Sludge dewatering method for urban sewage plant

Abstract

The invention discloses a sludge dewatering method used for an urban sewage plant. The method comprises the following steps of: putting original sludge of the urban sewage plant in a container, wherein the moisture content of the sludge is more than 90 percent, and stirring fully and uniformly; adding mixed coagulant aids of dolomite and quick lime into the obtained sludge and uniformly stirring; adding inorganic flocculant, stirring uniformly, adding a polyacrylamide (PAM) flocculating agent, and stirring uniformly; and feeding the obtained sludge into a plate-and-frame filter press, squeezing and dewatering the sludge, keeping pressure for 5 to 30 minutes, and decompressing and discharging. The sludge of the urban sewage plant is conditioned and flocculated further, and then is filtered, squeezed and dewatered, so that moisture in the original sludge in the sewage plant, which is not dewatered by a belt filter press, can be dewatered effectively, the treatment process of the sludge dewatering method is simple, and the sludge dewatering method is low in treatment cost.

Description

technical field [0001] The invention belongs to the technical field of sludge treatment, and in particular relates to a sludge treatment method of an urban sewage plant, in particular to a dehydrating agent for sludge dehydration composed of a coagulant aid and a flocculant and a sludge dehydration method. Background technique [0002] With the acceleration of my country's urbanization process, the rate of urban sewage treatment has increased year by year. The activated sludge process is one of the main methods for urban sewage treatment. In the process of sewage treatment, a large amount of residual sludge is inevitably produced. These sludges contain The water volume is high, the particles are small, and most of them are hydrophilic negatively charged biological particles, and the sludge contains a large amount of organic matter, heavy metals, pathogenic bacteria, etc. If the sludge that has not been properly treated and disposed of enters the environment, it will directly b...

AI Technical Summary

Problems solved by technology

At present, most of the activated sludge in urban sewage plants use a belt filter press to dehydrate the sludge. The dehydrated sludge has a high moisture content, generally reaching about 80%. Due to the high moisture content, it cannot be directly disposed of in a sanitary landfill. It is not conducive to the final disposal and resource utilization of sludge, which makes the cost of sludge disposal high

In the current urban sludge treatment method, the water content of the sludge can reach about 50%. Although the solid content of the sludge is high, the treated sludge is dehydrated by a belt filter press. About 80% of the sludge, and the whole treatment process is complicated and the treatment cost is high