Experimental Study on the Ammonium Ion-Exchange Material and its Removal of Ammonia Nitrogen from Water

Abstract

Washed kaolin produced in Maoming, Guangzhou was used as the raw material and NaOH and NaAlO2were used as the modifiers to prepare a high-performance deaminating material by providing kaolin with sodium-type exchange groups through modification and calcination. Then the ammonia ion exchange capacity of this material was studied by means of Cation Exchange Capacity (CEC) determination. Research has also been done on the conditions for the preparation of this material, the factors that influence the result of the removal of ammonia nitrogen from water by this material, and the ammonia nitrogen removal rate of this material. In this study , an extruding-rounding process to make the powder material into 1-2mm grains and studied the forming process of the grains. Research results show that: The ammonia exchange capacity of the prepared material was greater than 70 mg NH4+-N/g. Laboratory static ammonia nitrogen experiment showed that the high-performance ammonia deaminating material could remove 90% of the ammonia nitrogen from water and were qualified for the removal of ammonia nitrogen in water treatment processes. Through the establishment of Pseudo-first reaction kinetic model and Pseudo-second reaction kinetic model of modified of kaolin absorption on NH4+, we can see that the adsorption of ammonia nitrogen in water by this ammonium ion-exchange material matches the pseudo-second-order reaction.