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

Abstract

The invention discloses a method of reducing the town sewage and sludge and managing the resource belonging to solid waste treating technical field. The method is provided with following steps: diluting and breaking the dehydrated mud cake by sodium hydroxide solution, and stripping a large amount of organic matter in sludge, getting concentrated sludge and supernatant fluid by centrifugation; dehydrating the former after neutralization and regulation; obtaining a concentrated liquid and a filtered liquid after wind filtering and secondary ultrafiltration of the latter. The supernatant fluid contains lots of sodium hydroxide, and is reflowed to cycle. After disposal, the rate of water content of the dehydrate mud cake is reduced to about 70%, lowering 50% compared to the organic matter content before disposal, and lowering 2/3 of total mass. The concentrated liquid after ultrafiltration is mainly composed of organic matter with a large molecule such as humic acid, and with a low content of heavy metal. The pathogenic bacteria is deactivated which accords to the ''fertilizer utilization criteria'' of Ministry of Agriculture to produce a safe and efficient liquid organic fertilizer. The invention is suitable for the residual active sludge generated from the town sewage treating factory, for digesting the sludge and reducing the composite sludge and for managing the resource.

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 liquid separation performance cannot meet the requirements of this method

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