基于多相流数值模拟的某石油污染场地地下水中VOCs自然衰减过程识别及能力评估  

Multiphase flow modeling of natural attenuation of volatile organic compounds(VOCs)in a petroleum contaminated site

作　　者：沈晓芳 万玉玉[3] 王利刚 苏小四[2,3] 董维红[2,3] SHEN Xiaofang;WAN Yuyu;WANG Ligang;SU Xiaosi;DONG Weihong(College of Construction Engineering,Jilin University,Changchun 130000,China;Institute of Water Resources and Environment,Jilin University,Changchun 130000,China;Ministry of Education Key Laboratory of Groundwater Resources and Environments,Jilin University,Changchun 130000,China;Jilin Branch of China Kunlun Engineering Co.,Ltd.,Jilin 132100,China)

机构地区：[1]吉林大学建设工程学院,吉林长春130000 [2]吉林大学水资源与环境研究所,吉林长春130000 [3]吉林大学地下水资源与环境教育部重点实验室,吉林长春130000 [4]中国昆仑工程有限公司吉林分公司,吉林吉林132100

出　　处：《地学前缘》2021年第5期90-103,共14页Earth Science Frontiers

基　　金：国家重点研发计划项目(2018YFC1800901);吉林大学博士研究生交叉学科科研资助计划项目(101832020DJX073)。

摘　　要：监测自然衰减(monitoring natural attenuation,MNA)技术是目前普遍认可的去除地下水中挥发性有机污染物(volatile organic compounds,VOCs)的技术。但受其修复周期长、监测费用昂贵等因素的影响,实地开展MNA技术修复污染场地具有一定的局限性。基于此,本研究运用多相流数值模拟手段识别了某石油污染场地内典型VOCs污染物(苯、甲苯、萘)在地下水中的自然衰减过程并评估了其自然衰减能力。结果表明:采用TMVOC所建立的多相流数值模拟模型能较好地预测和识别VOCs在地下水中的衰减规律;在研究区中,苯、甲苯和萘由于理化性质差异,在地下水中的污染羽分布特征不同,其自然衰减过程受挥发、吸附和生物降解作用的影响程度也不同;挥发和生物降解作用对VOCs自然衰减的影响程度均为苯>甲苯>萘,而吸附作用对VOCs自然衰减的影响程度为萘>甲苯>苯;在污染源被阻断的前提下,苯、甲苯和萘分别在泄漏发生7.0、6.5和6.0年后通过自然衰减达到理想去除效果。本文研究成果可以为水文地质条件类似的VOCs污染场地MNA修复方案的制定和修复效果评估提供理论支撑。The monitored natural attenuation(MNA)technology has become a generally recognized technology for remediation of VOCs.However,this technology,owing to the long remediation period and expensive monitoring costs,has certain limitations in real world applications.In this study,we use multiphase flow numerical simulation to identify the natural attenuation process and assess the attenuation capacity for typical VOCs(benzene,toluene,naphthalene)in a petroleum contaminated site.The results show that the multiphase flow numerical model established by TMVOC can predict the attenuation laws of VOCs in groundwater.In the study area,the pollution plumes of benzene,toluene and naphthalene in groundwater have different distribution patterns due to the differences in their physicochemical properties,and the natural attenuation process is affected to various degrees by volatilization,adsorption and microbial degradation.The effects of volatilization and biodegradation on VOC remediation are benzene>toluene>naphthalene,while the effect of adsorption is naphthalene>toluene>benzene.Assuming the pollution source is blocked,benzene,toluene and naphthalene are predicted to achieve ideal remediation through MNA at 7.0,6.5 and 6.0 years,respectively,after oil leak.The above simulation results can provide theoretical support for the implementation and evaluation of MNA technology in remediation of VOC contaminated sites under similar hydrogeological conditions.

关 键 词：VOCS 自然衰减 多相流数值模拟 地下水 

分 类 号：X523[环境科学与工程—环境工程]