Water purification process

A process for treating wastewaters to reduce the ammonia content thereof comprising the steps of:

• a. contacting wastewater, having a dissolved ammonia content, with an ion exchanger having an affinity for ammonium ions whereby ammonium ions become sorbed onto said ion exchanger;
• b. separating said ion exchanger containing sorbed ammonium ions from the wastewater and then regenerating said ion exchanger and converting the ammonium ions thereon to nitrate ions by treating the ion exchanger with a concentrated salt solution and a culture of nitrifying bacteria whereby ions from the salt solution become sorbed onto the ion exchanger while ammonium ions on the ion exchanger are displaced into solution and oxidized by the nitrifying bacteria to nitrate ions;
• said salt solution comprising a brine having a concentration of 200 to 500 milliequivalents of sodium nitrate per liter;
• and,
• c. recycling the regenerated ion exchanger for further contact with wastewater.