A research on the strengthening effect of sludge charcoal on activated sludge process in sewage treatment

With the rapid development of urbanization, the number of urban sewage treatment plants is increasing, wastewater treatment volume is gradually becoming large, and correspondingly, the sludge production capacity has a rapid growth. As a new method of sludge disposal, sludge carbonization is characterized by low energy consumption, simple products, and wide resource utilization prospects, which is of great help to solve problems of current sludge disposal in China. The residual sludge from sewage plant was used as raw material in this study in order to investigate the physical and chemical properties of sludge charcoal after high temperature carbonization and explore the enhancement in the removal of pollutants including COD_cr, NH₃-N, TN, and TP during sewage treatment with the used sludge charcoal. The results show that the optimal dosing amount of sludge charcoal was 2 g.L^-1 when it was added into SBR equipment at one time, while the optimal dosing amount is 0.06 g.L^-1 when it was added into SBR equipment with each influent process. The enhanced removal effect of pollutants in sewage treatment process mainly depended on the physical adsorption and intensified bio-degradation of sludge charcoal, and activated sludge and sludge charcoal were synergistic in water treatment. The removal effect of pollutants is strengthened in the physical adsorption-bio-degradation-sludge charcoal reproduction-re-adsorption system. These suggested that sludge charcoal could be promising for the enhancement of pollutant removal in sewage through activated sludge process.