温度对曝气抽提修复地下水中乙苯影响研究  

Effect of Temperature on the Remediation of Ethylbenzene in Groundwater by Aeration Extraction

作　　者：张雷[1] 皇甫辉远 苗月 曹伟锴 ZHANG Lei;HUANGFU Huiyuan;MIAO Yue;CAO Weikai(School of Earth Science,Northeast Petroleum University,Daqing 163318,China;Daqing Oil Field Co.Ltd.,Daqing 163000,China)

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318 [2]大庆油田有限责任公司,黑龙江大庆163000

出　　处：《环境科学与技术》2022年第12期70-77,共8页Environmental Science & Technology

基　　金：国家自然科学基金项目(41877489);中国博士后科学基金项目(2017M621201);黑龙江省优秀青年基金项目(JJ2020YX0502)。

摘　　要：中国北方地区冬季浅层地下水温度在4~10℃,特别是冬季,温度低于10℃,低温环境影响污染物的传质过程,导致常规的曝气-抽提(AS)修复效果差。基于此,作者以苯系物污染的地下水环境为研究对象,以乙苯作为代表性污染物,建立热空气强化AS修复二维箱体模拟装置,探究温度对于含水层乙苯去除过程中的影响效应。结果表明,含水层温度随着曝气温度提高,中上层温度场呈现“U”型分布,曝气后的乙苯浓度分布近区域“U”字形,这与曝气影响区域呈现的流型和热传递的传热机制是对应的。经过3 d修复,60℃相同时间内乙苯去除率较30℃提高2倍,乙苯去除效率为87.73%,乙苯浓度低于地下水Ⅳ类标准值0.6 mg/L。结果表明热空气温度通过传导影响地下水层温度,进而影响污染物和污染物饱和分压变化,提高挥发去除效率,提高修复效果。文章可为中国北方地区低温浅层土地下水苯系物污染修复提供技术支持。The temperature of shallow groundwater in northern China in winter is 4~10℃,especially in winter,the temperature is lower than 10℃,and the low-temperature environment affects the mass transfer process of pollutants,resulting in the poor repair effect of conventional aeration extraction.Based on this,the author takes the groundwater environment polluted by benzene series as the research object and ethylbenzene as the representative pollutant,establishes a twodimensional box simulation device for hot air enhanced AS remediation,and explores the effect of temperature on the removal of ethylbenzene in the aquifer.The results show that with the increase of aeration temperature,the temperature field in the middle and upper layer presents a“U”shape distribution,and the concentration distribution of ethylbenzene after aeration is close to the“U”shape,which corresponds to the flow pattern and heat transfer mechanism in the aeration affected area.After three-day repair,the removal rate of ethylbenzene at 60℃is twice higher than that at 30℃,the removal efficiency of ethylbenzene is 87.73%,and the concentration of ethylbenzene is lower than 0.6 mg/L(the standard value of classⅣgroundwater is 0.6 mg/L).The results show that the hot air temperature affects the temperature of groundwater layer through conduction,and then affects the pollutants,therefore how does the saturated partial pressure of pollutants change,improve the volatilization removal efficiency and improve the remediation effect,would provide technical support for the remediation of benzene series pollution in low-temperature shallow land in northern China.

关 键 词：热强化 曝气抽提 修复 乙苯 地下水 

分 类 号：X523[环境科学与工程—环境工程]