长三角某石油烃污染场地地下水原位电阻加热修复技术工程应用

Application of In-Situ Electrical Resistance Heating Technology to Petroleum Hydrocarbons in Groundwater at a Contaminated Site in the Yangtze River Delta

以我国长三角地区某典型机械厂石油烃污染场地修复工程为案例,阐述原位电阻加热技术对有机污染地下水的原位修复过程。通过原位电阻加热将水土同步加热至近100℃,将污染物从土壤和地下水中脱附出来,配以多相抽提井将污染物抽出并进行后续处理;设置地下温度、压力监测点,动态监测修复过程;设置地下水监测井,定期采集地下水样品,评估修复效果。地下水样品中污染物浓度监测结果表明,加热50 d后(加热中期)各监测点位的地下水石油烃的修复达标率超过65%,加热108 d后(加热后期)达标率达100%。后期尚需对地下水污染物开展进一步跟踪监测,验证该技术的持久性和彻底性,为后续技术示范推广与应用提供可靠的数据和成功的经验支撑。

This article introduces a remediation case of petroleum hydrocarbon pollution in a typical machinery factory of the Yangtze River Delta region,and expounds the process of in-situ electrical resistance heating technology during remediation of organic pollutants in groundwater.The groundwater and soil were warmed simultaneously to approximately 100℃by the heat that resistance generated in electric field,and the pollutants were desorbed from groundwater and soil and extracted through multi-phase extraction wells,which were treated subsequently on the ground.Amounts of underground temperature and pressure monitoring wells were set to reveal remediation process,and some groundwater monitoring wells were also built to collect groundwater samples regularly and evaluate remediation efficiency.Results of contaminants concentration in groundwater showed that after 50 days of in-situ heating(so-called interim period of remediation)petroleum hydrocarbon concentrations of 65%samples collected in the monitoring wells were below the remediation target value,and after 108 days(last period of remediation)the number reached 100%.In the later stage,further tracking and monitoring of petroleum hydrocarbon concentration in groundwater is needed to verify long-term remediation efficiency of the technology and provide credible data and successful experience for its subsequent application.