Domestic waste leachate treatment system

Abstract

The present invention discloses a treatment system for household refuse leachate. The treatment system comprises a material tank, a first-stage nanofiltration unit, a second-stage nanofiltration unit and an evaporator, wherein a feed end of the first-stage nanofiltration unit is connected to an outlet of the material tank; a clear liquid outlet and a concentrated liquid outlet of the first-stage nanofiltration unit are respectively connected with a liquid inlet of the second-stage nanofiltration unit and a feed port of the evaporator; a permeate outlet and a concentrated liquid outlet of the second-stage nanofiltration unit are respectively led to an external drainage pipe network and the feed end of the first-stage nanofiltration unit; a concentrate outlet of the evaporator is led to an organic fertilizer or solidification treatment unit; and an evaporated liquor outlet of the evaporator is led to a liquid outlet of the second-stage nanofiltration unit. When the treatment system is used, the pretreated leachate is subjected to first-stage nanofiltration and evaporation concentration at first until the content of organic matters in the concentrate is as high as 50%, and then is used as an organic fertilizer or is subjected to solidification treatment, the clear solution after the first-stage nanofiltration is subjected to second-stage nanofiltration treatment, the concentrated liquid after second-stage nanofiltration is subjected to first-stage nanofiltration for cycle treatment, and the permeate after the second-stage nanofiltration is directly discharged.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a treatment system for leachate of domestic garbage. Background technique [0002] The so-called domestic waste leachate refers to the sewage seeped from the garbage in the urban domestic waste landfill. The large amount of domestic waste leachate is difficult to deal with, so it has been concerned by relevant departments in various countries as a social problem. At present, the domestic waste leachate is treated by the method of "biochemical + membrane concentration", but the analysis shows that the membrane concentration of the leachate can only reach 4-6 times when the above method is used, and the pass rate of the actual water production Not more than 85%. At the same time, the concentrated waste liquid after concentration cannot be processed again due to its large amount and high salt content. Usually, these concentrated liquids are returned to the garbage mountain...

AI Technical Summary

Problems solved by technology

At present, the domestic waste leachate is treated by the method of "biochemical + membrane concentration", but the analysis shows that the membrane concentration of the leachate can only reach 4-6 times when the above method is used, and the pass rate of the actual water production Not more than 85%. At the same time, the concentrated waste liquid after concentration cannot be processed again due to its large volume and high salt content. Usually, these concentrated liquids are returned to the garbage mountain or transported to landfills for storage.

That is to say, limited by the membrane concentration technology of the prior art, a large amount of concentrated waste liquid produced during the biochemical concentration of leachate cannot be treated reasonably. Therefore, how to realize the effective treatment of domestic waste leachate is still relevant. The technical bottleneck of the industry

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