Method for producing liquid organic fertilizer by using organic fertilizer

Abstract

The invention discloses method of producing liquid organic fertilizer by organic belonging to solid wastes disposal field, including: co-treating the residual sludge with 98 percent moisture content by ultrasound and sodium hydroxide to make the organic matters dissolve out; getting concentrated sludge and supernatant fluid after centrifugation; dehydrating the concentrated sludge after neutralization in a routine method; sand leaching and ultrafiltration treating the supernatant fluid twice after centrifugation to get a concentrated liquid containing macromolecule organic matter such as humic acid and the filtrate containing low molecular organic matter; the filtrate entering into the sewage treating plant for a primary treatment. Disposed dehydrated sludge cake has 70-80 percent moisture content and a reduction of the content of organic matter of 30-50%. The concentrated liquid by ultrafiltration is mainly composed of macromolecule organic matter and with a low content of heavy metal, and can be an organic liquid fertilizer, and complies the rule of using green food fertilizer. The invention is suitable for the sludge with a high organic matter content such as residual sludge and digested sludge.

Description

technical field [0001] The invention belongs to the technical field of solid waste treatment and disposal, and in particular relates to a recycling method for preparing liquid organic fertilizer from excess sludge. Background technique [0002] Most of the urban domestic sewage in my country is treated by the activated sludge method, and a large amount of excess sludge is produced every year. According to the discharge of domestic sewage in 2006, 30 billion tons, the treatment rate is 40%, and the sludge (water content 99%) is produced as sewage According to 1% of the treatment capacity, about 120 million tons of residual sludge will be produced. With the increase of domestic sewage discharge and the improvement of treatment rate in my country, the amount of excess sludge will continue to grow. A large amount of organic matter contained in sludge will pollute the ecological environment if it is not handled properly. If it is extracted and used as fertilizer, it can not only ...

AI Technical Summary

Problems solved by technology

Ultrasonic treatment mainly utilizes the mechanical impact force generated by cavitation effect, while sodium hydroxide treatment mainly utilizes OH - Hydrolysis or destruction of microbial extracellular polymers and some organic matter in the cell membrane, but the degree of hydrolysis of proteins, polysaccharides, and DNA is limited, and sodium hydroxide and humic acid produce humic acid sodium salt, so ultrasound and hydroxide Sodium joint treatment can also reduce the degradation of macromolecular organic matter, which is beneficial to the separation of these macromolecular organic matter by ultrafiltration, while heat treatment, chemical oxidation and biological treatment will degrade macromolecular organic matter into small molecular organic matter, which is not conducive to extraction and production of organic fertilizers

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