METHOD AND APPARATUS FOR MITIGATING BIO FOULING IN REVERSE OSMOSIS MEMBRANES
A method and apparatus for reduction of biofouling on reverse osmosis membranes is provided. One embodiment provides a charged filter surrounding a cathode that is, in turn, surrounded by an anode. A plurality of these charged filters may be included in a larger filtration system that may be included in a typical reverse osmosis system.
1 . A filter system, comprising:
a housing having an interior and an exterior,
a filter cartridge on the interior of the housing, said filter cartridge comprising a cylindrical filter material, said filter material surrounding a cathode, and said filter material surrounded by an anode plate;
wherein the housing comprises an inlet, an outlet, a drain, and a vent.
2 . The filter system of claim 1 , wherein the filter system includes multiple filter cartridges depending on the design flow.
3 . The filter system of claim 1 , wherein the filter cartridge is at least 30″ in length.
4 . The filter system of claim 1 , wherein the filter cartridge is between 30″-40″ in length.
5 . The filter system of claim 1 , wherein the filter cartridge handles a wide range of flow rates up to 1000 m 3 /hour
6 . The filter system of claim 1 , wherein the cathode is a cylindrical rod.
7 . The filter system of claim 1 , wherein the filter material is positively charged.
8 . The filter system of claim 1 , wherein the filter material is negatively charged.
9 . The filter system of claim 1 , further comprising a power supply in a circuit with the cathode and the anode.
10 . The filter system of claim 9 , wherein the power supply is mounted on the housing.
11 . The filter system of claim 1 , wherein the housing is constructed of a material selected from the group consisting of fiber reinforced plastic, rubber-lined carbon steel, and stainless steel.
12 . A filter system, comprising:
a housing having an interior and an exterior,
a plurality of filter cartridges on the interior of the housing, each of said filter cartridges comprising a cylindrical filter material, said filter material surrounding a cathode, and said filter material surrounded by an anode plate;
wherein the housing comprises an inlet, an outlet, a drain, and a vent.
13 . The filter system of claim 12 , wherein the filter system has a water flow rate capacity, and wherein the water flow rate capacity increases proportionately to the number of filter cartridges in the filter system.
14 . The filter system of claim 12 , wherein the filter cartridges operate in parallel.
15 . A method for reducing biofouling on a reverse osmosis membrane, comprising:
treating water comprising biofoulants with an ultrafiltration membrane; and
after treating the water with an ultrafiltration membrane, treating the water with a charged filter system.
16 . The method of claim 15 , wherein said charged filter system comprises:
a housing having an interior and an exterior,
at least one filter cartridge on the interior of the housing, said filter cartridge comprising a cylindrical filter material, said filter material surrounding a cathode, and said filter material surrounded by an anode plate, wherein the housing comprises an inlet, an outlet, a drain, and a vent; and
a power supply in communication with the cathode and the anode.
17 . The method of claim 15 , wherein the water comprises an amount of polysaccharides, and wherein after treatment with the charged filter system the amount of polysaccharides is reduced.
18 . The method of claim 15 , wherein the water comprises an amount of bacteria, and wherein after treatment with the charged filter system the amount of bacteria is reduced without using any oxidants.
19 . The method of claim 15 , wherein there is no difference in oxidation reduction potential (ORP) value of water across the filter system.
20 . The method of claim 15 , further comprising regenerating at least one filter in the charged filter system in-situ by changing polarity of the charge and draining previously adsorbed material.