Biodrying of municipal solid waste with high water content by combined hydrolytic-aerobic technology.

The high water content of municipal solid waste (MSW) will reduce the efficiency of mechanical sorting, consequently unfavorable for beneficial utilization. In this study, a combined hydrolytic-aerobic biodrying technology was introduced to remove water from MSW. The total water removals were proved to depend on the ventilation frequency and the temporal span in the hydrolytic stage. The ventilation frequency of 6 times/d was preferable in the hydrolytic stage. The hydrolytic span should not be prolonged more than 4 d. At this optimal scenario, the final water content was 50.5% reduced from the initial water content of 72.0%, presenting a high water removal efficiency up to 78.5%. A positive correlation was observed between the organics losses and the water losses in both hydrolytic and aerobic stages (R = 0.944, p < 0.01). The evolutions of extracellular enzyme activities were shown to be consistent with the organics losses.