Processes for water and wastewater treatment, including stationary cloth media filtration
The present invention relates to stationary cloth media filtration systems and devices, as well as processes and devices for uniform flow distribution and improved cloth media filter backwashing.
1. A method of treating water or wastewater in a filtration basin using at least one filter plate comprising the steps of
providing an influent flow of water or wastewater to be treated to an influent channel which receives the influent flow, introducing said influent flow from said channel to the bottom of the filtration basin and uniformly distributing said influent flow along the length and width of the bottom of the filtration basin using an influent plenum having metering slots, said influent plenum being at the bottom of the filtration basin;
filtering said influent flow with said at least one filter plate supporting a cloth filter media said at least one said filter plate having a hollow interior;
discharging the filtered effluent with a relatively constant flow velocity and reduced head loss through at least one effluent plenum sealed from unfiltered influent, said at least one effluent plenum being in fluid communication with said hollow interior of said at least one filter plate, the filtered effluent being discharged from the filter basin through said at least one effluent plenum; and
periodically cleaning the cloth filter media supported by the at least one filter plate with suction.
2. The method of claim 1 wherein said at least one filter plate is periodically cleaned by backwashing using a backwash assembly.
3. The method of claim 2 wherein the backwash assembly includes a traveling bridge that traverses the length of the filter basin having suction headers that create suction along the cloth filter media of said at least one filter plate to remove debris trapped on said cloth filter media.
4. The method of claim 1 wherein said influent channel includes a weir extending along its length to permit adjustment of the influent flow along the filtration basin and a baffle along the length of the filtration basin to direct the influent flow to said influent plenum.
5. The method of claim 1 wherein said influent plenum and said at least one effluent plenum are generally trapezoidally shaped, complimentary to one another and located along the bottom of the filter basin.