The ammonium-ion exchange characteristics of natural zeolite were investigated to remove NH4(+)-N. The effect of water temperature, pH and competitive cationic concentrations on the exchange capacity was examined. The ammonium-ion exchange capacity was found to be 2.083 meq. NH4(+)-N/g-zeolite, and it was not influenced by water temperature; however, with the increase of pH from 7 to 9, the capacity was reduced up to 4.2%. The separation factor was increased up to 24% with increase in the water temperature from 25 ℃ to 55 ℃. When the competitive cationic concentrations, such as K(+), Ca(2+), and Mg(2+), increased from 10 to 150 mg/L in the di-component systems, the selective ammonium-ion exchange capacity was decreased up to 28%. With the effect of competitive ion, the selectivity sequence was K(+)>Ca(2+)>Mg(2+). The column test has shown that the natural zeolite had self-sharpening of ion exchange independent of flow rate in the range of 5 to 15 BV/h. It indicated that NH4(+)-N from the effluents of biological treatment processes can be removed by usage of the domestic natural zeolite.

천연 제올라이트를 이용한 NH4(+)-N 제거 특성을 살펴보기 위해 수온, pH 및 공존 양이온이 이온 교환능에 미치는 영향을 살펴보았다. 우선 제올라이트의 NH4(+)-N 이온 교환능은 2.083 meq. NH4(+)-N/g-zeolite이었으며, 수온에 대한 영향은 없었다. 그러나 pH가 7에서 9로 증가함에 따라 4.2%가 감소하였다. 분리 인자는 수온이 25 ℃에서 55 ℃로 증가할 동안 24%의 증가를 보였다. 또한 K(+), Ca(2+) 및 Mg(2+) 등의 양이온이 존재할 경우 NH4(+)-N 이온 교환능이 28% 감소하였으며, 공존 양이온의 효과는 K(+)>Ca(2+)>Mg(2+)의 순으로 나타났다. 컬럼 시험에서는 유속이 5-15BV/h사이에서 이온 교환은 self-sharpening의 형태를 보여주었다. 이러한 결과는 생물학적 처리수의 유출수로부터의 NH4(+)-N 제거효율에 가능성이 있음을 보여주고 있다.