Deep dehydration method for sludge of sewage plant

Abstract

The invention discloses a deep dehydration method for sludge of a sewage plant. The method comprises the following steps: putting a primary sludge cake subjected to dehydration treatment by a belt filter press into a treatment tank; performing high-pressure impact on the primary mud cake in the treatment pond through a high-pressure water gun, the dosage ratio of the primary mud cake to water is 1: (4-5), then stirring continuously for 40 min or above, and preparing the mud; pumping the slurry into a mixing pipeline, mixing the slurry with a prepared flocculating agent, and feeding the mixture into a slurry storage tank; after mud and water are layered, extracting a supernate, and discharging the mud; and pumping the pug into a diaphragm filter press to obtain dewatered mud cakes with the water content being lower than 50%. According to the invention, the high-pressure water gun is innovatively utilized to impact, deblock and stir and soak the primary mud cake pretreated by the belt filter press for more than 40 minutes, so that the cost of conditioning agents is saved, the equipment cost is low, the sewage treatment efficiency and stability are improved, and the reduction and volume reduction of sludge are realized; and the dehydrated mud cake can be used for brick making, greening fertilizer, organic fertilizer processing in fertilizer factories, incineration in power plants and the like.

Description

technical field [0001] The invention belongs to the technical field of sludge treatment, and in particular relates to a deep dewatering method for sludge in a sewage plant. Background technique [0002] The treatment of sewage plant sludge has become a restrictive factor for the popularization and operation of sewage biological treatment technology. The first principle to solve the treatment and disposal of sludge in sewage plants is sludge reduction. Sludge reduction includes the reduction of sludge mass and volume, that is, reducing the amount of sludge produced and reducing the volume of sludge. The traditional sludge treatment is mainly to concentrate first, then break the wall and then flocculate. The concentration equipment consumes a lot of energy and occupies a large area, and a second flocculation is required before entering the dehydration equipment. There are common problems such as low treatment efficiency and high cost of chemicals. [0003] Chinese published p...

AI Technical Summary

Problems solved by technology

[0005] Although the above-mentioned technologies combine chemical treatment, mechanical crushing and ultrasonic modification to pretreat the sludge, the water content of the final sewage can only be reduced to below 60%, and there is still room for further dehydration. Ultrasonic reactors and mechanical crushing treatment equipment are used, and the equipment cost is relatively high. Third, chemical treatment is the main method in the above three pretreatment methods, and the addition of sludge conditioning agents in the chemical treatment process is very large, and there are still chemicals big cost problem