• Journal of the Korean Geotechnical Society
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• v.22 no.11
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• pp.5-11
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• 2006

The purpose of this study was to examine the proper mixing ratio of ordinary portland cement and Bottom Ash to recycle the Bottom Ash, which is an industrial waste. After the evaluation, the compressive strength and durability were assessed using the mixture of completely weathered soil (Hwangto), weathered granite soil, and Bentonite. Then environmental friendliness of this mixed material was examined through heavy metal leaching method. It was found out that proper mixing ratio is 6:4, and that the 6% mixture quantity of completely weathered soil (Hwangto), weathered granite soil, and Bentonite is the most effective for compressive strength and durability It was also found out through heavy metal leaching method that the Bottom Ash could be below the standard of the Clean Water Law.

• Journal of the Korean GEO-environmental Society
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• v.14 no.11
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• pp.25-31
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• 2013

Civil and military firing ranges are usually contaminated with heavy metals such as lead and copper and remediation is required. Acid washing and extraction are common remediation methods. Lead contaminated firing range soil samples were collected and a preliminary study was conducted to evaluate the characteristics of the contamination and the contribution of high specific gravity particles. Ethylenediamine tetra acetic acid(EDTA) extraction was applied for the removal of heavy metal but the extraction was not feasible for the firing range soil. Even after the repeated EDTA extraction, the contamination were still over the Korean environmental standard indicating that soil particles highly contaminated with heavy metal which release the heavy metal ion even after the repeated extraction. Some colored and higher specific gravity particles were separated from the soil samples and analyzed. The colored particles have specific gravity of 2.5-6.6. The saturation ratio of Pb and EDTA was 4.9-32%. After removal of these colored particles, the sandy soil showed moderate contamination which can be treated with soil washing. This was proved with the five-level sequential extraction and TCLP tests.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1180-1185
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• 2005

Iron sand, having iron as a major component, was applied in the treatment of synthetic wastewater containing Cu(II) or Pb(II). To investigate the stability of iron sand at acidic condition, dissolution of Fe and Al was studied with variation of solution pH ranging from 2 to 4.5. Iron concentration in the extracted solution was below the emission regulation of wastewater even at a strong acidic condition, pH 2. Although an important concentration of aluminum was extracted at pH 2, the dissolution greatly decreased above pH 3. This stability test suggests that application of iron sand has little problem in the treatment of wastewater above pH 3. Adsorption capacity of Cu(II) and Pb(II) onto iron sand was investigated in a batch and a column test. In case of Cu(II), rapid adsorption was noted, showing 50% removal within 2 hrs, and then reached a near complete equilibrium after 24 hrs. Adsorption was favorable at higher pH in each metal ion and showed a near complete removal above pH 6, indicating a typical cationic-type adsorption. From the adsorption isotherm obtained with variation of the concentration of each metal ion, the maximum adsorption capacity of Cu(II) and Pb(II) was identified as 2,170 mg/kg 및 3,450 mg/kg, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.560-566
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• 2008

In this paper, the solidification behaviour and compressive strength of fly ash, cement, and waste stone powder were studied each separately and with addition of each in different proportions. And also, we assessed stabilizing ability of waste stone powder in cement which was added in fly ash. The particle size of waste stone powder was found smaller than the fly ash and cement particle sizes. Moreover, when mixing all(fly ash, cement, and waste stone powder) showed distinctive crystal structure, and improved stiffness. In case of mixing fly ash, cement and waste stone powder in different proportions, the compressive strength was exceeded to the predicted compressive strength of 10 kgf/cm$^2$. The XRD analysis showed high contents of CaO in fly ash and SiO$_2$ in case of waste stone powder sample. Heavy metal emission experiment showed the 3mg/L of Pb after 14 days of mixing 150 kg/m$^3$ of cement with the 80$\sim$100 kg/m$^3$ of waste stone powder, which is fulfilling the National Waste Management Policy.

• Economic and Environmental Geology
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• v.34 no.5
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• pp.461-470
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• 2001

The Shihung mine was restored in the early 90's after abandonment for 20 yews since 1973. Although disposed mine tailings were removed and the site was replaced by an incineration plant, still some residual mine tailings remain in the places including the old mine tailing ditposal area and the adjacent agricultural area. These residual mine tailings are prone to impose an adverse impact on the soil and groundwater and needs investigation for the potential contamination. Mine tailing samples were collected from the old tailing disposal area and the iii paddy. The porewater from the mine tailing were extracted and analysed to investigate chemical changes along the reaction path. Batch leaching tests were also carried out in the laboratory to find any supporting evidence found in the field analysis. Evidence of elemental leaching was confirmed both by the mine tailing and the porewater chemistry in them. The element concentrations of Cu, Cd, Pb, Zn in the porewater exceed the standard for drinking water of Korean government and US EPA. Leaching of heavy metals from the mine tailing seem to be responsible for the contamination. In batch leaching test. heavy metals were either continuous1y released or declined rapidly. Combining the information with porewater variation with depths and the geochemical meodeling results, most of elements are controlled by dissolution and/or precipitation processes, with some solubility controlling solid phases (Cu, Pb, Fe and Zn). Batch leaching test conducted at fixed pH 4 showed much higher releases for the heavy metals up to 400 times (Zn) and this area is becoming more vulnerable to soil and groundwater pollution as precipitation pH shifts to acidic condition.

• Economic and Environmental Geology
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• v.43 no.4
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• pp.315-332
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• 2010

All of the water and stone-dust samples with or without flocculant, in and around quarry mines, were analyzed for total concentrations of heavy metals, cyanide(CN), toxic organic compounds and organic phosphorus. Extraction experiments on stone-dust by EDTA and various pH solutions were also carried out, in order to evaluate the contaminant leaching from the long-term heaped stone-dust within quarry mines. The concentrations of $Cr^{6+}$, Hg, CN, TCE/PCE and total phosphorus in all samples (water and stone-dust) were under detection limits, confirming no environmental contamination from stone-dust in quarry mine areas. Lead and cadmium were not detected in all water samples. Copper and zinc were found in some water samples, and arsenic was detected in a few water samples. But they also showed levels much lower than the drinking water standard. Results of the extraction experiments by EDTA and pH solutions showed that Pb, Cr, Cd, Cu and Zn were leached out in less amounts or under detection limits. Arsenic was detected only at pH 3. From above results, we suggested that environmental contamination by quarry mine development is likely to be minor or negligible.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.448-452
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• 2006

This study was performed to evaluate the long-term teachability of the stabilized hexavalent chromium contaminated soils treated with chromium reducing agent and soluble phosphate. The study shows that $Cr^{6+}$ in the leachate was little detected and the remaining $PO_4-P$ concentration kept below 0.1 mg/L due to the formation of geochemically stable hexavalent chromium phosphate minerals from the reactions of labile soil $Cr^{6+}$ forms with the added soluble phosphate salt and chromium reducing agent. The results provide evidence for the potential use of the immobilization technique for the hexavalent chromium contaminated soil remediation in the near future.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.234-237
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• 2006

방부 목재는 일반 목재에 비해 사용 수명이 20-40년 정도 길기 때문에 사용이 점차 증가하고 있다 국내에서 가장 널리 사용되는 방부제는 chromate copper arsenate(CCA)이다 CCA 성분인 구리, 크롬 및 비소는 생태계 및 인체에 대한 위해성 때문에 많은 나라에서 처리 목재의 사용을 금지하거나 제한하고 있는 실정인 반면에, 국내에서의 사용은 늘어만 가고 있는 실정이다. 이 연구에서는 방부 목재를 사용하여 지은 3년 된 통나무집 한 곳과 8년 된 통나무집 두 곳에 인접한 토양시료를 채취, 분석하여 방부 목재 사용으로 인한 토양 오염도를 평가하였다. 건물에 인접한 지점부터 수평 방향으로 25cm 간격으로 100cm까지 5개의 표토 시료를 채취하였다. 또한 배경 농도를 알아보기 위해서 건물에서 조금 떨어진 곳에서 토양시료를 2개 채취하였다. 토양시료는 입도, 전기전도도, pH, 유기물 함량 등의 물리 화학적 성질에 대해 분석하였으며, CCA성분은 microwave oven을 이용하여 추출한 후 분석하였다. 0cm에서 CCA성분은 배경 농도보다. 높게 나타났다. 용출양은 3년 된 통나무집의 경우 크롬(67.2mg/kg)>구리(20.3mg/kg)>비소(4.14mg/kg)의 순으로 측정되었으며, 8년 된 통나무집의 경우 크롬(36.6mg/kg)>구리(21.3mg/kg)>비소(1.93mg/kg)의 순으로 측정되었다. 구리를 제외하고 크롬과 비소의 경우 3년 된 통나무집에서 많이 용출되는 것을 알 수 있었다. 3년 된 통나무집의 구리와 크롬은 100cm농도가 배경농도보다. 높게 나타났으며, 비소의 경우는 100cm농도가 배경농도보다. 낮게 나타났다. 이는 구리와 크롬이 100cm이상으로 이동을 한다는 것을 알려주며, 8년 된 통나무집의 경우는 크롬과 비소가 100cm이상으로 이동한다는 것을 알 수 있었다. 이 연구를 통해 CCA로 처리된 방부목재에서는 CCA성분이 용출되는 것을 알 수 있었으며, 크롬과 비소의 경우는 초기에 많이 용출되고, 구리의 경우는 꾸준히 용출되는 것을 알 수 있었다. 3년 된 통나무집이 8년 된 통나무집보다. 용출양이 더 컸으며, 이는 CCA성분이 초기에 많이 용출된다는 것을 의미한다.

• Journal of the Mineralogical Society of Korea
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• v.16 no.4
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• pp.283-293
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• 2003

Domestic water treatment plants operate the rapid and slow filtering system using the filtering sands. Most of them are composed of beach sands, which have less sorption capacity of heavy metals as well as organic contaminants. Therefore, the development of fortified functional filtering materials with high removal capacity of organic and inorganic contaminants is needed to prevent the unexpected load of contaminated source water. This study aims to test the hydrochemical change and the removing capacity of heavy metals such as Cd, Cu, and Pb on the Jumunjin sand, feldspathic sand(weathering product of Jecheon granite), feldspathic mixing sand I(feldspathic sand mixed with 10 wt% zeolite), and feldspathic mixing sand II (feldspathic sand mixed with 20 wt% zeolite). Feldspathic mixing sand I and II showed the eruption of higher amounts of cations and anions compared with the Jumunjin sand and feldspathic sand. They also showed higher eruption of Si, Ca, $SO_4$ ions than that of Al, $NO_3$, Fe, K, Mg, and P. Feldspathic mixing sand II caused higher eruption of some cations of Na, Ca, Al than feldspathic mixing sud I, which is the result controlled by the dissolution of zeolite. Jumunjin sand and feldspathic sand showed very weak sorption of Cd, Cu and Pb. In contrast to this, feldspathic mixing sand I and II showed the high sorption and removal capacity of the increasing order of Cd, Cu and Pb. Feldspathic mixing sand II including 20% zeolite showed a fortified removal capacity of some heavy metals. Therefore, feldspathic mixing sand mixed with some contents of zeolite could be used as the fortified filtering materials for the water filtering and purification in the domestic water treatment plants.

• Economic and Environmental Geology
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• v.36 no.6
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• pp.469-480
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• 2003

Laboratory leaching experiment study carried out to estimate a extent of heavy metals that could be leached out when acid rain(pH 5.0-3.0) and strong acidic solution(pH 2.5-1.0) reacted with tailings and contaminated soils from abandoned metal mines. In slightly to moderately acid conditions(pH 5.0-3.0), As, Pb and Zn dissolutions became significantly increased with decreased pH in tailing, while dissolution of these elements was very limited in contaminated soil. These results suggested that moderately acid rainwater leaches Pb, As and Zn from the tailings, while these elements would remain fixed in contaminated soil. In the pH range of 2.5-1.0(strongly acid condition), Zn, Cd and Cu concentrations of leachate rapidly increased with decreased pH in contaminated soil, while Pb, As and Co dissolutions became importantly increased in tailings. The experimental solubility of Zn. Cd and Cu was very low even at very low pH values(up to pH 1), except for CY4(Cheongyang mine). These can result from an incomplete dissolution or the presence of less soluble mineral phases. So, the solubility of heavy metals depends not only on the pH values of leachate but also on the speciation of metals associated with contaminated soils and tailings. The relative mobility of each element within failings at the pH 5.0-3.0 of the reaction solution was in the order of Pb>Zn>Cd>Co=Cu>As. In case of pH 2.5-1.0 of the reaction solution, the relative mobility of each element within contaminated soils and tailings were in the order of Zn＞Cd>Cu>Co>Pb=As for contaminated soils, and Pb>Zn>Cd>hs>Co>Cu for tailings. The obtained results could be useful for assessing the environmental effects and setting up the restoration plan in the areas.