含固率对污水厂剩余污泥和生活垃圾混合厌氧发酵的影响

Influence of Total Solid Ratio on Anaerobic Co- digestion of Municipal Solid Waste and Excess Sewage Sludge

以城市污水处理厂剩余污泥和生活垃圾的混合物为厌氧发酵底物,在中温(35℃)条件下,采用序批式厌氧发酵法进行试验。研究了不同含固率下的日产气量、累计产气量、TS和VS去除率、发酵液p H值等变化规律。研究结果表明,在适宜范围内提高进料含固率可提高系统累积产气量,但会推迟产气高峰,延长发酵周期。其中,物料含固率为3%的试验组产气效果最佳,日产气量高达537 m L,累计产气量为7 905 m L,过高或过低的含固率均不利于产气以及TS和VS的去除。混合物料含固率越高,发酵液p H值降低越多。控制合理的进料含固率能够增强系统缓冲能力,有效缓解城市生活垃圾易水解导致的p H值急剧下降情况。

A study on mesophilic anaerobic co- digestion（ 35 ℃） of municipal solid waste（ MSW） and excess sewage sludge（ ESS） is conducted in four serum bottles to compare the production of biogas,removal rate of VS and TS,p H value of the digestive effluent by sequencing batch system. The results show that with the increase of total solid ratio within a certain extent,the production of biogas can be increased,but may delay the biogas yield peak and prolong the fermentation period. The highest accumulated biogas yield of all groups is 7 905 m L at total solid ratio of 3% with daily biogas production of 537 m L. Extra higher or lower of total solid ratio is not conducive to gas production and removal of TS and VS. The higher the total solid ratio of mixed material,the more p H value of the digestive effluent decreased. If the total solid ratio can be controlled to appropriate range,buffer capacity of the system can be strengthened and it is effective to alleviate the decrease of p H resulted from the hydrolysis of municipal solid waste.