Experiment of Dehydration Capability of Municipal Sludge

Sludge is difficult to be dewatered without any pretreatment. The experiment of dewatering sludge by ultrasound, thermal hydrolysis and electrical pretreatment were studied. Ultrasound pretreatment proves it can adjust the structure of sludge, which will be restructure and change the water form increasing the water content which could be dispel easily. Thermal hydrolysis pretreatment disassembles agglomeration of Extracelluar Polymeric Substances (EPS), experimental results show that the bound water of sludge decrease with a longer treatment time and higher temperature, the water content is 84.74% at 170°C. The pretreatment of electrical dehydration gains good dewaterability as voltage increased in the AC electric field than ultrasound, thermal hydrolysis pretreatment.