Abstract:Currently, the dehydration efficiency of biological drying of food waste is relatively low and the treatment cycle is long, making it difficult to meet the demands of backend resource utilization. In this study, quicklime was employed to regulate three different treatments with initial pH values of 5, 6, and 7, referred to as CK, T1, and T2, respectively. The objective was to explore the dehydration efficiency of the biological drying reaction of food waste under various initial pH conditions, and to elucidate the transformation laws of water component behaviors during the reaction process. The results demonstrated that in the biological drying reaction, the effective accumulated temperatures for T1 and T2 were 512.0℃ and 509.1℃ respectively, which were higher than the 454.2℃ for the CK treatment. The dehydration rates for CK, T1, and T2 were 74.2%, 78.2%, and 76.0% respectively, indicating that the dehydration effect was best with the T1 treatment. Different initial pH regulations affected the degradation of organic matter, with the degradation rates for organic matter in the CK, T1, and T2 treatments being 26.9%, 30.0%, and 29.4%, respectively. However, there was no significant difference in the biological drying efficiency between treatments. During the biological drying process, free water was the main form of water occurrence. As the reaction proceeded, multilayer water (MW) and capillary water (CW) were continuously converted into entrapped water (EW), with CW and MW contributing significantly to water removal. Different initial pH values influenced the transformation and removal of water by affecting the water removal of MW and CW. This study can provide a reference for the regulation of initial pH in the industrial-scale application of biological drying of food waste.