Method for conditioning and dehydrating residual sludge

Abstract

The invention relates to the technical field of residual sludge treatment, in particular to a process method for conditioning and dehydrating residual sludge. The method particularly comprises the following steps: (1) adding acid into the residual sludge to be treated and with the water content of 90 to 95 percent and adjusting until the pH value is between 4.0 and 6.0; (2) adding quaternary ammonium salt cationic organic matters into the conditioned sludge in the step (1) and performing hybrid reaction; (3) adding a dehydration aid into the conditioned sludge in the step (2) and stirring uniformly; and (4) adding coagulant into the conditioned sludge in the step (3) and mechanically dehydrating after mixing and stirring. The extracellular polymers on sludge flocs are stripped and partially hydrolyzed by a chemical conditioning mode, microbial cells are dissolved, a large amount of bound water is released, and the water permeability of the sludge is improved by utilizing the aid, so that the dehydration performance of the sludge is integrally improved, the water content of the sludge is reduced, the dehydration time is shortened and the dehydration cost is reduced.

Description

technical field [0001] The invention relates to the technical field of excess sludge treatment, in particular to a process method for conditioning and dehydrating excess sludge. technical background [0002] With the development of our country's society and urbanization, the amount of urban sewage is increasing, the number of corresponding sewage treatment facilities is also increasing, and the by-product of sewage treatment - sludge is also increasing. How to properly handle and dispose of these increasingly large amounts of sludge has become an urgent problem to be solved in my country's environmental protection. [0003] At present, the sludge dewatering process and dehydration equipment of most domestic sewage treatment plants can only reduce the moisture content of sludge from more than 98% to 80%, which cannot meet the requirements of most sludge disposal processes for low sludge moisture content. [0004] After the sludge is treated by biological method, the water in...

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Problems solved by technology

[0007] The patent application number 200810198538.2 uses the surfactant dodecyldimethylbenzyl ammonium chloride to treat the sludge, which can reduce the specific resistance of the sludge, but the inventor found that the single use of dodecyldimethylbenzyl Although ammonium chloride can peel off part of the EPS and reduce the bound water content, the sludge floc particles become smaller, which is easy to block the filter holes of the filter cloth, making it difficult to filter and stick to the filter cloth.

The patent with the application number 200810198539.7 discloses an additive and dehydration method for sludge dewatering, including cationic surfactant with a weight ratio of 1.42%-2.07% of sludge solid content, 4.92%-10.18% polyaluminum chloride And polyacrylamide, 5%-10% of the medium after picking edible mushrooms, but the use of polyacrylamide can lead to the re-agglomeration of EPS dispersed in water, without using the reduction of the water content of sludge, while the edible mushroom picking medium There are many types, and the materials and properties used are quite different, which greatly affects its practical applicability.

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