Extraction method for humic acid from MBR+NF concentrated liquor of low concentration divalent ion percolate

Abstract

The invention discloses an extraction method for humic acid, that is, a nanofiltration+two-stage ultrafiltration extraction method of humic acid in MBR+NF concentrated liquor of a sanitary landfill percolate of municipal solid wastes or a mixed percolate of a sanitary landfill and an incineration power plant. The method is advance, practical, economic, high in reduction degree, high in recovery rate of humic acid, good in operating stability and suitable for extracting humic acid in the MBR+NF concentrated liquor of the percolate with low concentration of bivalent salt ions, in particular loworganic matters and low salt content.

Description

technical field [0001] The invention belongs to the technical field of garbage treatment, and particularly relates to separating humic acid from the leachate of municipal solid waste sanitary landfill or the mixed leachate MBR+NF concentrate of garbage sanitary landfill and incineration power plant and concentrating it into humic acid-containing water-soluble fertilizer extraction method. Background technique [0002] Leachate is a kind of high-concentration organic wastewater with high pollution intensity and extremely difficult to treat. It is one of the main secondary pollutions of garbage sanitary landfills and waste incineration power plants. At present, the mainstream process of leachate treatment is MBR+NF. This combined process makes the treated effluent reach the discharge standard limit in the "Pollution Control Standards for Domestic Waste Landfill Sites" (GB16889-2008), and at the same time inevitably produces 1 / 6-1 / 4 MBR+NF membrane retentate (concentrated liq...

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Problems solved by technology

The latter also has disadvantages such as complex operation of the pretreatment process, environmental friendliness caused by adding more chemicals, and poor economic efficiency of the extraction process.

However, the authorized patent "Extraction Method of Humic Acid" (ZL201110272483.7) does not clearly indicate the scope of application. It is obviously not suitable for the extraction of humic acid in the membrane retentate with high content of divalent ions, and the single-stage ultrafiltration concentration is too large. Its operational stability, humic acid recovery and permeate concentration are adversely affected

[0004] In fact, some garbage sanitary landfills are located in areas with high rainfall; some landfills have too large rainwater collection areas or are not covered in time due to extensive operation and management methods of some landfills; Poor surface runoff or groundwater seepage mixed into leachate; these may lead to low concentration of organic matter and low salt content in leachate, resulting in low organic matter and salt content in the resulting MBR+NF membrane retentate, especially divalent salts lower content

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