# US 2014/0197086 A1 · Water treatment systems and methods

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- Number: US 2014/0197086 A1
- Document ID: US20140197086A1
- Status: Published application
- Kind: A1
- Application number: 14/213,230
- Filed: 2014-03-14
- Published: 2014-07-17
- Earliest claimed: 2010-02-04
- Assignees: DXV Water Technologies, LLC
- Applicants: DXV Water Technologies, LLC
- Inventors: Diem Xuan Vuong; Michael Sean Motherway; Curtis Roth
- Web page: https://patentgrep.com/patent/US20140197086A1

## CPC

- B01D 65/06: with special washing compositions
- B01D 61/025: {Reverse osmosis; Hyperfiltration}
- B01D 61/027: {Nanofiltration}
- B01D 61/04: Feed pretreatment
- B01D 61/10: Accessories; Auxiliary operations
- B01D 61/145: {Ultrafiltration}
- B01D 61/147: {Microfiltration}
- B01D 63/082: {comprising a stack of flat membranes}
- B01D 65/08: Prevention of membrane fouling or of concentration polarisation
- C02F 1/28: by sorption (using ion-exchange C02F1/42; sorbent compositions B01J)
- C02F 1/441: {by reverse osmosis}
- B01D 65/04: with movable bodies, e.g. foam balls
- B01D 2311/04: Specific process operations in the feed stream; Feed pretreatment
- C02F 1/281: {using inorganic sorbents}
- C02F 1/283: {using coal, charred products, or inorganic mixtures containing them}
- C02F 1/36: ultrasonic vibrations
- C02F 2303/20: Prevention of biofouling
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)

## 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.

## Claims

### Claim 1

A system for treating a liquid containing membrane foulants, the system comprising:
a pressure vessel configured to hold a volume of a liquid containing membrane foulants, the pressure vessel having an inlet and a permeate outlet;
a spiral-wound reverse osmosis or nanofiltration membrane element disposed within the pressure vessel, the spiral-wound reverse osmosis or nanofiltration membrane element having one or more membrane sheets spaced apart at a spacing of from about 1 mm to about 8 mm;
a circulator configured to circulate the liquid past the spiral-wound reverse osmosis or nanofiltration membrane element in the pressure vessel; and
an antifouling apparatus configured to deliver a supply of antifouling particles to the liquid, wherein the antifouling particles are configured to coat membrane surfaces of the spiral-wound reverse osmosis or nanofiltration membrane element to form a protective layer that attracts and holds membrane foulants while allowing passage of permeate through the spiral-wound reverse osmosis or nanofiltraion membrane element.

### Claim 2 (depends on 1)

The system of claim 1, wherein the antifouling apparatus is configured to deliver the antifouling particles at a controlled rate.

### Claim 3 (depends on 1)

The system of claim 1, wherein the antifouling particles have a specific surface area of 10 m2/g or more.

### Claim 4 (depends on 1)

The system of claim 1, wherein the antifouling particles have a specific surface area of 30 m2/g or more.

### Claim 5 (depends on 1)

The system of claim 1, wherein the antifouling particles have a specific surface area of 500 m2/g or more.

### Claim 6 (depends on 1)

The system of claim 1, wherein the antifouling particles have a major dimension of 0.5 microns or more.

### Claim 7 (depends on 1)

The system of claim 1, wherein the antifouling particles have a major dimension of 1.0 micron or more.

### Claim 8 (depends on 1)

The system of claim 1, wherein the antifouling particles are configured to adsorb membrane foulants having a diameter of 1 micron or less.

### Claim 9 (depends on 1)

The system of claim 1, wherein the antifouling particles comprise diatomaceous earth.

### Claim 10 (depends on 1)

The system of claim 1, wherein the antifouling particles comprise activated carbon.

### Claim 11 (depends on 1)

The system of claim 1, wherein the one or more membrane sheets of the membrane element are spaced apart at a spacing of at least 3 mm.

### Claim 12 (depends on 1)

The system of claim 1, further comprising a supply of pellets configured to inhibit the buildup of membrane foulants on the membrane element.

### Claim 13 (depends on 12)

The system of claim 12, wherein a volume of the pellets is between about 0.5% and about 10% of the volume of the liquid.

### Claim 14 (depends on 12)

The system of claim 12, wherein the pellets have a density greater than about 1.0 g/mL.

### Claim 15 (depends on 12)

The system of claim 12, wherein the pellets have nonspherical shape.

### Claim 16 (depends on 12)

The system of claim 12, wherein the pellets have a major dimension which is less than or equal to about half the spacing between the one or more membrane sheets of the spiral-wound reverse osmosis or nanofiltration membrane element.