通过人工构建模拟生物气藏的大型模拟生物反应器,研究模拟成藏填埋城市生活垃圾有机质厌氧降解及生物气化规律及其机理。结果表明,自然温度条件下,模拟填埋垃圾有机质降解和生物气化具有明显阶段性,与pH、ORP、温度等指标的阶段性变化存在相关性。产气阶段最佳条件包括:最适温度范围为31.0~36.0℃;最适pH范围为5.47~6.75,pH中性条件下产甲烷速率最高;ORP最适范围为-428~-541 mV,产甲烷高峰期ORP值为-519 mV,低于前人关于甲烷菌最适ORP的界定范围。每千克挥发性固体总生物气和甲烷产量分别为128.5 L和77.7 L,生物气和甲烷最大产气量分别为118.0 L/d和82.0 L/d,甲烷最大浓度为70.4%,产气高峰期与甲烷浓度高峰期同时出现。模拟成藏填埋垃圾有机质的稳定化过程具有明显的可诱导特征,关键因子的优化对有机质的降解及生物气化产生明显促进作用。
A large-scale reservoir-stimulating landfill was artificially constructed to investigate the anaerobic biodegradation, biogasification and the mechanism of organic fraction of municipal solid waste ( MSW). The re- sults sbowed that the organic matter digestion of MSW and biogasification presented obvious periodicity under room temperature conditions, and closely correlated with the phasic variation of environmental factors such as pH, ORP and temperature. The optimum conditions included: the optimum temperature range of 31. 0 36.0℃ , the optimum pH range of 5.47 - 6.75 with the best methane production rate at neutrality condition, the optimum ORP -428 ~ -541 mV, with the best methane production rate achieved at -519 mV which lower than that reported by previous researchers. Biogas and methane production were 128.5 L/( kg volatile solid) and 77.7 L/(kg volatile solid) , respectively, and the maximum production rate of biogas and methane were 118.0 L/d and 82.0 L/d, respectively, with methane concentration of 70.4%. Moreover, the peak of gas production and the peak of methane concentration appeared simultaneously. Research results proved that the stabilization of organic fraction of MSW of reservoir-stimulating landfill can be induced artificially, and the optimization of some key factors can significantly accelerate the degradation and biogasification of MSW.