Reduced fouling of reverse osmosis membranes
AssigneeThe Purolite Company
InventorsFrancis Boodoo, Fabio Chaves De Sousa, James A. Dale, Carmen Mihaela Iesan
Life of this patent
Estimating the term…
Abstract
The present invention provides a new water purification method and system using reverse osmosis. In particular, the present invention provides methods and water purification systems using an ion exchange resin and absorbent media for pretreatment of water being fed to a reverse osmosis treatment system, where the pretreatment reduces fouling of, or deposits or chemical attack on the membrane surfaces and passageways. Particularly, a macroporous resin having an average pore diameter in the range of 1,000 to 500,000 Angstroms and a crush strength or Chatillon value of at least 24 g/bead (710 μm bead diameter) is used.
Claims25
A method of purifying water comprising:
- a) pretreating the water by passing the water through a vessel containing a resin component, wherein the resin component comprises a highly macroporous resin having a substantial number of pores having a pore diameter in the range of 1,000 to 500,000 Angstroms and a crush strength or Chatillon value of at least 24 g/bead (710 μm bead diameter);
- and
- b) feeding the water exiting the resin component to a reverse osmosis membrane or a nanofiltration membrane to produce permeate water.
A method of treating water comprising:
- a) feeding water into a vessel containing a resin component, wherein the resin component comprises a highly macroporous resin having an average pore diameter range from 10,000 to 500,000 Angstroms and a crush strength or Chatillon value of at least 24 grams per bead;
- b) feeding the water from the resin component into a reverse osmosis system or a nanofiltration system to produce permeate water;
- and
- c) when chemical cleaning of the resin component is advised, regenerating the resin component using one solution of a single chemical or mixture of chemicals for simultaneous regeneration or rejuvenation of the resin component.
A method of treating water containing dissolved silica comprising:
- a) feeding water into a vessel containing a resin component, wherein the resin component comprises an iron-impregnant or iron-containing media which is an iron oxide attached to an ion exchange resin;
- b) feeding the water from the resin component into a reverse osmosis system, a nanofiltration system, a demineralization unit, a cooling tower, or a boiler;
- and
- c) when chemical cleaning of the resin component is advised, regenerating the resin component with an alkali solution or an alkaline and brine solution.
A water treatment system comprising:
- a resin component, which comprises
- a macroporous resin having an average pore diameter range from 1,000 to 500,000 Angstroms and a crush or Chatillon value of at least 24 g bead (710 μm bead diameter);
- and
- one or more of a polystyrene or acrylic polymer matrix-based anion exchange resin;
- an iron-impregnant or iron-containing media;
- or a strong acid cation exchange resin;
- in fluid connection to a reverse osmosis membrane or a nanofiltration membrane,
- wherein the resin component can be regenerated using a single chemical regenerant solution.
Dependencies are inferred from the claim text.