| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 91 === Although the primary fashion of waste disposal is by incinerating at present, the ultimate and must-exist method is still by disposing into sanitary landfill. The main design of landfill sites is to isolate pollutants; the key to its success is the leachate management. Therefore, this article will probe into the method of leachate quantity management from the waste minimization viewpoint and focus on the zoning landfill and leachate recirculation in order to control and reduce it effectively.
Strategy of the zoning landfill divides into three categories: the working section, the incomplete section and the complete section. The incomplete section yet buries any wastes and the complete section has done the covering due to rainfall, thus the surface run-off is considered unpolluted and drained to the ditches through the temporary conduit or water pumps.
Strategy of the zoning landfill is quite beneficial to the reduction of leachate particularly when the area of landfill is larger. It will drain away the surface run-off of the unpolluted area through zoning landfill to avoid heavy burden for the sewage treatment system. The larger the section of landfill site is, the better the effectiveness of leachate reduces; relatively the smaller the working section of landfill site is, the lesser the leachate produces. Request of the minimum area of the working section must be considered deliberately during planning in order to fulfill the entry of machines, tools and staffs.
Principle of the leachate recirculation is transporting leachate from collection tank to landfill site through the recirculation pump, recirculation pipe and infiltration pipe. The function of gravel’s water scattering will implant uniformly to the waste layer from the infiltration pipes and ditches.
Strategy of the leachate recirculation is beneficial to both the leachate reduction and the improvement of leachate water quality; this article mainly focuses on the effectiveness of leachate reduction as a result of the leachate quantity. Due to evaporation, leachate reduces after the recirculation; result of the reduction will be different based on the climatic condition in different region. In addition, the effect of water absorption of the waste layer will be nearly saturated after the leachate recirculation. Thus the rainfall will not be able to infiltrate to the saturated layer that leads to the increase of surface run-off.
This article analyzes the B-grade landfill site of Yuan-Shan Technology Co., Inc as an illustration in the end. Yuan-Shan’s analytical results have succeeded in terms of economic profit no matter on the zoning landfill or the leachate recirculation. However, it must establish the management process and system on landfill sites in order to perfectly perform the concept of leachate recirculation on practical fields.
|
|---|
