Water treatment method

A method of regenerating a weak acid cation exchange resin, comprising the steps of:

• a) contacting said resin with a predetermined quantity of substantially a 12% (by weight) solution of citric acid;
• b) then contacting said resin with a barrier solution;
• c) then contacting said resin with a predetermined quantity of substantially a 27% (by weight) solution of sodium carbonate and,
• d) then rinsing said resin with water for a predetermined length of time.

A method of regenerating a weak acid carboxylic cation exchange resin, comprising the steps of:

• a) providing a reservoir of brine solution;
• b) providing a reservoir of citric acid solution;
• c) providing a reservoir of sodium carbonate solution;
• d) drawing citric acid solution from said citric acid reservoir and communicating a quantity of said citric acid solution through said resin;
• e) then conveying a predetermined quantity of said brine solution through said resin;
• f) then conveying a predetermined quantity of said sodium carbonate solution through said resin;
• and,
• g) then rinsing said resin with a predetermined quantity of water.

A method for regenerating a weak acid ion exchange resin comprising the steps of:

• a) providing a reservoir of brine solution;
• b) providing a reservoir of citric acid solution;
• c) providing a reservoir of sodium carbonate solution;
• d) aspirating a pre-determined quantity of said citric acid solution while aspirating a pre-determined quantity of brine solution;
• e) combining said aspirated brine solution and aspirated citric acid solution and conveying said mixture to said ion exchange resin;
• f) then aspirating a pre-determined quantity of sodium carbonate solution while concurrently aspirating a quantity of brine solution;
• g) combining said aspirated sodium carbonate solution and brine solution and conveying said combined fluid to said ion exchange resin;
• h) then rinsing said resin with water.

In a multi-tank water-softening process utilizing tanks, each containing an ion exchange resin bed, a method for regenerating a depleted ion exchange resin bed, comprising the steps of:

• a) contacting said depleted resin bed to be regenerated with a citric acid solution formed by drawing a solution of citric acid from a reservoir into a venturi means using softened water discharged by the ion exchange resin bed of another tank;
• b) then contacting said depleted ion exchange resin bed with brine solution to form a barrier;
• c) then contacting said depleted resin bed with a sodium carbonate solution by conveying sodium carbonate solution along a fluid path, from a sodium carbonate reservoir to said venturi means and using said venturi means to aspirate said sodium carbonate solution with softened water discharged by another ion exchange resin bed;
• d) then rinsing said depleted ion exchange resin bed with softened water from said another ion exchange resin bed.

A method of regenerating a weak acid carboxylic cation exchange resin, comprising the steps of:

• a) providing a reservoir of substantially a 26% (by weight) solution of sodium chloride brine solution;
• b) providing a reservoir of substantially a 12% (by weight) solution of citric acid;
• c) providing a reservoir of substantially a 27% (by weight) solution of sodium carbonate;
• d) heating said sodium carbonate reservoir to maintain said sodium carbonate solution above a predetermined temperature in order to inhibit precipitation of sodium carbonate out of said sodium carbonate solution;
• e) drawing citric acid solution from said citric acid reservoir and conveying a predetermined quantity of said citric acid solution through said resin;
• f) then drawing brine solution from said brine reservoir and conveying a predetermined quantity of said brine solution through said resin;
• g) then drawing sodium carbonate solution from said sodium carbonate reservoir and conveying a predetermined quantity of said sodium carbonate solution through said resin using a conduit means fluidly interconnecting said sodium carbonate reservoir and said resin;
• h) then flushing said conduit means;
• and,
• i) rinsing said resin with a predetermined quantity of water.

A method for regenerating a weak acid ion exchange resin comprising the steps of:

• a) providing a reservoir of brine solution;
• b) providing a reservoir of citric acid solution;
• c) providing a reservoir of sodium carbonate solution;
• d) heating said sodium carbonate reservoir to maintain said solution above a predetermined temperature in order to inhibit precipitation of sodium carbonate out of said solution;
• e) communicating a pre-determined quantity of said citric acid solution to said ion exchange resin by placing said citric acid reservoir in fluid communication with an aspirating means for a predetermined length of time while concurrently placing said brine reservoir in fluid communication with said aspirating means whereby a mixture of citric acid solution and brine solution is aspirated into through said ion exchange resin;
• f) terminating said fluid communication between said citric acid reservoir and said ion exchange resin while maintaining said fluid communication between said brine reservoir and said ion exchange resin whereby a quantity of brine solution is aspirated to and through said ion exchange rein;
• g) then communicating a pre-determined quantity of said sodium carbonate solution to said ion exchange resin by placing said sodium carbonate reservoir in fluid communication with said aspirating means for another predetermined length of time;
• h) then flushing said aspirating means;
• and,
• i) rinsing said resin with water.