• Ocean and Polar Research
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• 제35권4호
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• pp.453-464
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• 2013

Heavy metals in the mangrove sediments of Chuuk and Kosrae, Federated States of Micronesia were analyzed to examine the pollution levels of heavy metals using enrichment factor (EF) and pollution load index (PLI). The mean concentrations of Cr, Ni, Cu, Zn, As, Cd and Pb in surface mangrove sediments were 642, 125, 46.9, 149, 15.6, 0.14 and 8.55 ${\mu}g$, respectively. Kosrae mangrove sediments showed the highest concentrations of Cr and Ni while Chuuk contains more of other metals such as Cu, Zn, As, Cd and Pb. Compared to those from other mangrove regions of the world, Cr, Ni and As levels in mangrove sediments from Micronesia were at higher levels whereas Cu, Zn, Cd and Pb were at lower to median levels. In core sediment of Chuuk, metal concentrations in the upper part were higher than those in the lower part. Based on the EF and PLI values, As is evaluated as the heaviest contaminant in the surface sediment from Micronesia whilst other metals (Cr, Ni, Cu, Zn, Cd and Pb) are present at slightly lesser levels.

• The Journal of Engineering Geology
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• 제18권3호
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• pp.257-262
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• 2008

In the study it was investigated the diffusion characteristics of heavy metal pollutions such as Cu, Pb, Hg and As which was the main pollution sources of soils from abandoned mines. The pollution of Cu and Pb was caused by Mine A, that of Hg was caused by Mine 3, that of Pb was caused by Mine C and that of Cu, Pb, As was caused by Mine D. Though the high concentration was detected within 100m from abandoned mines, the low concentration was detected over than 100m from abandoned mines in all heavy metals investigated except As. It means that it was very difficult to estimate the pollution level of As caused abandoned mines. The results were discussed in the concentrations of Cu, Pb and distances showed a good relationship with 0.71 and 0.68 as the coefficient of correlation, respectively. In particular the relativity of Cu to Pb as very strong with 0.84 as the coefficient of correlation. It was consistent with the chemical behavior in soils in the case of Cu and Pb. Therefore it will be a promising approach to remove Cu and Pb with estimated values in the study.

• Journal of the Korean Society of Marine Environment & Safety
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• 제23권6호
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• pp.699-709
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• 2017

We measured the grain size, total organic carbon (TOC), total nitrogen (TN), and heavy metals (As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) in order to understand the spatial distribution and pollution level of organic matter and metals in surface sediment around Goseong Bay, a shellfish farming area, Korea. The surface sediments were composed of finer sediments such as mud and clay. The concentration of TOC, TN, and heavy metals were much higher in the innermost bay than in the mouth and outside of bay. The spatial distribution of organic matter and heavy metals and C/N ratio (5-10) in sediment showed that the organic matter and heavy metals in sediment of the study region were significantly influenced by oceanic origin organic matter and anthropogenic sources, respectively. Based on the results of four assessment techniques (sediment quality guideline, geoaccumulation index, pollution load index, ecological risk index), the sediments around the Goseong Bay were a little polluted for heavy metals and the high metal concentrations in the northern region of bay could adverse impact on benthic organisms in sediment. Thus, the systematic management plan for the improvement of water and sediment environment and the concentrated monitoring of pollutants for sustainable aquaculture and seafood safety around Goseong Bay are necessary in the future.

• Applied Biological Chemistry
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• 제20권3호
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• pp.300-309
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• 1977

The information related to the heavy metal pollution in the environment was obtained from studies on the effects of pH, phosphate and soil properties on the adsorption of metal ions (Cd, Cu, Ni, and Zn) by soils. Three soil materials; soil 1 with low CEC (8.2 me/100g) and low organic carbon content (0.34%); soil 2 with high CEC (36.4 me/100g) and low organic carbon content (1.8%) and soil 3 with high CEC (49.9 me/100g) and high organic carbon content (14.7%) were used. Soils were adjusted to several pH's and equilibrated with metal ion mixtures of 4 different concentrations, each having equal equivalents of each metal ion (0.63, 1.88, 3.12 and 4.38 micromoles per one gram soil with and without 10 micromoles of phosphate per one gram soil). Reported here are the results of the equilibrium study on soil I. The rest of the results on soil 2 and soil 3 will be repoted subsequeutly. Generally higher metal ion concentration solution resulted in higher final metal ion concentrations in the equilibrated solution and phosphate had minimal effect except it tended to enhance removal of cadmium and zinc from equilibrated solutions while it tended to decrease the removal of copper and nickel. In soil 1, percentages of added metal ions removed at pH 5.10 were; Cu 97, Ni 69, Cd 63, and Zn 55, while increasing pH to 6.40, they were increased to Cu 90.9, Zn 99, Ni 96, and Cd 92 per As initial metal ion concentration increased, final metal ion concentrations in the equilibrated solution showed a relationship with pH of the system as they fit to the equation $p[M^{++}]=a$ pH+b where $p[M^{++}]=-log$[metal ion concentration in Mol/liter]. The magnitude of pH and soil effects were reflected in slope (a) of the equation, and were different among metal ions and soils. Slopes (a) for metal ions in the aqueous system are all 2. In soil 1 they were; Zn 1.23, Cu 0.99, Ni 0.69 and Cd 0.59 at highest concentration. The adsorption of Cd, Ni, and Zn in soil 1 could be represented by the Iangmuir isotherm. However, construction of the Iangmuir isotherm required the correction for pH differences.

• Journal of Advanced Marine Engineering and Technology
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• 제33권2호
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• pp.313-321
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• 2009

The construction of fiber-reinforced plastic (FRP) boats is decreasing trend since the application of international regulations on the control of marine environmental pollution, which recommended the use of environmentally friendly materials. The aluminum alloy used with material for ship is a superior to FRP. It is environmental friendly, easy to recycle, and provides a high added value to fishing boats. However, the welding for Al alloy materials have many problems, such as deformation by welding heat and effect of the working environment. In this paper, it was carried out welding by robot with welding material of ER5183 and ER5556 on 6061-T6 Al alloy for ship. The mechanical and electrochemical characteristics evaluated for specimen welded by robot. The cathodic polarization trend for the base metal and welding metal showed the effects of concentration polarization due to oxygen reduction and activation polarization due to hydrogen generation. The hardnesses of welding zone and heat affected zone are lower than that of base metal. At the result of tensile test, the specimen welded with ER5183 presented excellent property compared with ER5556.

• Korean Journal of Soil Science and Fertilizer
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• 제49권1호
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• pp.66-74
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• 2016

Environmental pollution from abandoned metal mines has been awarded as serious problem and many techniques have been applied to remediate pollutants. Main objective of this research was to evaluate efficiency of heavy metal sorption capacity of spent mushroom media (SMM) in aqueous and soil matrix. Laboratory batch experiment was conducted and 4 different heavy metals (Cd, Pb, Cu, Zn) were evaluated. In aqueous phase, all 4 heavy metals showed high reduction efficiency ranged from 60-99% and Pb showed the highest sorption efficiency. In case of soil phase, much lower sorption efficiency was observed compared to aqueous phase. The highest reduction efficiency was observed in Cd (average of 38%). With scanning electron microscopy energy dispersive detector (SED-EDS) analysis, we confirmed sorption of heavy metals at the surface of SMM. Overall, SMM can be used as sorption materials for heavy metals in both aqueous and soil matrix and more research should be conducted to increase sorption efficiency of SMM in soil.

• Environmental Analysis Health and Toxicology
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• 제24권2호
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• pp.107-117
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• 2009

Metal pollution of aquatic ecosystems is a problem of economic and health importance. Information regarding molecular responses to metal exposure is sorely needed in order to identify potential biomarkers. To determine the effects of heavy metals on chironomids, the full-length cDNA of alcohol dehydrogenase (ADH3) from Chironomus riparius was determined through molecular cloning and rapid amplification of cDNA ends (RACE). The expression of ADH3 was analyzed under various cadmium and copper concentrations. A comparative and phylogenetic study among different orders of insects and vertebrates was carried out through analysis of sequence databases. The complete cDNA sequence of the ADH3 gene was 1134 bp in length. The sequence of C. riparius ADH3 shows a low degree of amino acid identity (around 70%) with homologous sequences in other insects. After exposure of C. riparius to various concentrations of copper, ADH3 gene expression significantly decreased within 1 hour. The ADH3 gene expression was also suppressed in C. riparius after cadmium exposure for 24 hour. However, the effect of cadmium on ADH3 gene expression was transient in C. riparius. The results show that the suppression of ADH3 gene by copper exposure could be used as a possible biomarker in aquatic environmental monitoring and imply differential toxicity to copper and cadmium in C. riparius larvae.

• Proceedings of the Korea Concrete Institute Conference
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.743-747
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• 2005

In South Korea, about 900 metal mines have been abandoned, and about 88 million-t metal mine wastes have been discarded in recent years. The treatment of the tailings which are the main wastes in the abandoned metal mines becomes a social problem because they cause environmental pollution such as acidic waste water generation, groundwater contamination, and dust generation. Since almost whole quantities of the tailings have disposed by landfill now, the development of effective recycling methods for the tailings are strongly requested. It is expected that the fine tailings obtained by centrifugal separation process among the tailings can be utilized as admixture for cement. The purpose of this study is to evaluate the micro-structure of cement mortar admixed with fine tailing. Various admixtures were made of Fine tailings and 2 Types of OPC, fly-ash and blast furnace slag. The hydration reactivity of cement mortar with FT was examined by Porosity, XRD and SEM morphology analysis. The anolytical result about hardened hydrates shows that waste fine tailing help hydrates none densified due to it,s filling-space, These densified effect is concluded with improving the resistance to attack of cement mortar including waste fine tailing.

• Economic and Environmental Geology
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• 제32권1호
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• pp.53-62
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• 1999

The possibility of heavy metal pollution by contaminated roadside soils was studied under controlled conditions. The soil samples from roadside and those from a retention pond consisting of settling particles were characterized by the XRD analyses and the sequential extraction experiments. Characterization by sequential extraction, for roadside soil indicates elevate total concentrations of heavy metals. The leaching behavior of the samples under different pH and time conditions were also studied. Differences between both types of samples result mainly from the buffering effect of carbonates, present in roadside soils and lacking from settling particles. Acid leaching of the settling particles is equivalent to the sum of FI+FII+FIII, while the amounts leached from roadside soil are lower probably from kinetic reasons. The buffering effects of carbonates were found to greatly delay the onset of the leaching reactions and the extent of dissolution in most metals except for Ca and Mn. The study of leaching kinetics at pH of 6.5 and 5 showed that Cd and Zn reached the maximum possible concentration within 3 days, while Pb did not show any sign of dissolution at both ph values. The absolute amounts of dissolved Cd and Zn increased by 7 to 9 times by decreasing the pH from 6.5 to 5, indicating slightly acidified rain may result in significant metal dissolution. As deduced from both sequential extraction and leaching experiments, the relative mobility of heavy metals is found to be : Mn=Cd>Zn>>Pb>Fe, in spite of large differences in heavy metal contents and localizations.

• Environmental Engineering Research
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• 제24권3호
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• pp.427-433
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• 2019

Sakarya is famous for cucurbit productions in Turkey and cucurbits can grow as big as 560 kg of weight per fruit in its agricultural areas. There is no or limited information about contaminant levels and profiles of the agricultural fields in Sakarya. The purpose of this study is to investigate the levels of polycyclic aromatic hydrocarbons (PAHs) (naphthalene, phenanthrene, pyrene, and fluoranthene) and heavy metal (As, Cd, Cu, Cr, Ni, Pb, Zn) concentrations of the selected fields. Total 33 soil samples were collected from 12 counties of Sakarya where both cucurbits have been produced and organochlorine pesticides have been applied to the fields for more than 30 y during the historical plantation periods. Heavy metal and PAH contents in the soil samples were measured by an Inductively Coupled Plasma Emission Spectroscopy and a Gas Chromatography-Mass Spectrometry. The highest phenanthrene, pyrene, and fluoranthene concentrations were measured as 63.50 ng/g, 134.34 ng/g, 140.0 ng/g, respectively in the soil samples from Geyve County. Cu, Ni, and Cr concentrations were measured as 108.2 mg/kg, 219.9 mg/kg, and 173.1 mg/kg, respectively in Geyve's samples which were also the highest and 2-7 times more than the limit values given in the Turkish Soil Pollution Control Regulation. Precautions need to be taken for Sakarya's agricultural fields which are an important milestone of Turkey's cucurbit and fruit productions since the contaminants can be accumulated in the fruits and edible parts of the plants.