Environmental Risk Control of the Waste Disposal in Landfills

本研究的主要目的是建立一系列策略，以控制垃圾填埋场从建设到废止或填埋利用期间的环境风险。主要研究成果如下：1.通过室内实验分析了污染物在地下的去向和运移规律。重金属和挥发性有机化合物(特别是稠密的非水相液体)是本研究的主要关注对象。主要通过实验室批淋洗和柱状淋洗试验研究了微生物活动对填埋场重金属迁移的影响及其与底层粘土层的相互作用。当微生物活动导致低ORP条件时，重金属的迁移性降低。此外，粘土层的酸缓冲能力对重金属的固定有很大的贡献。2.废弃污泥作为垃圾填埋层的性能是评价…并对其保水性能和透气性能进行了一系列的室内实验。从水量平衡和垃圾填埋气收集的角度对其适用性进行了数值分析。3.对土工合成粘土衬垫(GCL)和土工膜等土工合成材料作为填埋场衬砌材料的化学相容性进行了评价，以验证其原位水力屏障性能。特别是，考虑到GCL预水化的影响，研究了渗透了无机溶液或垃圾渗滤液的GCL的水力传导值。通过环境风险评估的案例研究，验证了非法倾倒含有二恶英和多氯联苯的废物的补救行动在减少人类健康风险方面的有效性。在研究成果的基础上，提出了垃圾处理的环境风险控制方案，包括垃圾填埋场废止后的岩土工程利用。较少

The main objective of this study is to establish a series of strategies for controlling the environmental risk related to waste disposal in landfill site during the period from its construction to abolition or landfill utilization. The main results obtained in this study can be summarized as follows :1.Fate and transport of pollutants in subsurface were analyzed by the laboratory experiments. Heavy metals and volatile organic compounds (particularly Dense Non-Aqueous Phase Liquids) are of main concern in this research. Effect of microbial activities on the mobility of heavy metals in land-fills and their interactions with bottom clay layer were mainly examined through laboratory batch and column leaching tests. Mobility of heavy metals is reduced when low ORP condition is induced by the microbial activities. In addition, acid buffering capacity of clay layer is proved to greatly contribute to the immobility of heavy metals.2.Performance of waste sludge as landfill cover layer was evalu … More ated through a series of laboratory experiments on its water retention property and air permeability. Numerical analyses were conducted to verify its applicability from the viewpoints of water balance and landfillgas collection.3.Chemical compatibilities of geosynthetics used as landfill lining materials, such as geosynthetic clay liner(GCL) and geomembrane, were evaluated to verify their in-situ hydraulic barrier performance. Particularly, hydraulic conductivity values of GCL permeated with inorganic solutions or landfill leachate were investigated considering the effect of prehydration of GCL.4.A case study of environmental risk assessment is conducted to verify the effectiveness of the remedial action for the illegal dumping of wastes containing dioxins and PCBs with regard to reduction of human health risks. The scheme for environmental risk control of waste disposal, including the geotechnical utilization of landfill after its abolition, is proposed based on the achievements of this study. Less