高温预处理强化污泥与餐厨垃圾共消化

ENHANCEMENT OF CO-DIGESTION OF SLUDGE AND FOOD WASTE BY HIGH TEMPERATURE PRETREATMENT

污泥和餐厨垃圾共消化具有提高污泥稳定化的作用,为进一步强化污泥与餐厨垃圾共消化效果,提出高温预处理强化污泥与餐厨垃圾中温厌氧共消化的运行策略,并从宏观和微观2个层面探讨了共消化系统的运行机制。结果表明:污泥与餐厨垃圾经过1 d高温预处理后,其SCOD/TCOD从33.9%提高到65%;中温厌氧消化时的甲烷产率和有机物去除率高达0.54 L/g和78.8%(SRT=20 d)、0.76 L/g和56.6%(SRT=15 d),略高于某实际餐厨废弃物及市政污泥协同处理项目一期的0.53 L/g和53.5%,该项目采用150~170℃高温、1 MPa高压热水解进行预处理;采用Illumina MiSeq测序技术得出水解酸化菌属如Porphyromonadaceae、Draconibacteriaceae、Eubacterium和Romboutsia在高温预处理后的共消化系统中得到富集,促进了系统的水解和产酸过程,为系统中产甲烷菌Archaea提供了丰富的基质,强化了污泥与餐厨垃圾共消化产气效果。

Co-digestion of sludge and food waste can improve the stabilization of sludge.To enhance the co-digestion of sludge and food waste,the operation strategy of high temperature pretreatment and medium temperature anaerobic digestion was put forward.Moreover,the mechanism of the co-digestion system was discussed from the macro and micro levels,in order to provide technical support for the application of the strategy in practical engineering.Results showed that the operation strategy can not only improve the hydrolysis but also enhance the co-digestion effect.The ratio of SCOD/TCOD increased from 33.9%to 65%after one-day high temperature pretreatment of sludge and food waste.Methane production rate and organic removal rate of this study achieved 0.54 L/g and 78.8%(SRT=20 d),0.76 L/g and 56.6%(SRT=15 d),higher than the actual project of high temperature(150~170℃)and high pressure(1 MPa)for pretreatment.Illumina MiSeq sequencing revealed that hydrolytic/acidogenic bacteria,such as Porphyromonadaceae,Draconibacteriaceae,Eubacterium and Romboutsia,were enriched in the co-digestion system after high temperature pretreatment.The bacteria promoted hydrolysis/acidification,and made sure methanogens have enough substrate to produce methane.Therefore,the gas production from the co-digestion of sludge and food waste was strengthened.