Method for concentrating and dehydrating sludge

Abstract

The invention discloses a method for concentrating and dehydrating sludge. The method is characterized by comprising the following steps of: adding polyacrylamide into residual sludge of which the moisture content is 99 percent in an amount of 0.3 percent based on the mass of absolutely dry sludge for hardening and tempering the sludge; feeding the hardened and tempered sludge of which the moisture content is 99 percent into a flotation sludge concentrator through a pump for concentrating; feeding the concentrated sludge into a sludge hardening and tempering tank through a pump, adding caustic lime in an amount of 15 percent based on the mass of the absolutely dry sludge and polyaluminium chloride in an amount of 5 percent of based on mass of the absolutely dry sludge for further hardening and tempering; and performing filter pressing on the further hardened and tempered sludge by adopting a high-pressure diaphragm plate filter press. The method has the advantages of high system automatic degree, high concentration efficiency, low energy consumption, low mud moisture content and capability of making obtained sludge directly meet a filling requirement.

Description

technical field [0001] The invention relates to the field of sludge treatment, in particular to a sludge concentration and dehydration treatment method. technical background [0002] Sludge treatment is the process of sludge stabilization, reduction and harmlessness. Sludge treatment includes: concentration, dehydration, semi-drying, drying, anaerobic digestion and other treatment technologies. Among them, sludge concentration and dehydration are the first step in drying sludge. It has a great effect on reducing the volume of sludge for subsequent treatment (that is, volume reduction of sludge), facilitating sludge transportation and maintaining the normal operation of subsequent treatment processes. Significance. [0003] At present, the commonly used technologies for sludge pre-concentration include gravity concentration, flotation concentration, belt concentration, drum concentration, and centrifugal concentration. Among them, gravity concentration has problems such as l...

AI Technical Summary

Problems solved by technology

Among them, the belt filter press is one of the commonly used sludge dewatering equipment at present, but the water content of the belt filter press can only be controlled at about 75%, which is difficult to meet the current specification requirements, and the flushing water volume is large; The moisture content of the sludge output from the centrifugal dehydrator can only be controlled at about 75%, the SS of the output water is high, and the energy consumption is large; the drying operation of the drying bed is complicated and the environment is poor, and environmental and site problems limit its application.

With the current increase in the control requirements for sludge moisture content (≤60)%), the traditional sludge dewatering method is difficult to meet the current requirements

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