Pretreatment method of improving dewatering performance of urban sludge

Abstract

The invention relates to a pretreatment method of improving the dewatering performance of urban sludge. The pretreatment method comprises the following steps of: respectively adding a coagulant and afilm breaking agent to remaining activated sludge through a front feeding port and rear feeding port of a pipeline mixer, and carrying out mixed reaction; introducing the sludge with the added coagulant and film breaking agent into a high mixing tank, and adding a neutralizing agent while stirring to obtain the sludge with the pH value of 6.2-7.0; continuously pouring the obtained sludge into an inclined plate water knockout drum, carrying out gravity sedimentation on the sludge, and dividing the sludge into an upper clear liquid layer and a lower sludge layer after sedimentation, wherein theupper clear liquid layer overflows from an overflow port of the inclined plate water knockout drum, the lower sludge continuously settles and accumulates, and the moisture content of the bottom sludgeis reduced to 94-98 wt.%. The sludge pretreatment method integrates sludge modification and concentration, and overturns the traditional pre-concentration and after-modification sludge pretreatment process, is short in process and realizes the continuous large-scale treatment of the sludge; and conditions are easy to control. Agents used in the treatment process do not have any solid compatibilization, do not affect the calorific value of the sludge and are beneficial to the subsequent disposal of the sludge.

Description

Technical field [0001] The present invention belongs to the technical field of sludge treatment, and specifically relates to a pretreatment method for improving the dewatering performance of urban sludge. The present invention is particularly suitable for residual activated sludge with high moisture content produced by domestic sewage treatment plants and industries with high organic matter content. sludge. Background technique [0002] In our country, affected by the idea of ​​"heavy water over sludge", sludge treatment owes too much debt to sewage treatment, which is a "big problem". Therefore, from the general idea of ​​the development of sludge treatment and disposal technology, harmlessness and stabilization are the basic requirements of various treatment technologies, and reduction is an urgent matter. It can slow down the pressure of rapid sludge growth. The key to reduction is Dewatering, whoever masters efficient sludge dewatering technology can dominate the market; ene...

AI Technical Summary

Problems solved by technology

[0003] The traditional sludge conditioning and breaking technology generally uses ferric chloride, lime, PAM and other agents, which are costly and have a large amount of addition, which will increase the solids of the sludge, which is not conducive to subsequent disposal, and the on-site operating environment is poor. It cannot run continuously, and it is easy to cause secondary pollution and other problems

[0004] The traditional sludge pretreatment process is concentrated first and then modified by adding drugs. Generally, mechanical concentration or gravity concentration is used for concentration. Addition increases the cost of chemicals, and it cannot run continuously. In addition, it also increases the volume of sludge and the amount of follow-up treatment, which is contrary to the reduction of sludge.

[0005] The traditional sludge dehydration pretreatment process flow: excess sludge pumping room→sludge storage tank→sludge thickening tank→sludge modification tank→transfer tank→filter press, the sludge is lifted many times, the process is long, and the operation Complex, high operating and investment costs

[0006] In the deep dehydration process, there are shortcomings such as low equipment utilization rate and small deep dehydration range. For example, some processes are limited to dehydration of sludge with a moisture content of 80%, and some processes are limited to deep dehydration of sludge with a moisture content of 99%. only down to 60%

Moreover, these processes are difficult to achieve continuous production and automation.

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