Influence of Initial Physico-Chemical Properties on Biophysical Drying of Dewatered Urban Sewage Sludge

摘要

This paper summarized a biophysical drying approach for dewatered urban sewage sludge with high efficiency and low energy consumption. Biophysical drying using the energy of dewatered sewage as biomass resource improved the enthalpy of sludge matrix. Convective evaporation, which is governed by the thermodynamic equilibrium between wet waste matrix and the air flowing through the matrix, speeded up moisture content removal from the waste. This paper focused on the influence of biomass physico-chemical properties on biophysical drying of dewatered urban sewage sludge and studied the efficiency of moisture removal. Under the optimization condition, the moisture content reduced from 70.5% to 43.1% in 9 d, and the average rate of moisture content removal was 265.37 kg (H2O)/d·t (dry sludge). Moreover, during the process of biophysical drying, sludge flocs were disintegrated, resulting in fast convective evaporation and interstitial water transference.