Patent ID: 11643350

Abstract:
The disclosure relates to a treatment method for sludge utilization in a sewage treatment plant, in particular to a method for reducing heavy metal content of sludge-based biocoke. The disclosure includes following steps (1) to (5): step (1): concentrating a residual sludge produced by a municipal sewage treatment plant to be with a moisture content of 95-98%; step (2): conditioning the concentrated sludge in a sludge bioleaching tank for 48 hours, with a pH value of the sludge being reduced to below 4.5; step (3): pumping the conditioned sludge into a high-pressure diaphragm plate and frame for a press filter dewatering to obtain a dewatered cake with a moisture content less than or equal to 50%; step (4): delivering the dewatered cake into a sludge dryer for crushing, heating and drying to obtain the dried sludge with a moisture content of 15-22%; and step (5): carbonizing the dried sludge into sludge-based biocoke at a high temperature in a pyrolytic carbonization device with a carbonization temperature of 500-650° C.