벤토나이트의 중금속 흡착제거에 대한 pH와 지하수 음이온의 영향

• 발행기관: 대한자원환경지질학회
• 저자명: 정찬호 정기영
• 간행물 정보: 『자원환경지질』33권 1호, 31~40쪽, 전체 10쪽
• 주제분류: 자연과학 > 지질학
• 파일형태: PDF
• 발행일자: 2000.02.28

영문 초록

Sorption characteristics of Pb, Cu, Cd, and Zn onto Ca- and Na-bentonites were investigated by the batch experiments in the condition of various pHs and concentrations of groundwater major anions (So₄2-and HCO3-), which can form a complex with heavy metals. The sorption removal of heavy metals steadily increases as pH increases. The sorption capability about heavy metals of both Ca-bentonite and Na-bentonite is in the order of Pb>Cu>Zn>Cd. The effect of pH and selectivity of heavy metals of bentonites were explained by the change of surface charge of bentonite and the speciation of heavy metals. Na-bentonite has a little higher sorption ability about heavy metals than that of Ca-bentonite. A high sorption removal of Pb in 0.1M sulfate solution may be attributed to the precipitation of PbSo₄(anglesite). However, sulfate has a slight effect on the sorption of CU, Cd and Zn. More than 99% of heavy metals were removed from the 0.1 M bicarbonate solution. However, the efficiency of sorption removal of heavy metals highly decreases in the bicarbonate solution of 10-2M to 10-4M. The speciation and saturation index calculated by the WATEQ4F program indicate that the sorption of anionic complexes such as Pb(CO₃)₂2-, Cd(CO₃)₂2-, Zn(CO₃)₂2-, Cu(CO₃)₂2- and the precipitation of the solid phases such as PbCO₃(cerrusite), ZnCO₃(smithsonite), CdCO₃(obtavite) are involved in sorption removal of heavy metals in bicarbonate solution. The sorption capability about heavy metals of bentonites in the presence of anions shows the following order: Pb>Cu Cd>Zn.

키워드

벤토나이트 중금속 흡착제거 pH 음이온 지하수 점토광물