【正文】 填埋場微生物的分解，氣候條件，垃圾特性和垃圾填 埋作業(yè)當(dāng)中的許多因素造成氣體和垃圾填埋場滲濾液的產(chǎn)生。 （ 3）混合動力系統(tǒng)是幾個防滲相結(jié)合組成的一個活躍或 被動系統(tǒng)（ Alzaydi，1980）。在美國，該氣體為代表的能源能夠滿足能源需求總數(shù)的 1％的或 5%的天然氣利用。據(jù) 估計，通過垃圾填埋場的甲烷擴散通量涵蓋介于 390和 1200 kg/m2/年。一旦達到在堆填區(qū)底部或不透水層，滲濾液 就要 導(dǎo)排到指定的地方 ， 否則會 透過 填埋地基，進入地下。在填埋氣治理措施不完善的情況下，填埋氣體可向上遷移，穿過填埋場覆蓋層，由于濃度梯度和壓力梯度，逃逸到大氣中。除了潛在的健康危害，這些問題包括火災(zāi) 、 爆炸 、 植被破壞 、 臭氣 、 垃圾填埋場沉降 、地下水污染 、 空氣污染和全球變暖 等 。水溶性化合物在安置過程中或者在化學(xué)和生物過程中遇到的垃圾。高分子脂肪酸氧化為中間副產(chǎn)品和氫氣。二氧化碳 的 產(chǎn)生近似等同于消耗氧氣。因此，堆填將繼續(xù) 成為最具吸引力的固體廢物處置的路線。 (2) passive venting consisting of a trench installed beyond the land?ll boundary and back?lled with coarse material (. gravel) to create a zone of high permeability which would be preferentially used by the gas。 Goleuke, 1980。 Sheppard et al., 1982). The upper range is questionable, particularly when pared with methane yield data from actual land?lls with a recovery system. The economic feasibility of land?ll gas recovery, processing, and utilization have indeed been demonstrated and reported by many investigators at sites under di?erent climatic conditions (Boyle, 1976。 Harkov et al., 1985。 Reinhard et al., 1984。 Gilman et al., 1981, 1982, 1985。 Barlaz et al.,1989c). Under a stabilized methanogenic condition which is the stage of interest from a bene?cial recovery perspective, methane and carbon dioxide are by far the two principal ponents of land?ll gas and form more than 90% of the total gas and oxygen are normally present in small quantities primarily as a result of air entrapment during waste deposition, atmospheric air di?usion through the land?ll cover especially in the near surface layers, or air intrusion from negative land?ll pressure when land?ll gas is extracted. 3. Leachate Formation Mechanisms Leachate formation is the result of the removal of soluble pounds by the nonuniform and intermittent percolation of water through the refuse mass. Soluble pounds aregenerally encountered in the refuse at emplacement or are formed in chemical and biological processes. The sources of percolating water are primarily the precipitation,irrigation, and run o? which cause in?ltration through the land?ll cover。 Wolfe, 1979。 Environmental Impacts of Solid Waste Landfilling Abstract:Inevitable consequences of the practice of solid waste disposal in landfills are gas and leachate generation due primarily to microbial deposition, climatic conditions, refuse characteristics and landfilling operations. The migration of gas and leachate away from the landfill boundaries and their release into the surrounding environment present serious environmental concerns at both existing and new facilities. Besides potential health hazards, these concerns include, and are not limited to, fires and explosions, vegetation damage, unpleasant odors, landfill settlement, ground water pollution, air pollution and global warming. This paper presents an overview of gas and leachate formation mechanisms in landfills and their adverse environmental impacts, and describes control methods to eliminate or minimize these impacts. Keywords: landfill, solid waste disposal, biodegradation, gas and leachate generation, environmental impacts, control methods Solid waste disposal in landfills remains the most economic form of disposal in the vast majority of cases (Thompson and Zandi, 1975。 McCarty 1981。 ground water intrusion, and to a lesser extent, the initial refusemoisture deposition due to microbial activity may also contribute to leachate formation but in smaller amounts. The quantity of leachate generated is sitespeci?c and a function of water availability and weather conditions as well as the characteristics of the refuse, the land?ll surface, and underlying soil. The quality of land?ll leachate is highly dependent upon the stage of fermentation in the land?ll, waste position, operational procedures, and codisposal of industrial wastes (Hoeks and Harmsen, 1980。 Arthur et al.,1985). The damage occurs primarily due to oxygen de?ciency in the root zone resulting from a direct displacement of oxygen by land?ll gas. In the absence of a gas control measure, land?ll gas can migrate upward due to concentration and pressure gradients, and escape into the atmosphere by venting through the land?ll cover. During this process, oxygen is displaced and plant roots are exposed to high concentrations of methane and carbon dioxide, the two major constituents of land?ll gas. The lack of oxygen causes the death of plants of asphyxia. . Unpleasants Odors are mainly the result of the presence of small concentrations of odorous constituents (esters, hydrogen sul?de, organosulphurs, alkylbenzenes, limonene and other hydrocarbons) in land?ll gas emitted into the atmosphere (Young and Parker,1983, 1984). The odorous nature of land?ll gas may vary widely from relatively sweet to bitter and acrid depending on the concentration of the odorous constituents