Department of Environmental Engineering, Technical University of Denmark, Miljoevej, Building 113, DK-2800 Kgs. Lyngby, Denmark.
J Environ Manage. 2012 Dec 15;112:392-403. doi: 10.1016/j.jenvman.2012.08.002. Epub 2012 Sep 15.
A comparative life cycle assessment is presented for four different management options for a trichloroethene-contaminated site with a contaminant source zone located in a fractured clay till. The compared options are (i) long-term monitoring (ii) in-situ enhanced reductive dechlorination (ERD), (iii) in-situ chemical oxidation (ISCO) with permanganate and (iv) long-term monitoring combined with treatment by activated carbon at the nearby waterworks. The life cycle assessment included evaluation of both primary and secondary environmental impacts. The primary impacts are the local human toxic impacts due to contaminant leaching into groundwater that is used for drinking water, whereas the secondary environmental impacts are related to remediation activities such as monitoring, drilling and construction of wells and use of remedial amendments. The primary impacts for the compared scenarios were determined by a numerical risk assessment and remedial performance model, which predicted the contaminant mass discharge over time at a point of compliance in the aquifer and at the waterworks. The combined assessment of risk reduction and life cycle impacts showed that all management options result in higher environmental impacts than they remediate, in terms of person equivalents and assuming equal weighting of all impacts. The ERD and long-term monitoring were the scenarios with the lowest secondary life cycle impacts and are therefore the preferred alternatives. However, if activated carbon treatment at the waterworks is required in the long-term monitoring scenario, then it becomes unfavorable because of large secondary impacts. ERD is favorable due to its low secondary impacts, but only if leaching of vinyl chloride to the groundwater aquifer can be avoided. Remediation with ISCO caused the highest secondary impacts and cannot be recommended for the site.
对位于裂隙性粘土地层且污染源头位于该地层的受三氯乙烯污染场地，提出了四种不同管理方案的对比生命周期评估。所比较的方案是：（i）长期监测；（ii）原地增强还原脱氯（ERD）；（iii）原位化学氧化（ISCO）与高锰酸盐；（iv）在附近水厂进行长期监测和活性炭处理。生命周期评估包括对初级和次级环境影响的评估。初级影响是污染物淋滤到用于饮用水的地下水中导致的当地人类毒害影响，而次级环境影响则与监测、钻探和水井建设以及修复剂的使用等修复活动有关。相比方案的初级影响由数值风险评估和修复性能模型确定，该模型预测了污染物质量在含水层合规点和水厂随时间的排放。风险降低和生命周期影响的综合评估表明，在考虑所有影响的权重相等的情况下，所有管理方案的环境影响都高于修复效果。ERD 和长期监测方案具有最低的次级生命周期影响，因此是首选方案。然而，如果在长期监测方案中需要在水厂进行活性炭处理，那么由于次级影响较大，该方案就变得不利。由于其较低的次级影响，ERD 是有利的，但前提是氯乙烯不会淋滤到地下水含水层。ISCO 修复造成了最高的次级影响，因此不能推荐用于该场地。
