呼吸型填埋场覆盖层技术研究Ⅱ：呼吸型覆盖层的甲烷氧化性能研究

Development of a breathing landfill biocover technique II:Study on the methane oxidation capability

基于前期研究构建的热动力自充氧装置,研究了模拟呼吸型自充氧覆盖层(2.4m×0.85m×3.6m,长×宽×高)对甲烷氧化性能的影响.结果表明,在垃圾快速降解期内,40cm厚自充氧覆盖层中的O2含量始终保持在15%以上,释放到外界的填埋气中CH4含量在检出限以下,与传统覆盖层技术相比,CH4含量最大可削减76.5%.通气管路的对比研究进一步表明,自充氧覆盖层技术克服了传统覆盖层内部O2不足的瓶颈,充氧速率的增加在一定程度上有助于CH4转化.利用热动力改变覆盖层内的气体组成结构,提高了O2含量和好氧微生物的活性,进而增强CH4转化效果.该技术为中小型填埋场控制温室气体排放提供了新的途径和思路.

Based on the passive air venting system developed in previous research,an upscaled simulated system（2.4 m×0.85 m×3.6 m） combined the breathing biocover with semi-aerobic landfill was constructed.Its effect on methane oxidation capability was investigated.The results showed that the lowest O2 level kept more than 15% in the whole biocover layer（40 cm） during the fast degradation phase of waste.Correspondingly,CH4 in the surface area of the biocover layer cannot be detected.Compared to the traditional cover layer,the highest CH4 concentration can be reduced by 76.5% with the introduction of the breathing biocover.Oxygen supply by thermal motive changed the distribution of CH4 and CO2 inside the cover layer.The study verified the hypothesis that methane emission can be reduced by enhancing activity of methanotrophs through supplying sufficient O2 in the cover layer.