• 한국지하수토양환경학회지:지하수토양환경
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• 제20권1호
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• pp.1-6
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• 2015

The objectives of this study were to calculate the radius of influence (ROI) of well for an air-sparging (AS)/soil vapor extraction (SVE) system and to evaluate the applicability of the system applied for the remediation of the petroleum contaminated rail site. For air permeability test, three monitoring wells were installed at a location of 1.3 m, 2.3 m, 3.0 m from the extraction well. And the pressure of each monitoring well was measured by extracting air from the extraction well with the pressure and flow of $(-)2,600mmH_2O$ and $1.58m^3/min$. The ROI for an extraction well was calculated as 4.31 m. Air was injected into the injection well with the pressure and flow of $3,500mmH_2O$ and $0.6m^3/min$ to estimate the radius of influence for oxygen transfer. Oxygen concentrations of air from three monitoring wells were measured. The ROI of an injection well for oxygen transfer was calculated as 3.46 m. The 28 extraction wells and 19 injection wells were installed according to the ROI calculated. The AS/SVE system was operated eight hours a day for five months. The rail site was contaminated with the petroleum and concentrations of benzene, toluene, and xylene were over the 'Worrisome Standard' of the 'Soil Environment Conservation Act'. The contaminated area was estimated as $732m^2$ and contaminants were dispersed up to (-)3 m from the ground. During the operation period, soil samples were collected from 5 points and analyzed periodically. With the AS/SVE system operation, concentrations of benzene, toluene, and xylene were decreased from 7.5 mg/kg to 2.0 mg/kg, from 32.0 mg/kg to 23.0 mg/kg, from 35.5 mg/kg to 23.0 mg/kg, respectively. The combined AS/SVE system applied to the rail site contaminated with volatile organic compounds (VOCs) exhibited a high applicability. But the concentration of contaminants in soil were fluctuated due to the heterogeneous of soil condition. Also the effect of the remediation mechanisms was not clearly identified.

• 대한화학회지
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• 제35권4호
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• pp.355-361
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• 1991

수용액 시료 중 흔적량 수은[Hg(II)]을 공침-부선기술에 의하여 분리-농축하는 방법에 관하여 연구하였다. 물시료 1000ml에 0.1M Ce$^{3+}$ 용액 3.0 ml를 가하고, 1.0M NaOH 용액으로 pH를 11.0으로 되게 조절하여 Hg(II)를 Ce(OH)$_3$와 함께 공침시켰다. 0.1${\%}$ sodium oleate 용액 2.0 ml를 가하여 만든 소수성 침전을 질소기체로 bubbling하여 용액 표면으로 띄웠다. 뜬 침전을 감압 플라스크에 모으고 2.0M HNO$_3$ 5.0 ml 로 녹였다. 탈이온수로 용액을 묽혀 25.00 ml로 정확히 만들었다. Hg(II)의 함량을 냉증기-원자흡수 분광법으로 정량하였다. 정량과정에서 Ag$^+$, Br$^-$, I$^- $ 등의 간섭은 관찰되지 않았다. 고려대학교 서창캠퍼스의 폐수에서 Hg(II)의 분석결과는 1.98 ng/ml 이었고, 이 값에 대한 상대표준편차는 3.6${\%}$이었다. 또 이 폐수에 1.0과 2.0ng/ml의 Hg(II)를 첨가하여 분석한 회수율은 각각 95와 91${\%}$이었다. 이런 결과로부터 본 분석법이 물시료 중 흔적량 Hg(II)의 정량에 꽤 정확하고 재현성이 있음을 확인할 수 있었다.