欢迎访问《环境科学学报》编辑部网站！

快速检索			高级检索

研究报告

Simulation of in-situ bioremediation of chlorinated hydrocarbon contamination in groundwater

摘要：原位生物修复技术是修复地下水中挥发性氯代烃（VCHs）污染的重要手段之一.精细模拟修复过程是实现高效修复的关键.然而以往多数模拟VCHs修复过程的研究并未全面考虑VCHs自然衰减性质，势必会造成预测误差.因此，本研究针对当前VCHs原位生物修复模型的局限性，提出考虑VCHs自然衰减性质的原位生物修复Monod-Natural attenuation（M-Na）模型.该模型主要将自主开发的M-Na模型的源代码以用户自定义反应模块的形式嵌入到RT3D中.通过注入乳酸提供氢气进行原位生物修复含水层中四氯乙烯（PCE）污染，验证M-Na模型的精确性，并分析了修复过程参数变化（包括乳酸的注入浓度和速率）对修复效果的影响.算例分析结果表明，VCHs的自然衰减作用可以将修复产物乙烯（ETH）浓度提高10%左右，这在VCHs污染修复模拟过程中不可忽略；同时算例中乳酸的最佳注入浓度为30 mg·L^-1，最佳注入速率为200 m³·d^-1.本研究成果有望为地下水VCHs污染原位生物修复精细模拟及高效修复提供模型参考.

Abstract：In-situ bioremediation technology is one of the most important methods for volatile chlorinated hydrocarbons（VCHs）remediation in groundwater. Accurate simulation of the remediation process is critical for high-efficiency remediation. Nevertheless， most of the previous studies did not consider the natural attenuation of VCHs， which would lead to the inaccuracy in prediction. Therefore， this paper has proposed a Monod-Natural attenuation（M-Na）model of in-situ bioremediation considering the natural attenuation of VCHs to overcome the limitation of current VCHs in-situ bioremediation model. The source code of the M-Na model was coupled in RT3D in the form of user-defined reaction module. In this paper， hydrogen was provided by injecting lactic acid for in-situ bioremediation of tetrachloroethylene（PCE）contamination in aquifer to verify the accuracy of M-Na model and analyze the influence of controlling parameters（including lactic acid injection concentration and rate）of the remediation process. The simulation results have shown that the concentration of ethylene（ETH） increased about 10% due to the natural attenuation of VCHs， which could not be neglected. Meanwhile， the lactic acid optimal concentration is 30 mg·L^-1 and the optimal injection rate is 200 m³·d^-1 for the study area. This study is expected to provide accurate simulation model for in-situ bioremediation of groundwater contaminated by VCHs.