Method of resource protection, decrement treatment of town sewage and sludge

Abstract

The invention discloses a method for reducing and recycling urban sewage sludge, which belongs to the technical field of solid waste treatment and disposal. It includes the following steps: the dewatered cake is diluted with sodium hydroxide solution and cracked to dissolve a large amount of organic matter in the sludge, and the concentrated sludge and supernatant are obtained through centrifugation. The former is dehydrated after neutralization and conditioning, and the latter is sand filtered. 1. After secondary ultrafiltration, concentrate and permeate are obtained. The latter contains a large amount of residual sodium hydroxide, which is refluxed for recycling. After treatment, the water content of the dehydrated cake is reduced to about 70%, which is 50% less than that of the pre-treatment organic matter content, and the total mass is reduced by 2 / 3; Low, pathogenic bacteria are inactivated, and can be made into a safe and efficient liquid organic fertilizer, which is in line with the "Guidelines for Fertilizer Use" of the Ministry of Agriculture. The invention is applicable to the reduction and resource treatment of excess activated sludge, digested sludge and mixed sludge produced by urban sewage treatment plants.

Description

technical field [0001] The invention belongs to the technical field of solid waste treatment and disposal, and in particular relates to a method for reducing and recycling urban sewage sludge. Background technique [0002] A large amount of sludge is produced in my country every year. According to the domestic sewage discharge of 30 billion tons in 2006, the treatment rate is 40%, and the sludge (water content 99%) is 1% of the sewage treatment volume, and the remaining sludge is about 120 million. tons, with the increase of my country's urban domestic sewage discharge and the improvement of treatment rate, the sludge production will continue to grow. A large amount of accumulated sludge not only occupies land, but also contains a large amount of organic nutrients and refractory organic matter, trace elements, pathogenic microorganisms, parasite eggs, heavy metals and other components, which may pollute the ecological environment through different channels. To properly deal ...

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Problems solved by technology

In other studies, alkali cracking sludge is mainly used for pretreatment of sludge digestion. Since its purpose is to assist sludge hydrolysis and avoid adverse effects on subsequent digestion, the alkali concentration used is low (0.08-0.16g / gDS ), under this concentration condition, the sludge reduction effect and solid-liquid separation performance cannot meet the requirements of this method

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