Reduced fouling of reverse osmosis membranes

摘要

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.

主权项

1. A method of purifying water containing colloidal particulates of organic matter comprising:
a) pretreating the water by passing the water through a vessel containing a resin component, wherein the resin component comprises a highly macroporous anion exchange resin having a plurality of pores having a pore diameter in the range of 4,000 to 500,000 Angstroms and a crush strength or Chatillon value of about 24 g/bead to about 50 g/bead (710 μm bead diameter); b) feeding the water exiting the resin component to a reverse osmosis membrane or a nanofiltration membrane to produce permeate water; and c) periodically regenerating the resin component by removing contaminants comprising colloidal particulates of organic matter from the resin by passing a solution of sodium chloride through the vessel, wherein the resin component reduces the organic colloidal particulate matter and the Silt Density Index (SDI) content of the water by at least 20 percent of the influent values, the solution of sodium chloride is essentially free of sodium hydroxide and the flow of water from the resin component to the reverse osmosis or nanofiltration membrane is continuous.