Chemical cleaning method for nanofiltration or reverse osmosis membranes

A reverse osmosis membrane and chemical cleaning technology, which is applied in the field of nanofiltration and reverse osmosis membrane chemical cleaning, can solve the problems of high cleaning cost, acid resistance, weak alkalinity, neglect of cleaning sequence and cleaning parameter control, etc., and achieve water production Improvement of yield and operating pressure, improvement of clear liquid treatment capacity, and improvement of clear liquid treatment capacity

Inactive Publication Date: 2019-01-18
HUNAN JUNXIN ENVIRONMENTAL PROTECTION CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this cleaning method is that the composition of the alkaline cleaning agent used is too complex, resulting in high cleaning costs, and the alkaline cleaning agent contains organic silicon, which cannot be used to clean nanofiltration/reverse osmosis membranes, because silicon Substances entering the membrane element will cause damage to the membrane, thereby affecting the service life and filtration effect of the membrane; at the same time, this cleaning method does not consider the influence of cleaning temperature, pH, and soaking time on the reverse osmosis membrane material during the cleaning process, and these factors It is very easy to cause irreversible damage to the nanofiltration/reverse osmosis membrane, which will seriously reduce the service life and filtration effect of the nanofiltration/reverse osmosis membrane
However, the existing chemical cleaning agents are general applicable cleaning agents, which are not highly targeted an

Method used

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  • Chemical cleaning method for nanofiltration or reverse osmosis membranes

Examples

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Embodiment 1

[0036] In this example, the old landfill leachate waste water is adjusted to the C / N ratio with fresh leachate, then enters the MBR biochemical treatment, and then enters the ultrafiltration system to realize the separation of mud and water, and the ultrafiltration water is stored in a water storage tank. Nanofiltration / reverse osmosis membrane is used for advanced treatment of ultrafiltration product water, which meets the emission standards in Table 2 of GB16889-2008.

[0037] In this example, when the conductivity of the ultrafiltration water is 14000-15000us / cm, the total hardness is 4000-6000mg / L, the COD is 400-500mg / L, and the water temperature is 32-36°C, nanofiltration / reaction Osmotic membrane treatment of ultrafiltration product water. Nanofiltration / reverse osmosis membrane is made of polyamide, Dow membrane, reverse osmosis model SW30HRLE-370 / 34i, nanofiltration membrane model NF270-400. The operating pressure of the nanofiltration membrane module is 5-6.5bar, an...

Embodiment 2

[0052] In this example, the old landfill leachate waste water is adjusted to the C / N ratio with fresh leachate, then enters the MBR biochemical treatment, and then enters the ultrafiltration system to realize the separation of mud and water, and the ultrafiltration water is stored in a water storage tank. Nanofiltration / reverse osmosis membrane is used for advanced treatment of ultrafiltration product water, which meets the emission standards in Table 2 of GB16889-2008.

[0053] In this example, when the conductivity of the ultrafiltration water is 14000-15000us / cm, the total hardness is 4000-6000mg / L, the COD is 400-500mg / L, and the water temperature is 32-36°C, nanofiltration / reaction Osmotic membrane treatment of ultrafiltration product water. Nanofiltration / reverse osmosis membrane is made of polyamide, Dow membrane, reverse osmosis model SW30HRLE-370 / 34i, nanofiltration membrane model NF270-400. The operating pressure of the nanofiltration membrane module is 5-6.5bar, an...

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Abstract

The invention discloses a chemical cleaning method for nanofiltration or reverse osmosis membranes. The chemical cleaning method includes the following steps: (1) pickling the nanofiltration or reverse osmosis membranes by acidic solutions; (2) cleaning the nanofiltration or reverse osmosis membranes by product water after pickling; (3) performing alkali washing on the nanofiltration or reverse osmosis membranes by alkaline cleaning solutions; (4) cleaning the nanofiltration or reverse osmosis membranes by the product water after alkali washing to complete cleaning of the nanofiltration or reverse osmosis membranes. The chemical cleaning method has the advantages that various pollutants on the nanofiltration or reverse osmosis membranes can be efficiently removed, the operating pressure ofthe nanofiltration or reverse osmosis membranes can be reduced, the yield of clear liquid of the nanofiltration or reverse osmosis membranes can be increased, the service life of the nanofiltration or reverse osmosis membranes can be prolonged, the power consumption of the clear liquid can be lowered, and stable operation of landfill leachate treatment plants can be guaranteed; the chemical cleaning method has the advantages of simple process, convenience in operation, low cleaning cost, high cleaning efficiency, good cleaning effect, high application value, good application prospect and thelike.

Description

technical field [0001] The invention belongs to the technical field of landfill leachate treatment, and relates to a chemical cleaning method for nanofiltration and reverse osmosis membranes. Background technique [0002] In fresh landfill leachate, the B / C is high and the total hardness is high, so it needs to be treated by MBR, ultrafiltration, nanofiltration and reverse osmosis successively, among which nanofiltration / reverse osmosis membrane (NF / RO membrane) to treat the ultrafiltration effluent. However, with the continuous operation of the NF / RO membrane, more and more pollutants are accumulated on the surface of the NF / RO membrane. The effluent water quality deteriorates. Therefore, during the operation of the nanofiltration / reverse osmosis membrane, it must be cleaned regularly to maintain the designed operating pressure and water yield. [0003] The existing NF / RO membrane cleaning methods are divided into two categories: physical cleaning and chemical cleaning....

Claims

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Application Information

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IPC IPC(8): B01D65/02
CPCB01D65/02B01D2321/162B01D2321/164
Inventor 高新周俊蔡斌肖宇轩田黎黎
Owner HUNAN JUNXIN ENVIRONMENTAL PROTECTION CO LTD
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