Purificn. of ammonium-contg. waste water

摘要

Purificn. of ammonium-contg. waste water with an ammonium concn. of 10-2000 mg NH4-N/l, comprises: (a) enriching the waste water via an ion exchange process, and regenerating the loaded ion exchanger with a regeneration soln., yielding the main portion of the waste water as pure water and the minor portion as an NH4-contg. regenerate; and (b) removal of the ammonium from the regenerate by alkalisation and desorption in a desorption appts., and recirculating the desorption outlet air, after purificn., to the desorption appts. In (a) the ammonium ions are bound to an ion exchange resin, esp. a strongly acidic cationic exchange resin or a zeolite-based resin. The ratio of waste water to regenerate is 100:1. In (b) the ammonium ions are released from the regenerate by alkalisation at a pH of 9-14. The desorption step is carried out at 40-95 deg C. The air/water ratio is 1:100-2000.