研究报告
王梦杰,范婷婷,王祥,夏菲洋,姜登登,孔令雅,丁达,张胜田,邓绍坡.典型农药污染场地地下水中氯代脂肪烃自然衰减研究[J].环境科学学报,2022,42(6):155-166
典型农药污染场地地下水中氯代脂肪烃自然衰减研究
- Study on natural attenuation of chlorinated aliphatic hydrocarbons in groundwater of typical pesticide contaminated sites
- 基金项目:国家重点研发计划(No.2018YFC1803100)
- 王梦杰
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 范婷婷
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 王祥
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 夏菲洋
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 姜登登
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 孔令雅
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 丁达
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 张胜田
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 邓绍坡
- 生态环境部南京环境科学研究所,南京 210042;国家环境保护土壤环境管理与污染控制重点实验室,南京 210042
- 摘要:氯代脂肪烃(CAH)污染地下水在我国化工行业场地中十分普遍,严重影响场地再开发利用和周边居住人群的健康安全.监测自然衰减(MNA)修复技术是污染场地地下水修复技术中最具有效性和高成本效益的方法之一,而目前我国应用MNA技术修复污染场地还处于试点阶段,没有完整实施MNA技术的工程应用实例.以某农药场地地下水中CAH为研究对象,从CAH污染物的浓度变化、天然生物降解现状评价和衰减速率3个方面开展为期4年的CAH自然衰减修复实践研究.研究结果表明,监测井MW2-1为核心污染区,主要污染物为1,2-二氯乙烷(1,2-DCA)、氯乙烯(VCE)、氯仿、顺-1,2-二氯乙烯、1,1-二氯乙烷和氯乙烷,浓度呈波动式下降趋势,且下降趋势明显.除了MW2-1的VCE和1,2-DCA、MW2-5的VCE以及MW2-2的1,2-DCA的浓度高于风险控制值,其他点位污染物浓度均低于相应风险控制值.基于典型地球化学参数开展的微生物降解评估结果表明,该地块大部分区域微生物降解能力不足,而在污染物浓度比较高的监测点位,微生物具有显著的降解能力.地下水中CAH衰减速率范围为0.0001~0.0040 d-1,超标点位的VCE和1,2-DCA通过自然衰减达到修复目标所需要的最长时间分别为7.2 a和5.4 a,建议该场地需要联合化学刺激等其他主动修复技术以强化其自然衰减过程.通过持续4 a的MNA修复技术监控可聚焦高浓度污染区边界,为下一阶段采取主动修复提供基础数据.本研究将为开展MNA技术修复有机物污染场地提供技术支持和科学指导.
- Abstract:Chlorinated aliphatic hydrocarbons (CAH) pollution in groundwater is very common in chemical industry sites of China, which seriously affects site redevelopment and health of surrounding residents. Monitoring natural attenuation (MNA) remediation technology is one of the most high-efficient and cost-effective methods for contaminated sites remediation. Up to now, the application of MNA to remediate contaminated sites in China is still in the pilot stage. The complete engineering application of MNA has not been applied to contaminated site remediation. In this study, CAH in groundwater of a pesticide site were selected as the representative contaminants. The change of concentrations, evaluation of microbial degradation ability, and attenuation rate were investigated during a four-year of CAH natural attenuation remediation practice. The results showed that MW2-1 was the core pollution area, and the main pollutants were 1,2-dichloroethane (1,2-DCA), vinyl chloride (VCE), chloroform, cis-1,2-dichloroethylene, 1,1-dichloroethane, and chloroethane. The concentrations of CAH decreased in a fluctuation pattern, and the downward trends were obvious. The concentrations of VCE in MW2-1 and MW2-5, and 1,2-DCA in MW2-1 and MW2-2 were higher than the corresponding risk control value. The concentrations of CAH at other monitoring wells were lower than the corresponding risk control value. According to evaluation results of microbial degradation ability calculated by typical geochemical parameters, the microbial degradation ability was insufficient in most areas of the contaminated sites. However, the microbial degradation ability was significant in these monitoring well with relatively high CAH concentrations. The attenuation rates of CAH in groundwater ranged from 0.0001 to 0.0040 d-1. As a result, the remediation time required for VCE and 1,2-DCA to reach the corresponding risk control value through natural attenuation will take about 7.2 and 5.4 years, respectively. It is suggested that other remediation technologies may need to be combined to strengthen the natural attenuation process. The boundaries of high-concentration polluted areas were focused by continuous monitoring for 4 years, providing basic data for the next stage of active remediation. This study will provide technical support and scientific guidance for the application of MNA technology to remediate CAH contaminated sites in China.