Treatment method of excess sludge

Abstract

The invention relates to the field of sludge treatment, in particular to a treatment method of excess sludge, which is used for treatment the excess sludge with low content of organic matters in a sewage treatment plant. The treatment method comprises the following steps of: performing ultrasonic pretreatment on the excess sludge; mixing the excess sludge after pretreatment with kitchen waste; and performing two-phase anaerobic process treatment on a mixture of the excess sludge and the kitchen waste. According to the treatment method of the excess sludge, disclosed by the invention, the ultrasonic pretreatment is firstly performed on the excess sludge with the low content of the organic matters for breaking microbial cell wall membranes and improving the mass concentration of dissolved COD (chemical oxygen demand) in the sludge; the excess sludge after the pretreatment is mixed with the kitchen waste according to a certain proportion, so that the characteristics of high content of the organic matters and abundant nutrition of the kitchen waste are fully utilized, the content of the organic matters and the carbon-nitrogen ratio in the sludge are improved, the biodegradability of the sludge is further improved, the operation is simple, the management is convenient, and the treatment method is suitable for the sludge treatment of large, medium and small-sized sewage treatment plants; and simultaneously, the treatment and the disposal of the kitchen waste can realize resource utilization.

Description

technical field [0001] The invention relates to the field of sludge treatment, in particular to an excess sludge treatment method for treating low-organic-matter excess sludge in a sewage treatment plant. Background technique [0002] Since the 1990s, our urban sewage treatment business has developed rapidly. With the improvement of sewage treatment rate, the generation of sewage sludge is also increasing. The problem of environmental pollution caused by sludge is becoming more and more prominent. How to treat and dispose of sludge scientifically and economically, as an environmental problem to be solved urgently, has attracted more and more attention. [0003] Taking Guangdong Province as an example, as of the end of September 2010, the daily output of sludge in the province reached 8,000 tons (with a moisture content of 80%), and 88% of the sludge was mechanically dehydrated to a moisture content of about 80%, and then transported to landfill , Stacking for final disposa...

AI Technical Summary

Problems solved by technology

[0004] However, with the substantial improvement of the living standards of urban residents, the average daily water consumption has gradually increased, coupled with problems such as the imperfect construction of urban sewage pipe networks, the COD mass concentration of sewage discharged from residential households has gradually decreased, causing sewage The influent COD concentration of the plant is low or even ultra-low, which is especially common in southern my country

It not only affects the normal operation of the sewage plant, but also makes the organic matter content of the residual sludge produced in the biochemical treatment process very low. It is very low (4-5:1), and the content of organic matter is low, so the mud quality of this kind of sludge is far from the optimal range of anaerobic digestion (C / N=10-20:1); and the main content of sludge The components are a large number of microorganisms, and the organic matrix required for anaerobic fermentation is contained in the cell membrane of the microorganism, while the rigid structure of the cell wall membrane hinders and shields the hydrolysis of easily degradable substances in the cell, which affects the biodegradability of the sludge

The above reasons hinder the application of sludge anaerobic fermentation in low organic matter residual sludge

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