Method of cleaning membranes
First Claim
Patent Images
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.
9 Assignments
0 Petitions
Accused Products
Abstract
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.
647 Citations
24 Claims
-
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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
-
-
24. A method of facilitating cleaning of a porous polymeric membrane in place, the porous polymeric membrane being contained in a tank of a wastewater treatment plant including a membrane bioreactor, the method comprising:
-
providing a first cleaning solution including at least one chlorine-based oxidizing agent selected from the group consisting of chlorine, hypochlorites, chlorites, chlorates, perchlorates, and chloramines and a second cleaning solution including at least one reducing agent; and providing instructions to; contact at least a portion of the membrane with the first cleaning solution in a membrane tank for a first time period to target organic membrane foulants; introduce the second cleaning solution directly to the membrane tank including the first cleaning solution after the first time period has elapsed, a mixture of the first cleaning solution and the second cleaning solution forming an acid species from a reaction between the first cleaning solution and the second cleaning solution; recirculate the acid species through the membrane; and contact at least a portion of the membrane with the acid species for a second time period of at least about two hours to target inorganic membrane foulants; discharge a solution including the acid species after the second time period has elapsed; adjust a pH level of the discharged solution including the acid species; introduce the acid species into a head of the wastewater treatment plant after the second time period has elapsed; and mix the acid species with an incoming wastewater flow into the wastewater treatment plant.
-
Specification