This study evaluated the biosorption properties of calcium ion using Aerobic Granular Sludge (AGS). A sequencing batch reactor was used to induce the production of Extracellular Polymeric Substances (EPS) through salinity injection, and the calcium ion adsorption efficiency was analyzed by a batch test. The EPS contents showed significant changes (104-136 mg/g MLVSS) at different salinity concentrations. The calcium ion adsorption efficiency was highest for AGS collected at 5.0% salinity, and it was confirmed that the biosorption efficiency of AGS was increased owing to the increase in EPS content. The results of the Freundlich isotherms showed that the ion binding strength (1/n) was 0.3941-0.7242 and the adsorption capacity (Kf) was 2.4082-3.3312. The specific surface area and the pore size of the AGS were 586.1 m2/g and 0.7547 nm, respectively, which were not significantly different from each other. It was confirmed that the influence of biological properties, such as EPS content, was relatively large among the factors affecting calcium ion adsorption.

Abstract
1. 서 론
2. 실험재료 및 방법
    2.1. 유입수 성상 및 실험재료
    2.2. 실험장치 및 운전조건
    2.3. Freundlich 등온흡착식
    2.4. 분석방법
3. 결과 및 고찰
    3.1. EPS 생산량
    3.2. 칼슘이온 흡착효율
    3.3. Freundlich 등온흡착식
    3.4. 비표면적 및 세공크기
4. 결 론
REFERENCES

• 김현구(주식회사 블루뱅크) | Hyun-Gu Kim (BlueBank Co., Ltd.,)
• 안대희(명지대학교 환경에너지공학과) | Dae-Hee Ahn (BlueBank Co., Ltd./Department of Environmental Engineering and Energy, Myongji University) Corresponding author