Method of cleaning membranes

摘要

Methods for cleaning polymeric microfiltration or ultrafiltration membranes. The membrane may be contacted with a first cleaning solution including at least one oxidising agent. A second cleaning solution including at least one reducing agent may then be introduced to the membrane and first cleaning solution. The oxidising and reducing agents may undergo a neutralisation reaction to form an oxidation-neutral mixed cleaning solution. The membrane may be simultaneously cleaned during the neutralisation reaction.

主权项

1. A method for cleaning a porous polymeric membrane contained in a tank of a wastewater treatment plan including a membrane bioreactor, the method comprising:
introducing a first cleaning solution including a chlorine-based oxidizing agent selected from the group consisting of chlorine, hypochlorites, chlorites, chlorates, perchlorates, and chloramines to a tank containing the membrane; contacting at least a portion of the membrane with the first cleaning solution for a first time period; introducing a second cleaning solution including a reducing agent directly to the tank containing the membrane and the first cleaning solution after the first time period has elapsed, the second cleaning solution neutralizing an oxidizing residual of the first cleaning solution and forming an acid species from a reaction between the first cleaning solution and the second cleaning solution; soaking at least a portion of the membrane with the acid species for a second time period; and discharging a solution including the acid species from the tank after the second time period has elapsed; adjusting the pH level of the discharged solution including the acid species; introducing the discharged acid species into a head of the wastewater treatment plant; and mixing the discharged acid species with an incoming wastewater flow into the wastewater treatment plant.