Cleaning method for nanofiltration membrane and reverse osmosis membrane

A reverse osmosis membrane and nanofiltration technology, which is applied in the cleaning of reverse osmosis membranes and nanofiltration fields, can solve the problems of frequent replacement of nanofiltration membranes and reverse osmosis membrane elements, and achieve easy control of the cleaning operation process, ensure normal operation, and clean The effect of mild conditions

Inactive Publication Date: 2015-12-30
HENAN CLOUD WATER TREATMENT OPERATION SERVICES CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The invention provides a method for cleaning nanofiltration and reverse osmosis membranes, which can clean nanofiltration membranes and reverse osmosis membrane elements off-line, and solve the problem of replacing nanofiltration membranes and reverse osmosis membrane elements in existing landfill leachate treatment systems frequent questions

Method used

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  • Cleaning method for nanofiltration membrane and reverse osmosis membrane

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] This embodiment cleans the nanofiltration membrane, including the following steps:

[0045] (1) Test before cleaning: Fill the membrane element to be tested in the pressure vessel of the testing machine, the test solution is 2000ppm MgSO4 solution, the test pressure is 4.8kg / cm2, record the test results; measure the indicators of the membrane element before cleaning: The pressure difference is 1.3Mpa, the influent water conductance is 1580μs / cm, the product water conductance is 500μs / cm, and the water production rate is 0.3T / h. Then put the tested membrane elements into the cleaning machine for cleaning.

[0046] (2) Cleaning with acidic cleaning agent: take a hydrochloric acid cleaning agent with a mass fraction of 0.1%, dilute it with desalinated water to adjust the pH value to 2.2, and turn on the cleaning machine. When the value of the water pressure gauge on the cleaning equipment does not change, the color of the cleaning solution does not change. , When the chan...

Embodiment 2

[0050] This embodiment cleans the nanofiltration membrane, including the following steps:

[0051] (1) Test before cleaning: fill the membrane element to be tested in the pressure vessel of the testing machine, and the test solution is 500ppm CaCl 2 Solution, test pressure 7.0kg / cm2, record the test results; measure the indicators of the membrane element before cleaning: pressure difference 1.4Mpa, influent water conductance 1620μs / cm, product water conductance 496μs / cm, water production 0.4T / h. Then put the tested membrane elements into the cleaning machine for cleaning.

[0052] (2) acid cleaning agent cleaning: get the oxalic acid cleaning agent with a mass fraction of 0.5%, adjust the pH value to 2 by diluting with desalinated water, obtain an acid cleaning agent solution, add the cleaning active agent of 1% of the volume of the above cleaning solution, and then adjust the temperature to 35°C. Turn on the cleaning machine, when the value of the water inlet pressure gauge...

Embodiment 3

[0056] In this embodiment, the reverse osmosis membrane is cleaned, including the following steps:

[0057] (1) Test before cleaning: Fill the membrane element to be tested in the pressure vessel of the testing machine, adjust the conductivity of the test solution to 1500μs / cm with salt, and test the inlet pressure at 15.5kg / cm 2 , the water temperature was adjusted at 25°C, the test results; the indicators of the membrane elements before cleaning were measured: pressure difference 1.2Mpa, influent water conductance 1600μs / cm, product water conductance 520μs / cm, and water production 0.4T / h. Then fill the tested membrane elements in the cleaning machine for cleaning;

[0058] (2) Acid cleaning agent cleaning: get the hydrochloric acid cleaning agent with a mass fraction of 0.1%, adjust the pH value to 2.5 by diluting with desalinated water to obtain an acid cleaning agent solution, add 1% of the cleaning active agent by volume of the above cleaning solution, and then adjust the t...

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Abstract

The invention discloses a cleaning method for a nanofiltration membrane and a reverse osmosis membrane. The method comprises the following steps: testing before cleaning: loading a tester pressure vessel with a membrane element to be tested, and recording a test result; cleaning with an acidic cleaning agent: taking the acidic cleaning agent, adjusting the pH value of the acidic cleaning agent to be 10-12 through dilution with desalted water to obtain an acidic cleaning solution, and starting a cleaning machine for cleaning; cleaning with an alkaline cleaning agent: taking a surfactant, diluting with desalted water till the concentration is 0.02-0.03%, adjusting the pH value to be 10-12 by using a sodium hydroxide solution to obtain an alkaline cleaning solution, and starting the cleaning machine for cleaning; testing performance: taking the membrane element out of the cleaning machine, putting the membrane element into test equipment, and testing the recovery of the performance of the membrane element. According to the invention, the normal operation of the system can be guaranteed, the service life of the membrane element is prolonged to the maximum extent, the service lives of membrane elements of the nanofiltration membrane and the reverse osmosis membrane are prolonged to be 6-8 months, and the operating cost of a landfill leachate treatment system is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of membrane separation water treatment, in particular to a cleaning method for nanofiltration and reverse osmosis membranes. Background technique [0002] The treatment of landfill leachate is very difficult due to the complexity of its water quality and the high concentration of pollutants. The cost of treatment remains high. At present, the general process flow is pretreatment + biochemical treatment + advanced treatment (membrane method) process. [0003] The main problems of the landfill leachate treatment system: [0004] 1. Due to the poor water quality, the subsequent advanced treatment membrane elements are seriously fouled. The average service life of nanofiltration membranes and reverse osmosis membrane elements is 2 to 3 months. The water production of the system is greatly reduced due to pollution and fouling. Water quality has deteriorated severely. [0005] 2. Membrane elements are frequentl...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D65/06
Inventor 苗伟曼勤凯严备齐李全乐
Owner HENAN CLOUD WATER TREATMENT OPERATION SERVICES CO LTD
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