接种比对餐厨垃圾干式厌氧发酵启动的影响

Effect of different inoculation ratios on start-up performances of dry anaerobic digestions for kitchen waste

针对不同接种比对餐厨垃圾干式厌氧发酵启动的影响,对比分析了VS接种比分别为0.36和0.90两种情况下,餐厨垃圾干式厌氧发酵启动过程中pH、NH4-N、COD、VFA、甲烷含量等指标的变化。实验结果表明,启动初期2组样品pH分别快速降至4.74和5.68,均呈酸化状态,经碱液调整后,接种比为0.36的处理仍无法正常产气,接种比为0.90的处理,pH逐步提高,系统正常运行,经72 d的发酵实验,COD去除率达90.29%,甲烷含量高于60%的沼气产量达255.4 L,分析可见,VS接种比是干式厌氧发酵处理的重要参数;此外,与传统湿式厌氧发酵处理相比,餐厨垃圾干式厌氧发酵在较高的VFA和氨氮浓度下,仍能正常运行,采用干式厌氧发酵技术处理餐厨垃圾是可行的。

To analyze the start-up performances of different inoculation ratio on dry anaerobic digestions for kitchen waste,two parallel treatments with different inoculation ratios（ according to the volatile solid amount of substrates and inocula） 0. 36 and 0. 90 were investigated,and the change of parameters including pH,NH4-N,COD,VFA,content of methane were studied. The results indicated that pH of the two treatments quickly dropped to 4. 74 and 5. 68,respectively at initial phase,which resulted in acidified conditions,by adjusting of alkali,the treatment that under inculcation ratio of 0. 36,still couldn＇t produce methane,The treatment that under inculcation ratio 0. 90,could run stably after self-repairing. Over 72 days operating period,the removal rate of COD reached to 90. 29%,biogas with methane content of higher than 60%,yielded up to 255. 4 L. Therefore,the inoculation ratio is a significant parameter for dry anaerobic digestion of kitchen waste. Moreover,comparing with traditional wet anaerobic digestion,dry anaerobic digestion can run at higher concentrations of VFA and NH4-N,it is a feasible processing technology for kitchen waste recycling.