• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.584-591
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• 2017

Metal removal from water has not been explained clearly by either adsorption onto the surface of absorbents or precipitation as metal hydroxides because those occur simultaneously to a certain extent. For a better understanding of the metal removal mechanisms, batch experiments were performed using soil calcined at $850^{\circ}C$ under various pH conditions for Cu, Pb, Zn, Cd, and Cr. The results showed that the metal removal efficiency with the exception of Cr decreased abruptly, even within 5 min, showing more than 90% removal. The pH of each reactant increased gradually from around 7 to 9 with time. The increases in metal removal at higher pH appear to be associated with metal hydroxides precipitation. Comparative experiments, which were carried out changing the pH by reacting with commercial activated carbon (CAC), natural yellow soil (NYS), and calcined yellow soil (CYS), showed that the pH of the CYS only increased with time. Calcination processes might lead to a change in the physical properties of the soil matrix resulting in a high pH when reacted with water. Apart from adsorption onto the surface of the absorbents, these results show that the adsorption and/or precipitation of hydroxides onto the surface of adsorbents also play important roles in regulating the dissolved metals under alkaline conditions.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.2
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• pp.25-34
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• 1999

The effects of copper on the anaerobic degradation of propionate were studied using anaerobic batch reactors. The apparent inhibitory effects of copper on the anaerobic degradation of propionate could be observed from behaviors of intermediates, ultimate methane yield(UMY) and specific methanogenic activity(SMA) There was little inhibition at the concentration of $2.5mg\;Cu^{2+}/L$. Beyond this concentration, the inhibitory effects increased with increasing dose of coppers. The 50% inhibition of UMY and SMA occurred at copper dosage of 33.8 and $24.1mg\;Cu^{2+}/gVSS$, respectively. The inhibitory effect based on the UMY was gradually reduced with the operation time dueprobably to the acclimation of microorganisms and/or binding of the added copper by ligands(and possibly ion exchange sites)contained on the cell membrane and extracellular polymer matrix whereas it based on the SMA might exclude the this phenomena. Therefore, the methodology for interpretation of inhibition data based on the SMA was more accurated than the UMY. There was no inhibitory effect in batch reactors supplemented with sulfate due to an antagonistic action of the sulfate reducing bacteria. Propionate degradation was initially retarded for copper inhibited samples but it gradually degraded afterward. Based on the mass removal considering take into account the propionate to acetate conversion, propionate degradation may appeal more affected than acetate. This result revealed that the hydrogenotrophic methanogens were the most affected by copper.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.161-166
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• 2021

This study was on leaching test(KSLT) of the aggregate for the products to evaluate the characteristics of contaminants and the possibility of contamination arising from the aggregate. On the basis pH, conductivity, turbidity, TN, TP, COD and heavy metal contents in the aggregate increased as the particle size of the aggregate was smaller. The pH appeared to be 9.9~11.4 which is relatively higher than soil, however, heavy metal has investigated within the 1 region's standard value of soil pollution standards. From the leaching test, there is strong indication that the risk of pollution due to elution of pollutants gets higher with the smaller grain size. Especially conductivity and turbidity are the potential water pollution source and recycled aggregates of 10mm or less could be a potential pollution source since it could elute soluble matters and suspended solid, but there is no proper management standard for them. As a result of evaluating water pollution possibility of the aggregate, the pH displayed in items with a very high possibility of contamination, TN and TP did in item with a low possibility of contamination and on the other hand the heavy metals did in item with a very low possibility of contamination.

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.136-145
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• 2002

A laboratory microcosm experiment was conducted to evaluate a major metal uptake route as well as chronic toxic effects of the clam, Macoma balthica exposed to Ag and Cu contaminated sediments. Twenty five clams were exposed to the sediments contaminated with four levels of Ag $Ag(0.01-0.87\mu{mol}\;g^{-1})$ and $Cu(0.75-5.55\mu{mol\;g^{-1})$ for 90 days. AVS (acid volatile sulfide) concentration in the sediments, considered as major factor controlling metal geochemistry and bioavailability, was manipulated to evaluate its effects on Ag and Cu bioaccumulation in M. balthica. Following 90-d exposure, the tissue Ag and Cu in M. balthica increased linearly with the Ag and Cu concentrations in sediments extracted with 1 N HCI (SEM, simultaneously extracted metals with AVS). The bioaccumulation of Ag and Cu in M. balthica was little influenced by difference in [SEM] - [AVS] values, suggesting a minor contribution of pore water metals to bioaccumulation. Tissue Ag and Cu concentrations directly influenced on the clearance rate and glycogen content of the clams. The clams with highest tissue Ag $(1.0\pm{0.2}\mu{mol}\;g^{-1})$ and Cu concentrations $(2.7\pm{0.3}\;\mu{mol}\;g^{-1})$ had only 18-43% of clearance of the clams exposed to uncontaminated sediments. Similarly, glycogen content of the exposed clams had a inverse relationship with tissue Ag and Cu concentrations. These results suggest that M. balthica exposed to Ag and Cu contaminated sediments accumulates metals largely by ingestion of contaminated sediments and can display chronic effects as reduced clearance rate and glycogen content.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.3
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• pp.135-143
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• 2016

We investigated the effectiveness of natural zeolite (NZ) and sand (SD) as a capping material to block the release of heavy metals (Cd, Cr, Cu, and Zn) from heavily contaminated marine sediments and stabilize these heavy metals in the sediments. The efficiency of NZ and SD for blocking trace metals was evaluated in a flat flow tank attached with an impeller to generate wave. 0, 10, 30, and 50 mm depth of NZ or SD were capped on the contaminated marine sediments and the metal concentration in seawater was monitored. After completion of flow tank experiments, sequential extractions of the metals in the sediment below the capping material were performed. The difference of pH, EC, and DO concentration between uncapped and capped condition was not significant. The release of cations including Cd, Cu, and Zn were effectively blocked by NZ and SD capping but the interruption of Cr release was observed only in 50 mm depth of SD capped condition. However, the stabilization of Cr in 50 mm depth of SD capped condition was not achieved when compared to uncapped condition. NZ and SD capping were effective for stabilizing Cd, Cu, and Zn in marine sediments. It is concluded that the use of NZ with SD as a capping material is recommended for blocking Cd, Cr, Cu, and Zn release and stabilizing them in contaminated marine sediments.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2001.05a
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• pp.173-175
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• 2001

흡착에 필요한 최적의 세라믹 볼의 소성온도는 93$0^{\circ}C$가 가장 적당하다. 공업용수 중에 용존되어 있는 유기물 및 유해성분이 제거(COD나 $BOD_{5}$)가 가능하다. Fe와 Pb의 중 금속 제거의 경우 Pb의 경우가 제거 효율이 더 크며, 이에 따른 mechanism으로 이온교환이온이 Pb의 경우 2가 양이온이기에 더욱 효율이 크고 Fe의 경우는 수화하여 구조적인 붕괴를 일으키며, 2가와 3가의 공존하므로 Pb보다 제거율이 낮다. Fe와 Pb 중금속수를 1시간 동안 제거하여 Freundlich형 등온식에 따른 계산 결과 5,10ppm에서 1/n의 수치가 2 이상을 넘지 않고 있고, 500, 1000ppm의 경우는 등온이온교환으로 할 때 1/n의 수치가 2에 근접하므로 분말의 경우에 비해 제거율이 낮지는 않다. 그러므로 경제적 이점과 재활용면에서 볼의 사용이 우수하다는 것을 알 수 있다. 장치의 용기에 비례하여 볼 때 볼의 양은 600g이 가장 적당한 양이다. 등온교환의 경우 Apatite(HAp)를 이용한 분말의 제거율 보다 약간 낮으나 분말의 경우 사용 후 취급이 용이하지 않고 2차적 오염이 예상되므로 세라믹 볼의 경우 환경친화성재료로 여러 가지의 수처라 공정에 적용이 가능할 것으로 판단된다.

• Journal of Korea Soil Environment Society
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• v.3 no.1
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• pp.31-44
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• 1998

The geochemical experiments were carried out to investigate a removal effect of heavy metals in abdndoned metallic mine wastes, and to conceive a treatment techniques of them. In order to prevent contamination, experiment appature was made of acrylic acid resin and polyethylene which resist to acid and alkali. Experiment models are devided into four groups based on the system environments, distribution patterns and a kind of filling materials. The first group is background model(model I ) which is filled with waste only and opened to air. The second one is four layer group which is subdivided into two models, opened and closed systems, and the third mix group which is subdivided into three models based on mixing ratio of filling materials and system environment like a layered group. The forth is composed of two layer model, lower one composed of waste and upper one limestone chips. Solution drained from Model Ishows a high contents of heavy metals on the all terms of experiments. Among the models, however, the closed mix model V and Ⅶ show the most effective removal of heavy metals liberated from wastes. Models having different mixing ratios of filling materials on closed systems does not affect in heavy metal removal effect. But, the distribution patterns of filling materials affect very much on removal effect of heavy metals. The closed models with same constitution ratios and distribution patterns of filling materials show more and less effective removal to the open models.

• Journal of the Korean Society of Groundwater Environment
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• v.4 no.1
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• pp.41-53
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• 1997

Geochemical data of soil and water samples were presented in order to assess the environmental impart for drinking water sites. Microscopic observation of rock samples and physical and chemical analysis of soil and water samples were undertaken. The geology of study areas are classified into three groups such as granitic rocks, meta-sedimentary rocks and sedimentary rocks. Enrichment of heavy metals derived from those rocks is not found in this study areas. Soils were analyzed for Cu, Pb, Zn, Cd and Cr using AAS extracted by HNO$_3$+HClO$_4$ and 0.1 N HCl. Heavy metal concentrations in soils are within the range of those in uncontaminated soils. In comparison of metal contents extracted by 0.1 N HCl and HNO$_3$+HC1O$_4$, less than 10% of the heavy metals are present in the exchangeable fraction. In particular, an pollution index has been proposed to assess the degree of soil contamination. Pollution index in soils are between 0.03 and 0.47 therefore, soils are not polluted with heavy metals. Deep groundwaters within granitic rocks have been evolved into Na$\^$＋/-HCO$_3$$\^$-/ type, whereas other deep groundwaters evolved into Ca$\^$2＋/-HCO$_3$$\^$-/ type. The predominance of Na$\^$＋/ over Ca$\^$2＋/ in deep groundwaters within granitic rocks is a result of dissolution of plagioclase, but for sedimentary and meta-sedimentary rocks, dissolution of calcite is a dominant factor for their hydrogeochemistry. The pH, conductivity and contents of the most dissolved ions in the water increase with depth. Shallow groundwaters, however, are highly susceptible to pollution owing to agricultural activities, considering the fact that high contents of nitrate, chloride and potassium, and high K/Na ratio are observed in some shallow groundwaters. In a thermodynamic approach, most natural water samples are plotted within the stability fields of kaolinite and smectite. Therefore, microcline and other feldspars will alter to form clay minerals, such as kaolinite and smectite. From the modelling for water-rock interactions based on mass balance equation, models accord well with behavior of the ions and results of thermodynamic studies are derived.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.387-390
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• 2006

매립장주변의 대수층 특성과 수리지화학적 특성과의 상관관계 분석은 매립장 환경 위해 요인을 평가하는데 중요한 역할을 하며 이를 위해 생활쓰레기 매립장인 금산 매립장을 대상으로 연구를 수행하였다. 대수층 매질 특성을 파악하기 위해 토양시료를 채취하여 중금속 성분 및 pH, 전기전도도, 용존유기탄소, 양이온교환능력, 유기물함량, 토양 입도분석을 수행하였고, 수리지화학적 특성 파악을 위해 수질검층 및 지하수 시료를 분석하여 매립지역의 수직 및 수평적인 분포 특성을 파악하였다. 대수층의 토양특성과 지하수 수질특성의 비교분석 결과 침출수 집수정을 기점으로 침출수의 영향을 받은 관측정의 전기전도도(EC) 측정값이 배경 지하수에 비해 상대적으로 높은 값을 보여 주었다. 입도분석 결과 상부 표토에 가까운 50cm 이내의 토양은 농경의 영향으로 심부보다 상대적으로 실트질 토양이 많고 이보다. 심부의 토양은 사질 토양으로 되어 있었다. 이러한 투수성이 좋은 사질 토양은 지하수의 이동을 비교적 쉽게 유도하기 때문에 매립장으로부터 침출수가 누출되었을 때 지하수 흐름을 따라 빠르게 이동할 수 있는 통로로 작용될 것으로 판단된다.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.9
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• pp.840-850
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• 2010

The present study was attempted to find the effects of structural properties of phosphorus on the water quality of Gyehwa reservoir in Saemangeum. Relationship of phosphorus fractions between water and sediment properties was closely examined, and a few types of phosphorus were found from the sample sediment as : Saloid-P, Al-P, Fe-P, Ca-P, Red-P and Occd-P. Saloid-P (1.4%), Al-P (0.5%), Fe-P (39.8%), Ca-P (56.6%), Red-P (0.4%), Occd-P (1.3%) were extracted in a mass basis from the sediment of Gyehwa reservoir. Approximately more than 97% of phosphorus were calcium related phosphorus (Ca-P, 56%) and iron bound phosphorus (Fe-P, 39.8%). The Fe-P closely relates with water quality of T-N (r=0.761, p<0.05), $NO_3$-N (r=0.754, p<0.05), $NH_4$-N (r=0.728, p<0.05), T-P (r=0.774, p<0.05) and $PO_4$-P (r=0.767, p<0.05) while the Ca-P did not show any consistent dependency on the water quality. On the other hand, the correlation of Ca-P with $P_2O_5$ was high with r=0.783 (p<0.05) in the sediment. The Fe-P was affected significantly on the Ignition Loss (r=0.569, p<0.05), T-N (r=0.715, p<0.05) and T-P (r=0.983, p<0.01). In the research of correlation between phosphorus fraction and heavy metals in the sediment, Ca-P did not show any specific relationships with heavy metals. The Fe-P showed a significant correlation with As (r=0.817, p<0.01), Cu (r=0.793, p<0.05), Cd (r=0.786, p<0.05), Zn (r=0.738, p<0.05), so that it can be stated that the presence of Fe-P may implicate the volume of various metallic elements.