基于生命周期评价的焦化污染土壤淋洗技术环境影响研究

Study on Environmental Impact of Leaching Technology of Coking Contaminated Soil Based on Life Cycle Assessment

为综合评估土壤淋洗修复技术的环境影响,针对焦化场地多环芳烃(PAHs)污染土壤,利用绿色生物表面活性剂——鼠李糖脂及黄腐酸进行溶液及泡沫模拟淋洗修复,并应用全生命周期评价(LCA)方法对淋洗修复全过程进行评价。结果表明:在相同污染物去除效果的前提下,溶液及泡沫两种淋洗方式的环境影响由大到小排序均为:不可再生资源消耗(ADP)>全球变暖效应(GWP)>人体毒性效应(HTP)>富营养化效应(EP)>酸化效应(AP)>光化学臭氧形成潜值(POCP)。在使用不同淋洗剂时,均表现为溶液淋洗的环境影响大于泡沫淋洗。淋洗不同阶段的环境影响具有明显差异,淋洗后处理阶段75%的环境影响指标占全程的影响比例均超过60%。因此,绿色表面淋洗剂的优选及对淋洗后处理阶段的改进有助于加强淋洗修复技术的环境友好性。

In order to comprehensively evaluate the environmental impact of soil leaching remediation technology,the green biosurfactants rhamnolipid and fulvic acid were used to simulate the leaching remediation of soil polluted by polycyclic aromatic hydrocarbons(PAHs)in solution and foam,and the whole process of leaching remediation was evaluated by the method of life cycle assessment(LCA).The results showed that under two leaching methods,the level of environmental impact from high to low was Abiotic Resource Depletion Potentials(ADP)>Global Warming Potential(GWP)>Human Toxicity Potential(HTP)>Eutrophication Potential(EP)>Acidification Potential(AP)>Photochemical Ozone Creation Potential(POCP).Under the different biosurfactants treatment,both rhamnolipid and fulvic acid leaching showed that the environmental impact of solution leaching was greater than foam leaching.The environmental impact of the post-leaching treatment stage was higher than the soil leaching stage and 75%of the environmental impact indicators from it account for more than 60%of the total impact.Therefore,the optimization of biosurfactants and the improvement of the post-leaching treatment stage can strengthen the environmental friendliness and sustainable development of the leaching remediation technology.