固体废物填埋场甲烷气生成与减少途径

Generating and Reducing of Methane from Solid Waste Landfill Site

填埋场为甲烷菌产生甲烷提供了厌氧条件和富有机质的环境。有资料表明,全球填埋场甲烷释放量估计值为9×10~6～70×10~6t/a。据研究表明,受湿度、温度、pH和营养成分诸多变量的影响,填埋废物的最大甲烷产量约为0.06～0.13m^3/kg(干重)。在一定区域,甲烷年产生速率变化可以超过一个数量级。填埋场甲烷的归宿有3个:被覆盖土中的甲烷氧化菌氧化为CO_2后释放;通过填埋场覆盖上直接释放到大气中;燃烧利用而产生CO_2。因此,有必要采取减少CH_4排放的措施。

Landfill of solid waste provides anaerobic condition and rich organic matter environment for methane generation by methanogenic bacteria. The available information showed that worldwide landfill methane emissions were 9×106 to 70×106 t/a. Based on previous studies, maximum methane yields from landfill refuse are about 0.06 to 0.13m3/(dry)kg refuse, depending on several environmental variations, such as moisture, temperature, pH and nutrients. Annual rate of methane production may be varied by more than 10 times within a given site.Fates for landfill methane were including: oxidation of methanotrophs in cover soil, with emission of CO2; direct emission to atmosphere through landfill cover soil; and recovery of methane followed by combustion to produce CO2.Therefore, measures should be required to drop methane emission from landfill.