| US 7,459,083 B1 | ||
| Method for controlling fouling of a membrane filter | ||
| Sun-Nan Hong, Cary, N.C. (US); Hong W. Zhao, Raleigh, N.C. (US); and Richard W. DiMassimo, Raleigh, N.C. (US) | ||
| Assigned to I. Kruger Inc., Cary, N.C. (US) | ||
| Filed on May 07, 2007, as Appl. No. 11/745,120. | ||
| Int. Cl. C02F 3/00 (2006.01) | ||
| U.S. Cl. 210—620 [210/629; 210/741; 210/797] | 9 Claims |
| 1. A method for controlling fouling of a membrane filter in a biological wastewater treatment process, comprising:
directing wastewater influent into one or more reactors and treating the wastewater;
directing the wastewater into and through one or more membrane tanks having one or more membrane filters therein;
filtering the wastewater by directing the wastewater through the membrane filters and producing a permeate;
cleaning the membrane filters with air scouring;
measuring trans-membrane pressures and a liquid level in at least one of the membrane tanks;
executing multiple control cycles to control scouring air flow rate, flux, permeation phase duration, and relaxation phase
duration;
in at least one of the control cycles, optionally adjusting each of scouring air flow rate and flux as a function of the measured
trans-membrane pressures and of the measured liquid level in the membrane tank;
in at least one of the control cycles, optionally adjusting each of relaxation phase duration and flux as a function of the
measured trans-membrane pressures and of the measured liquid level in the membrane tank; and
in at least one of the control cycles, optionally adjusting each of flux and permeation phase duration as a function of the
measured liquid level in the membrane tank.
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