Chemical cleaning method of reverse osmosis membrane

Abstract

The invention relates to a chemical cleaning method of a reverse osmosis membrane. In the method, aiming at a reverse osmosis membrane for processing PTA refining wastewater, inorganic pollutants which are formed by cobalt ions, manganese ions, hydroxide thereof and the like and are deposited and adsorbed on the surface of the membrane are dissolved and eluted by using acid rinse prepared by citric acid and sodium bisulfite; organic colloid pollutants deposited and adsorbed on the surface of the membrane are dissolved and eluted by using alkaline rinse containing sodium dodecyl benzene sulfonate and sodium hydroxide. The method can elute the pollutants on the surface effectively, restore operating flux, operating pressure and desalination rate of the reverse osmosis membrane, and ensure that the process of processing the reverse osmosis membrane for the PTA refining wastewater is stable in operation.

Description

technical field [0001] The invention relates to a chemical cleaning method of a reverse osmosis membrane, in particular to a chemical cleaning method of a reverse osmosis membrane for treating PTA refining wastewater. By adopting the method of the invention, the pollution of the reverse osmosis membrane can be effectively removed, and the stable progress of the PTA wastewater membrane treatment process can be ensured. Background technique [0002] In order to treat purified terephthalic acid (PTA) wastewater and achieve the purpose of wastewater reuse, a treatment method based on membrane separation is generally used. The method is characterized by: removing macromolecules and colloidal substances in wastewater by ultrafiltration, Reverse osmosis removes organic matter and metal ions in wastewater, and then further removes organic matter and metal ions in wastewater by ion exchange. The treated wastewater meets the water quality requirements for PTA production process water ...

AI Technical Summary

Problems solved by technology

[0005] The composition of PTA refining wastewater is complex, which contains colloidal substances formed by organic substances such as cobalt, manganese ions and PTA. Before membrane treatment, most of the colloidal substances in the wastewater can be precipitated into suspended solids by adjusting the pH and water temperature. , and then removed by filtration and ultrafiltration, but there is still a small amount of unprecipitated colloidal substances entering the reverse osmosis unit. With the increase of the reverse osmosis operation time, the reverse osmosis membrane will be fouled

[0006] Due to the unique pollutant composition and colloidal characteristics in PTA refined wastewater, the chemical cleaning formula and cleaning method in the prior art are not targeted, the cleaning effect is not good, and cannot meet the cleaning requirements of the PTA refined wastewater membrane treatment process