Sludge dewatering method for waste paper deinking technology

Abstract

The invention relates to a new sludge dewatering method used in waste paper de-inking technology. It includes the following steps: diluting sludge, storing in sludge storage pool, entering gravitational bed, auger delivery, screw press, sludge discharging; adding cationic polyacrylamide in entering gravitational bed; separating and water discharging in gravitational bed and screw press. Its feature is adding 600-800mg / L concentrated sulfuric acid in sludge storage pool which can increase gravitational bed processing effect, reduce 95% suspended matter in filtrate, cut down dissolubility CODcr1100mg / L, thereby omit air floatation and chemicals to make the filtrate discharge directly, make sludge self draining concentration reach 18-20% that one times higher than original method after processing by gravitational bed, reduce pollutant handing cost, has considerable annual economic benefit.

Description

technical field [0001] The invention relates to a sewage treatment method, in particular to a new sludge dehydration method in the waste paper deinking process. Background technique [0002] In order to reduce the pollution of the paper industry to the water environment, the domestic pulp and paper industry has adjusted its raw material structure and gradually shifted from straw pulp papermaking to recycled paper pulp and papermaking. Straw pulp papermaking requires 50-100m of drainage per ton of paper 3 , and the use of waste paper to make paper can save water, and the water consumption per ton of paper is only 10m 3 Left and right, the production of newsprint from recycled paper pulping and papermaking is a mature technology at home and abroad. For every ton of waste paper pulp produced, about 0.18 tons of deinking sludge will be generated. These sludges need to be separated from sludge and water in the production workshop by using gravity bed, micro air flotation and oth...

AI Technical Summary

Problems solved by technology

[0008] 1. The filtration performance of the sludge on the gravity bed is poor, the sludge concentration of the gravity bed is low, and the pollutants contained in the filtrate must be further treated by micro-air flotation before discharge, and the micro-air flotation needs to add PAM twice

[0009] 2. PAM only separates the fibers from the solution, but does not separate the colloids in the dispersion. Most of the colloids are finally discharged, which increases the pollution load of the sewage treatment plant, which is manifested by high COD in the drainage

[0010] 3. The concentration of the sludge entering the screw press is only 10%, so most of the suspended solids are lost with the filtrate during the extrusion process, causing the suspended solids in the drainage to be too high

And affect the final sludge concentration, less than 50%, affecting the stable operation of sludge incineration

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