Sewage sludge treatment method

Abstract

The invention discloses a sewage sludge treatment method. The sewage sludge treatment method comprises a first step of utilizing a freeze drying energy circulating system to continuously freeze sludge in a sludge freezing container, unfreezing the sludge after continuous freezing, and performing freezing and unfreezing repeatedly; a second step of dehydrating the sludge having undergone freezing and unfreezing treatment in a filter pressing device, wherein dehydration comprises a filter pressing stage and a squeezing dewatering stage, and enabling the sludge to undergo filter pressing to be chunk mud-cake-shaped sludge low in moisture content; a third step of crushing the chunk mud-cake-shaped sludge in a crushing device and forming small sludge particles; a fourth step of conveying the crushed sludge particles to enter a sludge drying device to be dried, enabling the freeze drying energy circulating system to release heat through a condenser, transferring heat to air, and enabling the hot air to enter the sludge drying device to dry the sludge particles. According to the sewage sludge treatment method, chemical agents do not need to be added to sludge, the sludge treatment amount is not increased in the treatment process, and recycling of working medium energy greatly improves sludge freezing efficiency and heat utilization rate.

Description

technical field [0001] The invention relates to the field of sludge treatment, in particular to a sewage sludge treatment method. Background technique [0002] A large amount of sludge is produced in the process of sewage treatment, which accounts for about 0.3%-0.5% of the treated water volume. The investment and operation cost of sludge treatment are very huge, and the cost of sewage sludge treatment generally accounts for 10% of the operating cost of sewage treatment plants. 20%-50%, bringing a heavy burden to sewage treatment. Sludge dehydration is a very important link in sludge treatment and disposal, and is of great significance to subsequent drying, incineration, resource utilization, and landfill of sludge. The key to sludge dewatering is to improve the dewatering performance of sludge. The current traditional treatment method is to condition it first by adding flocculant, and then perform mechanical dehydration by filter press to form sludge with a moisture conten...

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Problems solved by technology

[0005] In view of this, the present invention aims at the problems in the above-mentioned prior art that increasing the flocculant will increase the treatment capacity of sewage sludge, low freezing efficiency and high cost, and provides a treatment process that does not increase the treatment capacity of sewage sludge, freezing Sewage sludge treatment method with high efficiency and high energy utilization

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