• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.391-405
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• 2020

Leaching chracteristics of Andong-dam sediment was conducted for heavy metal and nutrients. Five mixed sediment samples were prepared and leaching was conducted under aerobic and anaerobic condition for 60 days. Cd, Cu, Pb, Cr, Zn, Hg, As, Fe, Mn, phosphorus, and nitrogen were analyzed at each sampling time. The leaching rate of phosphorus was higher in anaerobic condition comparing with that of under aerobic condition. Some samples showed higher than the water-quality level IV. In case of As and Cd which showed highest contamination level in the sediment, leached concentration were 0.028 mg/L and 0.003 mg/L in maximum, respectively. The leached concentration is below than the lake water quality standard of Korea. Other heavy metals including Cu, Pb, and Cr also showed similar trend. Five step sequential extraction showed that easily extractable 1-2 step portion such as ion-exchangeable and adsorbed one was less than 10% and the most of the portion was residual. For As and Cd, the residual portion were 80% and 95% respectively indicating the risk by the heavy metal leaching into the lake for a short period was not high in comparing with the contamination levels.

• Journal of Environmental Impact Assessment
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• v.31 no.5
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• pp.296-309
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• 2022

This study investigated the mobility of inorganic elements (As, Cd, Pb, and Zn) that existed as acid extractable and reducible forms in flooded soils with a pot experiment involving rice cultivation. In general, it is known that soil inorganic elements that existed as an acid extractable form which includes exchangeable, carbonates, non-specifically sorbed, and specifically sorbed have mobility. However, the result of the experiment revealed that each inorganic elements of rice roots grown from flooded soils had different characteristics. The concentrations of Arsenic existed as both forms and the concentrations of cadmium and lead existed as a reducible form in the soils showed a high causal relationship with the concentrations of those elements in the roots of rice plants. The concentrations of zinc, an essential plant element, didn't show a causal relationship. Therefore it is necessary to consider the soil's environmental characteristics such as drained/flooded condition, oxidation/reduction condition, etc. for the mobility assessment of inorganic elements. The concentrations of the reducible form of arsenic, cadmium, and lead in flooded environment such as a paddy field should be also considered because the mobility of these elements combined with Fe/Mn increases in the reduction condition.

• Journal of the Mineralogical Society of Korea
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• v.13 no.2
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• pp.73-83
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• 2000

다덕 광산 폐석내 섬아연석과 함망간탄산염 광물의 풍화현상과 그에 따른 중금속의 거동을 조사 하였다. 섬아연석은 풍화초기에 극미립 산화철의 망상구조 집합체로 교대되었으며, 후기에는 자연황이 용해중인 섬아연석과 산화철 집합체 사이에 침전되었다. 산화철 집합체에는 As가 다량 함유되어 있다. 능망간석와 함망간 방해석은 함아연산화망간의 망상구조 집합체로 교대되었으며, 함망간방해서과 함아연산화망간 사이에는 스미소나이트가 침전되었다. 선택적 용해외 X선회절분석을 이용하여 감정한 결과, 함아연산화망간은 헤테롤라이트/하이드로헤테롤라이트인 것으로 판명되었다. Zn의 일부는 규산과 결합하여 입간 공극에 월레마이트로 침전되었다. 풍화 초기에 형성되는 극미립 산화철 및 함아연산화망간의 치밀한 망상 집합체는 풍화용액의 순환을 차단하여, 모광물의 풍화 반응을 지체시키는 지화학적 장벽 역할을 하였다. 이에 따라 망상구조 내에 조성된 국지적 미환경하에서 풍화중간산물들이 침전되었다. 이상의 연구 결과로 다음과 같은 사항을 추론할 수 있다. 섬아연석의 Fe와 함망간탄산염의 Mn은 각각 산화철과 산화망간으로 침전되어 산성화에 기여하였다. 폐광석 더미내 As의 활동도는 저결정질 산화철에의 흡착에 의해 조절되며, Zn의 활동도는 미소환경조건에 따라 하이드로헤테롤라이트/헤테롤라이트, 스미소나이트, 월레마이트 등의 다양한 이차광물의 용해도에 의하여 조절된다.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.1
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• pp.36-42
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• 2003

To identify the rapacity of waste leachate absorption in Populus euramericana and Betula platyphylla var, japonica, four different treatments were applied to seedlings: leachate solution (100% leachate), 50% dilution (50% leachate: 50% water, v/v) and 25% dilution, (25% leachate: 75% water, v/v) were applied to these two species. After the experiment, concentrations of heavy metals in tree parts were analyzed by an Inductively Coupled Plasma emission spectrometer (ICP). treatment with waste leachate significantly stimulated both Populus euramericana and Betula platyphylla var. japonica biomass production relative to the water control. In addition, these species showed good absorption capacity of As, Co, Hg and Ni elements. The results of this study suggested that these two species can absorb the toxic materials through their roots and transport them to stems or leaves.

• Analytical Science and Technology
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• v.9 no.2
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• pp.210-219
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• 1996

Extraction of minerals in deionized water and elimination effect of heavy metals in water by Nohwado Quartz Porphyry were examined. When the Nohwado Quartz Porphyry was immersed and stirred in deionized water at 0.5, 1.0, 1.5 and 2.0% concentration for 3 hours, various minerals concentration of the all stirred water were suitable for potable water. Particularly, when the lead, copper, cadmium and arsenic solution were shaked with Quartz Porphyry at $20^{\circ}C$ for 24 hours, the elimination rate of each mineral was 99.5, 99.9, 95.0 and 66.5%, respectively.

• Journal of Korean Society on Water Environment
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• v.28 no.2
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• pp.197-201
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• 2012

The objective of this study was to evaluate the removal efficiency of arsenite and arsenate using composite adsorbents with various mixing ratio of recycled aluminum oxides and $TiO_2$. From batch adsorption experiments, while the removal of As(III) was almost same with 4 different composite samples in the entire pH range, the removal of As(V) was substantially increased as the weight ratio of $TiO_2$ in composite samples reduced and showed anionic adsorption characteristics. Both adsorption of As (III) and As(V) on composite samples followed pseudo-second-order adsorption equation and C-3 showed faster reaction rate for the removal of arsenic. From the adsorption isotherm experiments, Langmuir isotherm explained well and the maximum adsorption capacities of arsenic were obtained with C-1.

• Journal of Environmental Science International
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• v.27 no.3
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• pp.167-177
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• 2018

The removal characteristics of As and Se ions from aqueous solution by hexadecyl trimethyl ammonium bromide (HTMAB) modified anthracite (HTMAB-AT) were investigated under various conditions of contact time, pH and temperature. When the pH is 6, the zeta potential value of anthracite (AT) is -24 mV and on the other hand, the zeta potential value of the HTMAB-AT is +44 mV. It can be seen that the overall increase of about 60 mV. Increasing the (+) potential value indicates that the surface of the adsorbent had a stronger positive charge, so adsorption for the anion metal was increased. The isotherm data was well described by Langmuir and Temkin isotherm model. The maximum adsorption capacity was found to be 7.81 and 6.89 mg/g for As and Se ions from the Langmuir isotherm model at 298 K, respectively. The kinetic data was tested using pseudo first and pseudo second order models. The results indicated that adsorption fitted well with the pseudo second order kinetic model. The mechanism of the adsorption process showed that adsorption was dependent on intra particle diffusion model according to two step diffusion. The thermodynamic parameters(${\Delta}G^{\circ}$, ${\Delta}H^{\circ}$, and ${\Delta}S^{\circ}$) were also determined using the equilibrium constant value obtained at different temperatures. The thermodynamic parameters indicated that the adsorption process was physisorption, and also an endothermic and spontaneous process.

• Journal of Korean Society on Water Environment
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• v.27 no.4
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• pp.486-490
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• 2011

As(V) adsorption on aluminum oxide powder which was recycled from industrial wastes containing aluminum hydroxide was evaluated. Aluminum oxide powder in this study was prepared by calcinating aluminum hydroxide wastes at$550^{\circ}C$. Spectroscopic analysis indicated that the aluminum hydroxide wastes were changed to aluminum oxide by calcination. Arsenic adsorption isotherm was conducted with variation of ionic strength and multiple-ion systems using Ca(II) and Cu(II). As(V) removal showed typical anionic adsorption characteristics that the removal efficiency decreased with increasing pH in single As(V) system as well as in binary and ternary system. More than 80% of As(V) at an initial concentration of $5{\times}10^{-5}$ M was removed from aluminum oxide powder in As(V) single system. The effect of ionic strength on As(V) adsorption was negligible, which indicated the strong bonding between aluminum oxide powder and As(V). The removal efficiency of As(V) was higher in a binary system with Cu(II) than in a binary system with Ca(II).

• Journal of Korean Society of Environmental Engineers
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• v.39 no.3
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• pp.112-117
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• 2017

Ion exchange fiber, PADD was synthesized by the reaction between PAN based acrylic fiber and DETA with $AlCl_3{\cdot}6H_2O$, and was analyzed by FT-IR and SEM to investigate its characteristics. The experimental results of Cr(VI) removal by PADD were better fitted with Langmuir adsorption isotherm, and the maximum uptake value ($Q_{max}$) was calculated to be 6.93 mmol/g. The kinetic data can be well described by Lagergen pseudo-second order rate model. The Cr(VI) adsorption capacity of PADD was 4.11 mmol/g at pH 2, which shows the effect of pH changes on the removal of Cr(VI). The adsorption selectivity of Cr(VI) was higher than phosphate and As(V). Total ion exchange capacity of PADD was 4.70 mmol/g, which was measured by acid-base back titration.

• Tuberculosis and Respiratory Diseases
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• v.40 no.2
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• pp.98-103
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• 1993

Background: Inactivation of retinoblastoma gene (Rb) has been observed in a variety of human cancers. Loss of heterozygosity (LOH) of Rb which is a common mode of allelic inactivation of Rb, has been known as a frequent genetic event in small cell lung cancer but it has been detected less frequently in non-small cell lung cancer. To define the role of Rb deletion in lung cancer, we investigated the genomic DNAs of 43 non-small cell lung cancers and 1 small cell lung cancer paired with normal lung tissues obtained by thoracotomy. Methods: The genomic DNAs were obtained by the digestion with proteinase K followed by phenol-chloroform extraction method. The genomic DNAs were digested by restriction endonuclease (EcoRI), separated by agarose gel electrophoresis, transferred to nylon membrane by Southern blot transfer and then hybridized with labelled Rb 1 probe which contains. 1.4 kb sized DNA sequence containing N-terminal portion of Rb. Results: In 26 squamous cell lung cancers, 16 cases were informative after EcoRI digestion and LOH of Rb was found in 10 cases (62.5%). In 17 adenocarcinomas of lung, 11 cases were informative and LOH of Rb was found in five cases (45.4%). The analysis of clinical parameters revealed no significant differences between the two groups with or without LOH of Rb in the aspects of age, sex, degree of differentiation, stage and smoking amount. Conclusions: These results suggest that Rb inactivation is also significantly involved in the molecular pathogenesis of non-small cell lung cancer.