The characteristics of heavy metal ion (Ni2+, Zn2+, and Cr3+) adsorption by zeolite synthesized from Jeju scoria using the fusion and hydrothermal method, were studied. The synthetic zeolite was identified as a Na-A zeolite by X-ray diffraction analysis and scanning electron microscopy images. The equilibrium of heavy metal ion adsorption by synthetic zeolite was reached within 60 min for Ni2+ and Zn2+, and 90 min for Cr3+. The uptake of heavy metal ions increased with increasing pH in the range of pH 3-6 and the uptake decreased in the order of Cr3+ > Zn2+ > Ni2+. For initial heavy metal concentrations of 20-250 mg/L at nonadjusted pH, the adsoption of heavy metal ions was well described by the pseudo second-order kinetic model and was well fitted by the Langmuir isotherm model. The maximum uptake of heavy metal ions obtained from the Langmuir model, decreased in the order of Zn2+ > Ni2+ > Cr3+, differing from the effect of pH on the uptake, which was mainly based on the different pH of the solutions.

Abstract
1. 서 론
2. 재료 및 방법
    2.1. 실험 재료
    2.2. 특성 분석
    2.3. 중금속 이온 흡착 실험
3. 결과 및 고찰
    3.1. 합성제올라이트의 특성
    3.2. 접촉시간의 영향
    3.3. pH의 영향
    3.4. 흡착 속도
    3.5. 흡착등온식
4. 결 론
REFERENCES

• 김정태(제주축협 축산물공판장) | Jung-Tae Kim (Jeju Livestock Research Center)
• 이창한(부산가톨릭대학교 환경행정학과) | Chang-Han Lee (Department of Environmental Administration, Catholic University of Pusan)
• 감상규(제주대학교 환경공학과) | Sang-Kyu Kam (Department of Environmental Engineering, Jeju National University) Corresponding author