Membrane cleaning issues

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Membrane cleaning issues 1. For the cleaning of single pollutants, especially for membrane systems with organic contamination on the surface, it is necessary to use a combination of EDTA alkali cleaning and pickling. Cleaning with an alkaline formula alone will not be effective. In fact, colloids or microorganisms can be seen on the surface of more common organic pollutants, but the lower layer may be iron, aluminum and other oxides or silicate scale. In a certain cleaning, we only used EDTA alkali cleaning according to the recommendations of the membrane manufacturer. As a result, the operating pressure difference of the membrane increased but did not fall after the cleaning was put into operation. We immediately used citric acid pickling. After the membrane equipment was put into operation, everything was normal. 2. Use static soaking and dynamic circulation to alternately clean, saving time and effort, and achieving better results. 3. When membrane manufacturers recommend cleaning formulas, they often require the addition of anionic surfactants during alkali cleaning to facilitate the cleaning of organic matter. However, in actual use, the surfactants will produce a large amount of foam. After alkali cleaning, the cleaning time of pipes and solution tanks is long, which can easily cause cross-contamination. Try not to use it during cleaning. 4. When the second phase reverse osmosis equipment was first put into operation, when measuring SDI, there were fine quartz sand particles on the filter membrane. After disassembling the end plate of the reverse osmosis membrane, it was found that there were some sand particles at the inlet end of the membrane. The method of clamping with tweezers and sticking dough was used to remove the sand particles at the inlet end. Finally, the mechanical filter and activated carbon filter media were reinstalled. 5. The accumulation of membrane biological pollution will greatly increase the number of cleanings and significantly reduce the performance of the membrane. For power plants that use surface water as the water source, although regular regeneration and replacement of activated carbon can reduce membrane pollution to a certain extent, organic pollution still remains. * * Beyond the control range of our current traditional pretreatment equipment, it is urgent to use more advanced pretreatment technology such as ultrafiltration equipment, which can * * Ensure the economy and safety of the reverse osmosis system.