Water treatment systems and methods
AssigneeDXV Water Technologies, LLC
InventorsDiem Xuan Vuong, Michael Motherway, Curtis Roth
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Abstract
Water treatment systems and methods are provided to minimize membrane fouling and the required maintenance that results therefrom. A water treatment system includes a pressure vessel with a plurality of spaced-apart membranes disposed therein, and an impeller or other means for circulating feed water through the interior of the vessel and past the membranes. Antifouling particles (such as diatomaceous earth or activated carbon) and/or pellets can be added to the feed water inhibit membrane fouling and extend the useful life of the membranes.
Claims28
A method of treating a liquid containing membrane foulants, the method comprising:
- adding antifouling particles to the liquid, the antifouling particles having a specific surface area of 10 m2/g or more;
- supplying the liquid to a pressure vessel, the pressure vessel having an inlet, a permeate outlet, and a spiral-wound reverse osmosis or nanofiltration membrane element disposed within the pressure vessel, the membrane element having one or more membrane sheets spaced apart at a spacing of from about 1 mm to about 8 mm;
- applying a pressure differential across the spiral-wound reverse osmosis or nanofiltration membrane element so as to drive a reverse osmosis or nanofiltration process across the membrane element;
- circulating the liquid and the antifouling particles past the spiral-wound reverse osmosis or nanofiltration membrane element in the pressure vessel, wherein the antifouling particles coat membrane surfaces of the spiral-wound reverse osmosis or nanofiltration membrane element to form a protective layer over the membrane surfaces that attracts and holds membrane foulants while allowing passage of permeate through the spiral-wound reverse osmosis or nanofiltration membrane element;
- and
- collecting the permeate from the permeate outlet.
A method of treating a liquid containing membrane foulants, the method comprising:
- providing a liquid containing membrane foulants, wherein the liquid containing membrane foulants is a primary effluent from a wastewater primary treatment process;
- adding antifouling particles to the liquid containing membrane foulants, wherein the antifouling particles have a specific surface area of 10 m2/g or more, and wherein a concentration of antifouling particles in the liquid is between 1 and 20 mg/L;
- supplying the liquid containing the antifouling particles and the membrane foulants to a pressure vessel through an inlet, wherein the pressure vessel has disposed within a spiral-wound reverse osmosis membrane element, the membrane element having adjacent membrane sheets spaced apart by a spacing of from about 1 mm to about 8 mm;
- applying a pressure differential across the spiral-wound reverse osmosis membrane element;
- circulating the liquid containing the antifouling particles and the membrane foulants past the spiral-wound reverse osmosis membrane element in the pressure vessel at a cross-flow velocity of between 0.5 feet per second and 10 feet per second while applying a pressure differential across the spiral-wound reverse osmosis membrane element, wherein the antifouling particles coat membrane surfaces of the spiral-wound reverse osmosis membrane element to form a protective layer over the membrane surfaces that attracts and holds the membrane foulants while allowing passage of permeate through the spiral-wound reverse osmosis membrane element;
- and
- collecting the permeate from a permeate outlet of the pressure vessel.
Dependencies are inferred from the claim text.