Parametric studies on the performance of cation exchange for the ammonium removal

Ion exchange performance to remove ammonium in drinking water was studied e xperimentally in batch and continuous operation systems under the various c onditions. Data were collected using commercially available strong-acid cat ion-exchange resins of Na+ and H+ types. The performance wets evaluated usi ng equilibrium concentrations for the batch system or the effluent concentr ation histories for the continuous column system as a function of time or t he solution volume passed through the experimental column until resins were exhausted. With high temperature or low initial feed concentration, ammoni um removal characteristics of the batch system increase. At the solution co ncentrations of 0.5, 1.0, and 2.0 mg/L of NH4+-N and the temperatures of 15 , 25, and 35 degreesC, the selectivity coefficients of resin were determine d between 1.38 and 1.43 for Na+ type resin, and 3.22 and 3.47 for H+ type r esin. The selectivity coefficient was correlated as a function of temperatu re using Kraus-Raridon equation. The breakthrough curves obtained from the continuous column operation give some results; i) with small column diamete r or large column height, ii) with low initial feed concentration, iii) wit h law volumetric flow rate, or iv) with high solution temperature, the ammo nium removal for the typical macroporous type resin increase. The results o f this study could be scaled up and used as a design tool for the water-pur ification systems of the drinking water treatment processes.