外文翻譯----固體廢物填埋對環(huán)境的影響

1、<p>　　Environmental Impacts of Solid Waste Landfilling</p><p>　　Abstract:Inevitable consequences of the practice of solid waste disposal in landfills are gas and leachate generation due primarily to mic

2、robial decomposition, 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

3、 serious environmental concerns at both existing and new facilities. Besides potential health hazards, these concerns include, and are not lim</p><p>　　Keywords: landfill, solid waste disposal, biodegradatio

4、n, gas and leachate generation, environmental impacts, control methods</p><p>　　1.Introduction </p><p>　　Solid waste disposal in landfills remains the most economic form of disposal in the vast

5、 majority of cases (Thompson and Zandi, 1975; Rushbrook, 1983; Carr and Cossu, 1990). Therefore, landfills will continue to be the most attractive disposal route for solid waste. Indeed, depending on location, up to 95%

6、of solid waste generated world- wide is currently disposed of in landfills (Bingemer and Crutzen, 1987; Cossu, 1989; Nozhevnikova et al., 1992; Gendebien et al., 1992). Alternatives to landfil</p><p>　　Most

7、organic materials are biodegredable and can be broken down into simpler compounds by aerobic and anaerobic microorganisms, leading to the formation of gas and leachate. The following sections provide an overview of the m

8、echanisms of gas and leachate formation in land?lls, their environmental impacts, and appropriate control methods to eliminate or minimize these impacts.</p><p>　　2. Land?ll Gas Formation Mechanisms</p>

9、;<p>　　At the time of waste deposition in a land?ll, oxygen is present in the void space, giving rise to aerobic decomposition during which biodegradable organic materials react quickly with oxygen to form carbon

10、dioxide, water, and other by-products (e.g. bacterialcells). Carbon dioxide is produced in approximate molar equivalents to the oxygenconsumed. Oxygen depletion within the land?ll marks the onset of the anaerobic decompo

11、siton phase. Although a land?ll ecosystem undergoes an initial short aerob</p><p>　　Much of what is known or assumed concerning anaerobic processes in land?lls has primarily come from work with anaerobic dig

12、esters. Microbial populations in both environments appear to be similar however, the major di?erence is that the substrates may vary in their relative content of fat, protein, and carbohydrates, and conversely to land?

13、lls, the environment in anaerobic digesters is well controlled and often under optimal conditions.</p><p>　　Investigators have recognized several major steps to describe the anaerobic de-composition phase du

14、ring which organic materials are converted to methane and carbon dioxide (Alexander, 1971; Zehnder, 1978; Wolfe, 1979; McCarty 1981; Zehnder et al.,1982; Mosey, 1983; Archer and Robertson, 1986; Balba, 1987). These steps

15、 are highly inter-dependent and include hydrolysis, acidogenesis, acetogenesis, and methanogenesis(Figure 1).</p><p>　　Generally, the breakdown of organic matter in anaerobic ecosystems proceeds</p>&

16、lt;p>　　sequentially from the complex to the simple starting with the hydrolysis of complex particulate matter to simpler polymers like proteins, carbohydrates and lipids which are further hydrolyzed to yield biomonome

17、rs like amino acids, sugars, and high molecular fatty acids. Amino acids and sugars are converted into either intermediate by-products (e.g. propionic, butyric and other volatile acids) or directly fermented to acetic ac

18、id. High molecular fatty acids are oxidized to intermediate by-product</p><p>　　the lack of hydrogen which is consumed by sulfate reducers (Kasali, 1986).</p><p>　　Qualitatively, land?ll gas is

19、highly dependent on the decomposition stage within the land?ll (Rovers and Farquhar, 1973; Rees, 1980; Pohland et al., 1983; Barlaz et al.,1989c). Under a stabilized methanogenic condition which is the stage of interest

20、from a bene?cial recovery perspective, methane and carbon dioxide are by far the two principal components of land?ll gas and form more than 90% of the total gas generated.Nitrogen and oxygen are normally present in small

21、 quantities primarily as a res</p><p>　　3. Leachate Formation Mechanisms</p><p>　　Leachate formation is the result of the removal of soluble compounds by the non-uniform and intermittent percola

22、tion of water through the refuse mass. Soluble compounds aregenerally encountered in the refuse at emplacement or are formed in chemical and biological processes. The sources of percolating water are primarily the precip

23、itation,irrigation, and run o? which cause in?ltration through the land?ll cover; ground water intrusion, and to a lesser extent, the initial refusemoisture content.Ref</p><p>　　The quality of land?ll leacha

24、te is highly dependent upon the stage of fermentation in the land?ll, waste composition, operational procedures, and co-disposal of industrial wastes (Hoeks and Harmsen, 1980; Parker and Williams, 1981; Harmen, 1983; Poh

25、land et al., 1983). Many chemicals (e.g. metals, aliphatics, acyclics, terpenes, and aromatics) have been detected in land?ll leachate from domestic, commercial, industrial, and co-disposal sites. </p><p>　　

26、4. Environmental Impacts</p><p>　　Historically, land?lls were initiated largely as a result of a need to protect the environment and society from adverse impacts of alternative methods of refuse disposal suc

27、h as open-air burning, open-pit dumping, and ocean dumping (Senior, 1990). Although land?lls eliminated some impacts of old practices, new ones arose, primarily due to gas and leachate formation. Besides potential health

28、 hazards, these concerns include ?res and explosions, vegetation damage, unpleasant odors, land?ll settleme</p><p>　　4.1 Fire and Explosion Hazards? ??? ????????? ?</p><p>　　Although land?ll gas

29、 rich in methane provides an energy recovery opportunity, it has often been considered to be a liability because of its ?ammability, its ability to form explosive mixtures with air, and its tendency to migrate away from

30、the land?ll boundaries by di?usion and advection. Di?usion is the physical process that causes a gas to seek a uniform concentration throughout the land?ll volume, hence the gas moves from areas of higher to areas of low

31、er concentration. Advection results from</p><p>　　4.2.Vegetation Damage????????? ?????????????</p><p>　　At closure, many land?ll sites are converted to parks, golf courses, agricultural ?elds, a

32、nd in some cases, commercial developments. Vegetation damage at or nearby to such sites is well documented in the literature (Flower et al., 1977, 1981; Leone et al., 1977; Leone and Flower, 1982; Gilman, 1980; Gilman et

33、 al., 1981, 1982, 1985; 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 absenc</p><p>　　4.3. Un

34、pleasants Odors???????? ?????</p><p>　　Odors are mainly the result of the presence of small concentrations of odorous constituents (esters, hydrogen sul?de, organosulphurs, alkylbenzenes, limonene and other

35、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 od

36、orous constituents within the gas. These concentrations will vary with waste composition and age, decomposition </p><p>　　4.4 Ground Water Pollution ?????? ????? ?????????</p><p>　　Leachate occu

37、rrence is by far the most signi?cant threat to ground water. Once it reaches the bottom of the land?ll or an impermeable layer within the land?ll, leachate either travels laterally to a point where it discharges to the g

38、round’s surface as a seep, or it will move through the base of the land?ll and into the subsurface formations. Depending upon the nature of these formations and in the absence of a leachate collection system, leachate ha

39、s reportedly been associated with the contamina</p><p>　　4.5. Air Pollution?? ?????????</p><p>　　Although methane and carbon dioxide are the two major components of the gas emitted from land?lls

40、, there is evidence that this gas contains numerous other constituents in trace amounts signi?cant enough to cause environmental and health concerns(Lytwynyshyn et al., 1982; Young and Parker, 1983; Karimi, 1983; Gianti

41、et al., 1984; Harkov et al., 1985; Todd and Propper, 1985; Young and Heasman, 1985; Wood and Porter, 1986; Rettenberg, 1984, 1987). Potential emissions of Volatile Organic Compounds (</p><p>　　/day (US EPA,

42、1989).</p><p>　　4.6 Global Warming. ?????? ???????</p><p>　　Atmospheric gas emission rates through a land?ll cover have been measured by several investigators. During dry soil conditions at a se

43、mi-arid land?ll site, Bogner et al. (1989) indicated that methane and carbon dioxide ?uxes may be as high as 630 and 950 kg/ m2/yr, respectively. Using ?ux box measurements, Lytwynyshyn et al. (1982) and Kunz and Lu (197

44、9, 1980), estimated that methane di?usion ?ux through land?ll covers ranged between 390 and 1200 kg/m2/yr. These measurements are likely to undere</p><p>　　5. Land?ll gas and leachate control</p><

45、p>　　Land?ll gas control measures are essential in order to eliminate or minimize its associated adverse environmental impacts. In most cases the installation of a gas recovery, collection and treatment system will ass

46、ist in preventing gas migration away from the land?ll boundaries or gas emissions through the land?ll surface. Indeed many of the early gas recovery projects were developed as a consequence of, or as an adjunct to, exist

47、ing gas migration control schemes. When land?ll gas is recovered ap</p><p>　　The economic feasibility of land?ll gas recovery, processing, and utilization have indeed been demonstrated and reported by many i

48、nvestigators at sites under di?erent climatic conditions (Boyle, 1976; Lockman, 1979; Kaszynski et al., 1981; EMCON, 1983; Mouton, 1984; Wiqwist, 1986; Gendebien et al., 1992). New land?lls can be designed to prevent lan

49、d?ll gas accumulation even if no productive use of the gas is planned. Land?ll gas control systems have been well documented in engineering practice (</p><p>　　(1) the installation of impermeable barriers be

50、fore site operations to secure the perimeter of the land?ll (cement walls, clay trenches, impervious liner materials such as plastics, rubber, asphalt, polyvinyl chloride, high density polyethylene, etc.); </p>&l

51、t;p>　　(2) passive venting</p><p>　　consisting of a trench installed beyond the land?ll boundary and back?lled with coarse material (e.g. gravel) to create a zone of high permeability which would be prefer

52、entially used by the gas; (3) a hybrid system consisting of any combination of impermeable barriers and an active or passive system (Alzaydi, 1980). Injection of lime slurry and ?y ash has also been reported to control m

53、ethane formation and stabilize land?lls by inhibiting methanogenesis and stopping land?ll gas generation (Kinma</p><p>　　Leachate composition can be controlled to a limited extent by close monitoring and sor

54、ting of land?ll waste. However, decomposition byproducts dissolved in in?ltrating water will result in a leachate with elevated concentrations of numerous hazardous chemicals. Leachate treatment is often necessary to red

55、uce these concentrations to levels that meet regulatory requirements. Most biological, physical and chemical processes used for the treatment of industrial wastewater have been tested for treatm</p><p>　　6.

56、Summary and conclusions</p><p>　　Gas and leachate generation are inevitable consequences of the practice of waste disposal in land?lls.Microbial decomposition, climatic conditions, refuse characteristics and

57、 land?lling operations are amongst the many factors contributing the gas and leachate generation at land?ll sites. The migration of gas and leachate away from the land?ll boundaries and their release into the surrounding

58、 environment present serious environmental concerns at both existing and new facilities including potentia</p><p>　　7．References</p><p>　　Abriola, L. and Pinder, G. F. (1985). A multiphase appro

59、ach to the modeling of porous media contamination by organic compounds, 1. equation development; 2. numerical simulation. Water Resources Research, 21,1–26.</p><p>　　Adamse, A. D., Hoeks, J., DeBont, J. A.

60、 M. and Kessel, J. F. (1972). Microbial activities in soil near natural gas leaks. Archiv fur Microbiologie, 83, 32–51.</p><p>　　Albaiges, J., Casado, F. and Ventura, F. (1986). Organic indicators of groundw

61、ater pollution by a sanitary land?ll. Water Research, 20, 1153–1159.</p><p>　　Alexnder, M. (1971). Microbial ecology. New York: John Wiley & Sons, Inc. Alzaydi,A. A. (1980). Land?ll gasmigration and cont

62、rol systems. Its applications and limitations. In Life Cycle</p><p>　　Problems in Environmental Technology, Proceedings of the 26th Annual Technical Meeting, Philadelphia, Pennsylvania, 337–341.</p>&

63、lt;p>　　Alpern, R. (1973). Decomposition rates of garbage in existing Los Angeles land?lls. M.S. Thesis, California State University, Long Beach, California.</p><p>　　Anderson, D. R. and Callinan, J. P. (1

64、970). Gas generation and movement in land?lls. In Industrial Solid</p><p>　　Wastes Management, Proceedings of the National Conference, Houston, Texas, 311–316.</p><p>　　Archer, D. B. and Roberts

65、on, J. A. (1986). The fundamentals of land?ll microbiology. In Energy from Land?ll Gas, (J. R. Emberton and R. F. Emberton, eds), Solihull, U.K., pp. 116–122.</p><p>　　Arigala, S. G., Tsotsis, T. T., Webster

66、, I. A., Yortsos, Y. C. and Kattapuram, J. J. (1995). Gas generation, transport, and extraction in land?lls. Journal of Environmental Engineering, 121, 33–44.</p><p>　　Arthur, J. J., Leone, I. A. and Flower,

67、 F. B. (1985). The response of tomato plants to simulated land?ll gas mixtures. Journal of Environmental Science and Health, 20, 913–925.</p><p>　　Augenstein, D. C., Cooney, C. L., Wise, D. L. and Wentworth,

68、 R. L. (1976). Fuel gas recovery from controlled land?lling of municipal wastes. Resources Recovery and Conservation, 2, 103–107.</p><p>　　Augenstein, D. C. (1990). Greenhouse e?ect contributions of US land?

69、ll methane. In Land?ll Gas: Energyand Environment, (Richards, G. E. and Alston, Y. R., eds), pp. 615–645.</p><p>　　Baehr, A. L. (1987). Selective transport of hydrocarbons in the unsaturated zone due to aque

70、ous and vapor phase partitioning. Water Resources Research, 23, 1926–1938.</p><p>　　固體廢物填埋對環(huán)境的影響</p><p>　　摘要：由于氣象條件的差異、填埋垃圾的特性、填埋場類型的不同，固體廢物填埋處置中由微生物分解而產(chǎn)生的氣體和滲濾液對環(huán)境產(chǎn)生了很大的影響。目前，填埋氣體的遷移和滲濾液向填埋場邊界外

71、滲以及它們對周圍環(huán)境的排放產(chǎn)生了嚴重的環(huán)境問題。除了包括一些潛在的健康危害外，這些問題還可能引發(fā)包括：火災，爆炸，破壞植被，臭氣，垃圾填埋場不均勻沉降，地下水污染，空氣污染和全球變暖等問題。本文對填埋氣體，堆填區(qū)滲濾液的形成機理和對環(huán)境造成不良影響做了概述，并介紹了消除或減少這些影響的方法。</p><p>　　關鍵詞：垃圾填埋場； 固體廢物處理； 生物降解； 氣體和滲濾液的產(chǎn)生； 對環(huán)境的影響； 控制方法<

72、;/p><p><b>　　1．引言</b></p><p>　　在絕大多數(shù)情況下，垃圾填埋仍是最經(jīng)濟的固體廢物處置方式。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。事實上，根據(jù)相關資料，當今世界上有 95％的固體廢物產(chǎn)生是通過填埋，這種方法處置的垃圾填埋被稱為是減量化工藝，因為它們產(chǎn)生的廢物組分（比如燃燒過程產(chǎn)生的飛灰能產(chǎn)生二次污染），其最終必須進行填埋。填埋不

73、僅僅局限對城市生活固體廢物的處置，同時也包括大多數(shù)其他工業(yè)垃圾固體廢棄物。例如，近80在美國產(chǎn)生的危險廢物都是填埋處置的。固體廢物的成分與社會經(jīng)濟條件，地域等條件有關，差異極大。</p><p>　　多數(shù)有機材料可生物降解，能在好氧和厭氧微生物的作用下降解為簡單化合物，這就產(chǎn)生氣體和滲濾液的形成。以下各節(jié)概述了氣體和滲濾液在填埋場的形成機制，對環(huán)境的影響，以及適當?shù)目刂品椒?，以消除或減少這些影響。</p&g

74、t;<p>　　2．填埋氣體的形成機理</p><p>　　在填埋廢物分解的過程中，產(chǎn)生氧氣，導致可降解有機物迅速與氧氣發(fā)生反應，形成形成二氧化碳，水和其他的產(chǎn)物。二氧化碳的產(chǎn)生近似等同于消耗氧氣。在氧氣耗盡就標志著填埋場厭氧分解來的階段的開始。雖然經(jīng)歷了一個垃圾填埋場生態(tài)系統(tǒng)短期好氧分解的初步階段，隨后的厭氧階段在持續(xù)的時間和氣體形成的角度看是主要的反應階段。</p><p&g

75、t;　　大部分已知的或假定的有關堆填區(qū)的厭氧過程中主要的是厭氧消化。在兩種環(huán)境中微生物種群似乎是類似，主要區(qū)別在于，他們可能會有不同組分的脂肪，蛋白質的相對含量，碳水化合物，并反過來作用于填埋垃圾，在厭氧消化環(huán)境中可以很好控制，而且往往是最佳條件。</p><p>　　研究人員在有機材料轉換為甲烷和二氧化碳的過程中已經(jīng)發(fā)現(xiàn)了很多重大步驟來描述厭氧的階段，這些步驟是高度相互依存的，包括水解，酸化，酸形成期和甲烷形成

76、期。</p><p>　　一般而言，有機質在厭氧生態(tài)系統(tǒng)的分解按順序從復雜到稍微復雜的顆粒物質水解開始到更復雜的高分子蛋白質，碳水化合物和脂肪，進一步水解產(chǎn)生如氨基酸，糖，高分子脂肪酸。氨基酸和糖轉換成副產(chǎn)品如丙酸，丁酸等揮發(fā)性酸（丙酸，丁酸等揮發(fā)性酸）或直接發(fā)酵形成醋酸。高分子脂肪酸氧化為中間副產(chǎn)品和氫氣。醋酸分解形成甲烷和二氧化碳。甲烷也是經(jīng)碳和氫反應形成的。在垃圾填埋環(huán)境下，從后者往往是受到限制的。因為缺少

77、酸產(chǎn)生時期的還原劑氫。同樣，填埋氣體于堆填區(qū)分解階段有很大的關系。從有利于復蘇的角度來看，在一個穩(wěn)定的產(chǎn)甲烷條件是最理想的階段，甲烷和二氧化碳是目前的兩個垃圾填埋氣體的主要成分，占總填埋氣體的90%，氮氣和氧氣，產(chǎn)生量很少，目前主要是因為在空氣中沉積廢物誘捕，通過填埋場大氣擴散，特別是在近表面層，或在空氣負填埋垃圾填埋氣體的壓力入侵時被提取。</p><p><b>　　3．滲濾液形成機制</b&

78、gt;</p><p>　　滲濾液形成是可溶性物質在垃圾中以水的形式不均勻和間歇滲透的結果。水溶性化合物在安置過程中或者在化學和生物過程中遇到的垃圾。滲濾水的來源主要是降水，灌溉，地表徑流，地下水入侵，還有很少一部分垃圾分解而形成的水分。由于微生物的活動也可能有助于滲濾液形成，但是量很少。滲濾液產(chǎn)生量的決定因素有地形特點、地下水、氣象條件、垃圾的特點、垃圾填埋場表面和底層土壤。 </p><p

79、>　　垃圾填埋場滲濾液的質量是與垃圾填埋發(fā)酵階段、垃圾組份、填埋類型、工業(yè)固體廢物的處置方式等密切相關的。已被發(fā)現(xiàn)在垃圾滲濾液中有許多來源于住宅、商業(yè)、工業(yè)和共同處置場所的化學物質（如金屬，脂肪族化合物，烯烴和芳烴）。</p><p><b>　　4．環(huán)境影響</b></p><p>　　從歷史上看，垃圾填埋的實施，主要是為了保護環(huán)境和社會，減輕其他垃圾處理方法

80、的不利影響，例如露天焚燒，露天傾倒和海洋傾倒。雖然堆填法消除了一些舊的影響，但新的問題隨之出現(xiàn)了，主要是填埋氣體和滲濾液的形成。除了潛在的健康危害，這些問題包括火災、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。</p><p>　　4．1 火災和爆炸危險</p><p>　　雖然垃圾填埋氣甲烷回收是能源恢復的一個機會，它往往被認為是不利的，由于其易燃性，它能與空

81、氣形成爆炸性混合物，其有水平和垂直遷移的傾向而擴散到堆填區(qū)邊界以外。擴散是物理過程，是氣體從高濃度向低濃度擴散，使填埋氣在整個整個填埋區(qū)內的濃度相同。從壓力對流講，從高壓力區(qū)向低壓區(qū)遷移。擴散和對流率主要取決于物理性質和填埋氣體形成量、垃圾滲透率、內部堆填區(qū)溫度、周圍土壤含水量和大氣壓力的變化。</p><p><b>　　4．2植被破壞?</b></p><p>　

82、　在封場以后，許多垃圾填埋場被作為公園、高爾夫球場、農業(yè)等用地，以及在某些情況下，變成商業(yè)中心。植被或附近的這些遺跡受到破壞是有據(jù)可查的。損害發(fā)生主要是由于填埋氣體對植物根部氧氣的直接替換而導致的缺氧。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。在這個過程中，氧散失，植物根系接觸到垃圾填埋氣體主要成分是高濃度甲烷和二氧化碳，由于缺氧會導致植物窒息死亡。</p>

83、<p>　　4.3臭氣味?????????????</p><p>　　氣味，主要是將（在垃圾填埋氣體的酯，硫化氫，有機物，烷基苯，檸檬烯</p><p>　　和其他碳氫化合物，）排放到空氣。對垃圾填埋氣體的性質應該是不同氣味或苦或甜或酸取決于內部的氣味成分的濃度。這些廢物的濃度將隨組成和年齡、分解階段、氣體產(chǎn)生率、以及微生物種群內的廢物的性質，或者其他因素而不同。雖然許多有氣

84、味的化合物可能是有毒的微量元素，它們在歷史上一直被更多的認為間接的，而不是一個直接的健康危害。在何種程度上遷移到堆填區(qū)邊界以外，主要取決于天氣條件（風，溫度，壓力，濕度）。</p><p>　　4.4地下水污染????????????????????</p><p>　　滲濾液是迄今為止對地下水威脅最嚴重因素。一旦達到在堆填區(qū)底部或不透水層，滲濾液就要導排到指定的地方，否則會透過填埋地基，

85、進入地下。這取決于材料的性質，滲濾液收集系統(tǒng)的有無，過去40年的廣泛調查的結果發(fā)現(xiàn)，滲濾液與堆填區(qū)底部的含水層接觸，會導致含水層的污染。事實上，據(jù)推測，在美國，每年，對受污染的地下水，每家每戶對堆填區(qū)的市政貢獻都要超過1加侖。</p><p>　　4.5．空氣污染???????????</p><p>　　雖然甲烷和二氧化碳，是兩種來自堆填區(qū)排放的主要氣體，有證據(jù)表明，這種氣體含有微量的其

86、它組分，達到一定程度足以造成環(huán)境和健康問題。垃圾填埋場排放的揮發(fā)性有機化合物（VOCs）排放量的潛在范圍可以從4 × 10-4至1 × 10-3 kg/m2/天。</p><p>　　4.6全球變暖。 ?????????????通過對封場了的垃圾填埋場的氣體排放率的若干調查。在一個半干旱填埋場</p><p>　　干燥的土壤條件，使用通量箱測量，Bogner 指出，甲

87、烷和二氧化碳通量可高達630和950公斤高/ m2/yr。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。這些測量可能偏低，由于靠近表面的甲烷氧化菌氧化甲烷產(chǎn)生氧。雖然從控制實驗的排放率不是從垃圾填埋場實際排放量的代表，但是它們清楚地表明了氣體釋放到大氣中的傾向。</p><p>　　5．垃圾填埋氣體和滲濾液控制</p><p>　　為了消除或盡量減少其對環(huán)境

88、的不利影響，垃圾填埋氣體的控制措施是必不可少的。在大多數(shù)情況下，氣體的回收利用，收集和處理系統(tǒng)將有助于防止填埋氣運移遠離邊界和填埋氣體通過表面排放。事實上，早期的填埋氣回收項目有不少是發(fā)展成為一個舉足輕重的，或作為現(xiàn)有油氣運移控制計劃的輔助手段。填埋氣體回收適當?shù)募淄楹浚菍摿薮蟮哪茉?。?jù)估計，每年僅在美國天然氣發(fā)電潛力超過六十億立方米。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。全球每年的天然氣發(fā)電

89、潛力估計是很大的，30至4300千萬立方米，但在與有回收系統(tǒng)的實際填埋場的甲烷產(chǎn)量數(shù)據(jù)進行了對比后上限是有質疑的。</p><p>　　有很多調查員在不同氣候條件下對填埋氣體回收，處理經(jīng)濟上的可行性，利用確實證劇并報告結果。即使沒有使用的填埋氣生產(chǎn)計劃的條件下也可以設計新的堆填區(qū)，以防止垃圾填埋氣體的積累。填埋氣體控制系統(tǒng)已在工程中得到很好實踐。除了填埋氣體回收和活性氣體泵，控制措施包括：</p>

90、<p>　　（1）在填埋之前，對場地進行防滲處理。（水泥墻，粘土壕溝，如塑料，橡膠，瀝青，聚氯乙烯，高密度聚乙烯等防滲襯墊材料）; </p><p><b>　?。?）被動式排氣</b></p><p>　　在填埋場邊界設置一個盲溝，在背部用粗料如礫石（回填）創(chuàng)建一個將被氣體優(yōu)先使用的高滲透率區(qū)域。</p><p>　?。?）混合動力

91、系統(tǒng)是幾個防滲相結合組成的一個活躍或被動系統(tǒng)（Alzaydi，1980）。調查發(fā)現(xiàn)醫(yī)院垃圾和飛灰，控制甲烷形成和穩(wěn)定，抑制產(chǎn)甲烷堆填區(qū)填埋氣體。</p><p>　　通過在有限范圍內密切監(jiān)測和分析填埋垃圾可以控制滲瀝液的組成。然而，分解的副產(chǎn)品溶解于滲透水將可能與眾多的危險化學品結合，最后導致滲濾液的濃度升高。滲濾液處理通常需要減少濃度水平達到規(guī)定的監(jiān)管標準。用于工業(yè)垃圾滲濾液處理的方法常用的有生物，物理和化學法

92、。特定處理工藝選擇將取決于滲濾液質量和數(shù)量。</p><p><b>　　6．結論</b></p><p>　　氣體和滲濾污水的產(chǎn)生是廢物處理方法不可避免的后果。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)當中的許多因素造成氣體和垃圾填埋場滲濾液的產(chǎn)生。填埋氣體的遷移和滲濾污水向堆填區(qū)邊界的外移和以及對周圍環(huán)境釋放是目前新的嚴重環(huán)境問題，包括潛在的健康危害，火