Sludge dewatering refers to the removal of water in the sludge by chemical or mechanical methods to reduce the volume of the sludge and facilitate subsequent treatment and disposal. When the moisture content of the sludge reaches more than 60%, in order to dehydrate the sludge to 60% more efficiently, some agents can be added to assist the sludge dewatering to 60%. Common sludge dewatering agents include the following:

1. iron salts: such as ferrous sulfate, ferric chloride, etc. This kind of agents can promote the sedimentation and condensation of sludge and improve its dewatering performance.

2. aluminum salts: such as polyaluminum chloride, aluminum sulfate, etc. These agents can be combined with organic matter in the sludge to form large colloidal particles and improve the cohesion and dewatering performance of the sludge.

3. minerals: such as dolomite, talc, etc. This kind of agent can fill the pores and voids in the sludge, enhance its mechanical properties and improve the dehydration effect.

4. organic polymers: sludge synergists. This kind of agent has good cohesion and sedimentation, can effectively consolidate the sludge, improve its dewatering performance, so that the sludge dewatering to 60%. It can greatly reduce the specific resistance of sludge dewatering process; It can completely or partially replace inorganic flocculants, without increasing the salt content of filtrate, and improve the operating conditions of sewage treatment plants.

After the sludge dewatering treatment, the sludge volume increment is small, and the mud cake amount is increased by 1.05 ~ 1.20 compared with the absolute dry sludge amount, which is 50% lower than that of the traditional lime method, and the subsequent treatment cost is low and the treatment efficiency is increased.

It should be noted that the selection of agents should be tested and screened according to the actual situation, and the optimal dosage and operating conditions should be determined according to the specific nature and characteristics of the sludge. At the same time, attention should be paid to safety during use to prevent harm to the human body and the environment.