Dynamic hydrolysis of organic fraction of municipal solid waste

Batch experiments of dynamic hydrolysis at different hydrolysate replacement frequencies in 96 h were conducted to evaluate the effects on anaerobic hydrolysis of organic fraction of municipal solid waste (OFMSW) caused by homogenization pretreatment, overturn, methanogenic effluent and hydrolysate replacement frequency (12 h, 24 h, 48 h, 96 h). Results show that the operation of overturn mixing improves the hydrolysis efficiency of OFMSW by 42.7% at most which happenes in the methanogenic-buffered scenario without homogenization, and the hydrolysis efficiency in the scenario without the operation of overturn mixing can only be 22.3%. Compared with the distilled water, the hydrolysis rate of un-homogenized OFMSW increases by 40.6% with methanogenic effluent as buffer. However, the increment is only 3.6% in the hydrolysis of homogenized OFMSW, which indicates that the homogenization has not significantly improved the hydrolysis efficiency, but increased the energy consumption. Hydrolysate replacement to some extent eliminates the inhibition of organic acid. The increments of weight loss by 11.4% and 40.7% are accomplished in the scenarios with hydrolysate replacement frequencies of 24 h·run-1 and 48 h·run-1, compared with that of 12 h·run-1. However, the energy consumption increases by 100% and 300%, respectively, suggesting that the hydrolysate replacement frequency of 12 h·run-1 is optimal.