Three chemical treatment methods for landfill leachate membrane filtration concentrate

Abstract

The invention relates to a three-chemical treatment method for landfill leachate membrane filtration concentrate, which is suitable for treating the membrane filtration concentrate produced in the "MBR+nanofiltration / reverse osmosis" treatment process of landfill leachate. After the membrane filtration concentrate is treated by the CSM colloidal separation membrane element, the colloidal membrane filtrate enters the high-pressure nanofiltration membrane element for reduction treatment, and the nanofiltration concentrate enters the high-pressure reverse osmosis element for further reduction treatment. After being mixed with the reverse osmosis clear liquid, it will be discharged up to the standard after advanced treatment by activated carbon filtration. The colloidal separation membrane concentrated liquid and reverse osmosis concentrated liquid will enter the drying device for stabilization treatment, and the dried salt mud mixture will be directly landfilled or incinerated. The invention organically combines colloid separation, high-pressure nanofiltration, high-pressure reverse osmosis, drying method and adsorption method, and can realize separation, reduction and stable disposal of landfill leachate membrane filtration concentrated liquid, and has low investment and operation costs. It solves the problem of treating landfill leachate membrane filtration concentrate.

Description

technical field [0001] The invention relates to a three-chemical treatment method for landfill leachate membrane filtration concentrate, belonging to the technical field of landfill leachate membrane filtration concentrate treatment. Background technique [0002] For landfill leachate treatment, the "Technical Specifications for Landfill Leachate Treatment Engineering" issued by the Ministry of Environmental Protection recommends the combined process of "pretreatment + biological treatment + advanced treatment". After biological treatment, landfill leachate needs to be further treated by nanofiltration membrane or reverse osmosis membrane to meet the discharge standard. The concentrated liquid produced by the membrane unit is relatively large, accounting for about 20% of the volume of landfill leachate, while the concentrated liquid of membrane filtration has the characteristics of high organic concentration, high salinity, and poor biodegradability. [0003] In the landfil...

AI Technical Summary

Problems solved by technology

The recharge method will cause the gradual accumulation of organic matter and salt in the landfill, but when the high-concentration and high-salt leachate returns to the membrane bioreactor (MBR) for degradation, it will cause the pressure of the membrane tube to rise, the system operation is extremely unstable, and the treatment effect will decline

[0005] Patent applications CN103570157A and CN104211245A use the evaporation method to treat the nanofiltration concentrate, but this method has high investment and high energy consumption, and the evaporation residue is hazardous waste, and the disposal cost is high

Patent applications CN101701025A and CN104478157A use the coagulation precipitation-advanced oxidation method to treat the nanofiltration concentrate. This method has a good effect on the removal of humic acids, but the residual organic nitrogen in the concentrate is oxidized to become nitrate nitrogen, and the effluent Total nitrogen is difficult to reach the standard

The patent application CN102701515A adopts the electrochemical oxidation method to treat the nanofiltration concentrated liquid. This method does not remove the hardness ions in the nanofiltration concentrated liquid. Long-term operation will cause fouling and blockage of the electrolytic plates, pipelines and reactors.

Patent applications CN1923875A, CN103964609A and CN 103626314A use the membrane concentration method to treat the nanofiltration concentrate, but the design of the membrane process is unreasonable, the degree of reduction is low, the output of the secondary concentrate is large, the recycled product is hazardous waste and it is difficult to use, and the comprehensive treatment cost very high

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