脱水污泥两相厌氧消化系统的启动试验

Start-Up Experiment of Two-Phase Anaerobic Digestion System for Dewatered Sludge

以北京市某再生水厂含固率(TS)为19.73%的脱水污泥为研究对象,进行了两相厌氧消化系统的启动试验。产酸相以脱水污泥为底物直接进行试验,接种少量产酸菌种;产甲烷相使用湿式启动的方法,首先在反应器中接入含固率为1.38%的产甲烷菌种,然后将酸化后的高含固率污泥作为底物投加,使产甲烷相物料含固率慢慢升高至10%以上,以避免VFAs的积累,使产甲烷相顺利启动。试验结果表明,脱水污泥的水解酸化效果良好,且反应速率较快,SCOD、VFAs、氨氮等指标的浓度在第4~6 d即达到了最大产出量的80%左右,之后反应速率下降,各项指标增长缓慢。产甲烷相湿式启动成功,物料含固率提高至10%以后,每投入1m^3污泥可产生沼气20~23m^3,日产气量最高达到3 467 mL/d,甲烷含量最高达到59.46%。

Two-phase anaerobic digestion start-up experiment on 19. 73% solid-content dewatered sludge from a reclaimed water plant in Beijing was discussed. The experiment in acidogenic phase used dewatered sludge as object,which inoculated with acid producing strain. The experiment in methanogenic phase was started with methane producing strain which solid content was 1. 38%,and then the acidified sludge with high solid content was added as substrate,until the solid content raised to 10% , this was to avoid the accumulation of VFAs. The results showed that the process of hydrolysis and acidification of dewatered sludge was fast. The concentrations of SC0D, VFAs and ammonia nitrogen reached about 80% of the maximum output in the 4th to 6th days , then the reaction spe ed became slow. The start-up solution with low-solid-content material in methanogenic phase was successful,the gas production was 20 ？23 m3 biogas/m 3 sludge when the solid content reached 10%,the highest daily gas production reached 3 467 mL/d,the highes t methane content reached 59. 46%.