DNAPL-contaminated subsurfaces when considering ISTD technology.

关 键 词：Steam-enhanced extraction Electrical resistance heating Dense nonaqueous phase liquid Soil remediation Energy consumption 

分 类 号：S15[农业科学—土壤学]