|Abstract: ||摘要:許多用於處置汙染物與廢料之設備,主要用來 減少廢料與其它物質接觸之機會,而最終目地則 是在於防止地下水源之汙染.在眾多防止汙染源 擴散與移流以減少地下水源之汙染之諸設備中, 皂土截水牆是目前世界各國最廣泛使用之施工技 術,在此方法中,首先開挖一槽溝,並以皂土與水拌 合之皂土泥漿穩固槽溝壁,再回填以土壤和皂土 泥漿混合之材料,以形成一道不透水之截水牆,以 截取汙染源流.雖然皂土截水牆在汙染移流之控制上的應用,急 遽增加,然而,其並非能解決所有汙染之問題.有許 多研究顯示皂土截水牆遭遇化學物質侵襲時,會 改變其性質而增加其水力傳導度,終至減少皂土 截水牆控制汙染移流之績效.如此,就得詳細探討皂土截水牆遭受化學廢料侵襲時之穩定性,才能 確保其控制汙染移流和避免地下水源受汙染之效 用.本研究計畫,首先擬探討皂土截水牆長期抗化學 侵襲之可行性.接著研究抗各種化學侵襲之最佳 皂土截水牆施工技術與穩固方法.最後,期盼經此 研究,能夠在國內建造出較國外更能防化學侵襲 之皂土截水牆,以完全控制汙染源之移流,進而徹 底解決地下水源受汙染之嚴重問題.|
abstract:A major reason for many facilities utilized for containment and disposal of hazardous wastes is the protection of groundwater resources. Among various facilities, bentonite slurry cut-off walls have achieved wide recognition in a variety of applications as seepage barriers for the control of pollution migration and the consequent protection of groundwater resources. By this method, a trench of the desired configuration is excavated using a bentonite and water slurry to support the sides. The trench is then backfilled with a mixture of soil and bentonite slurry that forms the permanent impervious cut-off wall. Although the use of bentonite slurry cut-off walls for pollution migration control has increased rapidly the last decade, however, slurry walls are not an answer to all waste site problems. One of the limitations to the use of slurry cut-off walls is that exposure to the waste at some sites may cause increases in wall permeability, hence deteriorate wall performance. To indicate the ability of slurry walls to withstand chemical degradation over times, it is necessary to investigate the performance of the walls in the presence of chemical contaminants. In this study, the feasibility of soil-bentonite slurry wall against chemical attack is investigated. Effort is also made to optimize a soil-bentonite construction technique. From test results, it is found that by adding flyash stabilizer, soil-bentonite slurry walls could be stabilized against chemical attacks.