• Nuclear Engineering and Technology
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• 제54권5호
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• pp.1597-1605
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• 2022

A porous silica-based adsorbent was prepared by impregnating the pores of a silica support with the extractant 1,3-[(2,4-diethylheptylethoxy)oxy]-2,4-crown-6-calix[4]arene (Calix[4]arene-R14) and an additive agent 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (C₂mim ⁺ NTf^-₂) as the materials to remove cesium(I) (Cs⁺) ions from seawater. The as-prepared adsorbent showed excellent adsorption performance toward Cs⁺ ions, with adsorption equilibrium reached within 2 h and an adsorption amount of 0.196 mmol/g observed. The solution pH, temperature, and the presence of coexisting metal ions were found to have almost no effect on Cs⁺ adsorption. The adsorption mechanism was considered to proceed via ion exchange between Cs⁺ and C₂mim⁺. In addition, the particle-induced X-ray emission analysis results further clarified that the adsorbed Cs⁺ ion species on the adsorbent was in the form of both CsCl and CsBr.

• 자원리싸이클링
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• 제13권4호
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• pp.23-31
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• 2004

수산물 처리시 폐기물로 발생하는 Undaria pinnatifida 를 $Pb^{2+}$ 가 함유된 폐수의 흡착처리시 흡착제로 활용하는 방안을 검토하였다. 성분분석 결과, Undaria pinnatifida는 주로 탄화수소화합물로 구성되어 있었으며 비표면적이 상당히 높아 흡착제로서의 잠재적 활용도가 큰 것으로 파악되었다. Undaria pinnatifida 입자의 Electrokinetic Potential은 pH 8 부근에서 음의 최대값을 보였으며 전 pH 범위에 걸쳐 음으로 하전되어 양이온의 흡착에 적합한 것으로 검토되었다. $Pb^{2+}$는 실험조건에서 반응개시 수 분 이내에 대부분이 흡착되었으며 평형에 도달하는 시간은 약 30분 정도인 것으로 나타났다. 또한, Undaria pinnatifida 표면에 대한 $Pb^{ 2+}$의 흡착은 Freundlich Isotherm 을 따르는 것으로 관찰되었으며 발열반응의 특성을 확인하였다. 산에 의한 흡착제의 전처리는 흡착능을 향상시켰으나 염기로 전처리할 경우에는 오히려 흡착능이 저하되었다. Undaria pinnatifida 표면에 존재하는 작용기들과 $Pb^{ 2+}$ 와의 Organometallic Complex 형성이 $Pb^{ 2+ }$의 흡착에 주요하게 작용하는 것으로 파악되었으며, 경쟁적 흡착질의 존재, ionic Strength 의 변화, 그리고 착화합물제가 수중에 공존할 경우 $Pb ^{2+}$ /의 흡착성이 상당한 영향을 받는 것으로 관찰되었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권1호
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• pp.30-40
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• 2018

To evaluate potential impacts of shallow groundwater by the leachate from buried carcass, we investigated hydrochemical characteristics of both leachate and shallow groundwater from monitoring wells and surrounding shallow groundwater wells in an area potentially affected by pig carcass burial. The hydrochemical survey was conducted before and after the relocation of a burial pit. The leachate samples and the groundwater affected by leachate showed the hydrochemistry of $Ca-HCO_3$ type with high $NH_4{^+}$ concentrations, while unaffected groundwater was mostly the $Ca(Na)-Cl+NO_3$ type due to pervasive impacts from agrochemicals. The results of factor analysis on hydrochemical data showed the followings: 1) contamination of groundwater from agro-livestock farming and livestock burial are coexisting in the study area, 2) among ionic species, $HCO_3{^-}$, $NH_4{^+}$, $NO_3{^-}$ and Mn are very useful to differentiate the groundwater contamination from leachate, and 3) groundwater contamination by leachate has been recognized around the monitoring wells even after the relocation of a burial pit, likely due to residual contaminants in surrounding soils. Therefore, it is suggested that continued monitoring of groundwater contamination should be conducted after the relocation of carcass burial pits.