• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.3
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• pp.195-207
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• 2000

Organic and inorganic characteristics including bacterial cell number, enzyme activity, nutrients, and heavy metals have been monitored in twelve acrylic experimental tanks for two weeks to estimate and compare self-purification capacities in two Korean wet-land environments, tidal flat and rice field, which are possibly different with the environments in other countries because of their own climatic conditions. FW tanks, filled with rice field soils and fresh water, consist of FW1&2 (with paddy), FW3&4 (without paddy), and FW5&6 (newly reclaimed, without paddy). SW tanks, filled with tidal flat sediments and salt water, are SW1&2 (with anoxic silty mud), SW3&4 (anoxic mud), and SW5&6 (suboxic mud). Contaminated solution, which is formulated with the salts of Cu, Cd, As, Cr, Pb, Hg, and glucose+glutamic acid, was spiked into the supernatent waters in the tanks. Nitrate concentrations in supernatent waters as well as bacterial cell numbers and enzyme activities of soils in the FW tanks (except FW5&6) are clearly higher than those in the SW tanks. Phosphate concentrations in the SW1 tank increase highly with time compared to those in the other SW tanks. Removal rates of Cu, Cd, and As in supematent waters of the FW5&6 tanks are most slow in the FW tanks, while the rates in SW1&2 are most fast in the SW tanks. The rate for Pb in the SW1&2 tanks is most fast in the SW tanks, and the rate for Hg in the FW5&6 tanks is most slow in the FW tanks. Cr concentrations decrease generally with time in the FW tanks. In the SW tanks, however, the Cr concentrations decrease rapidly at first, then increase, and then remain nearly constant. These results imply that labile organic materials are depleted in the FW5&6 tanks compared to the FW1&2 and FW3&4 tanks. Removal of Cu, Cd, As from the supernatent waters as well as slow removal rates of the elements (including Hg) are likely due to the combining of the elements with organic ligands on the suspended particles and subsequent removal to the bottom sediments. Fast removal rates of the metal ions (Cu, Cd, As) and rapid increase of phosphate concentrations in the SW1&2 tanks are possibly due to the relatively porous anoxic sediments in the SW1&2 tanks compared to those in the SW3&4 tanks, efficient supply of phosphate and hydrogen sulfide ions in pore wates to the upper water body, complexing of the metal ions with the sulfide ions, and subsequent removal to the bottom sediments. Organic materials on the particles and sulfide ions from the pore waters are the major factors constraining the behaviors of organic/inorganic elements in the supernatent waters of the experimental tanks. This study needs more consideration on more diverse organic and inorganic elements and experimental conditions such as tidal action, temperature variation, activities of benthic animals, etc.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.E2
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• pp.57-68
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• 2002

Atmospheric dry deposition fluxes and size segregated concentrations of particulate metal elements were measured at four sites in Kunpo, a small city in the Seoul metropolitan area in Korea. At each site, aerosol samples were collected by dry deposition plates, a cascade impactor, and a coarse panicle rotary impactor during four sampling periods. At all sites, the average fluxes of metals measured during daytime were higher than nighttime fluxes due to higher wind speeds and higher ambient concentrations during daytime. The average fluxes of crustal elements (Al, Ca) were 1∼2 orders of magnitude higher than anthropogenic elements (As, Cd, Cu, Mn, Ni, Pb, and Zn). The daytime fluxes of Al and Ca were between 90 and 12000 $\mu\textrm{g}$ m$\^$-2/ day$\^$-1/, and the nighttime fluxes of Al and Ca were between 20 and 2200 $\mu\textrm{g}$ m$\^$-2/ day$\^$-1/. The daytime fluxes of Pb, a typical anthropogenic element, were between 20 and 160$\mu\textrm{g}$ m$\^$-2/ day$\^$-1/, and the nighttime fluxes of Pb were between ND and 100$\mu\textrm{g}$ m$\^$-2/ day$\^$-1/. Also the ambient metal concentrations during daytime were higher than nighttime. Based on a dust emission estimation study in Kunpo, it was found that dust emissions during daytime are higher than nighttime. The concentrations of crustal elements were higher than anthropogenic elements. The distributions of heavy metals were mainly in small particles (D$\_$p/ 9㎛). The fraction of crustal elements in the large particles (D$\_$p/> 9㎛) were higher than anthropogenic elements.

• Journal of Welding and Joining
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• v.32 no.6
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• pp.75-81
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• 2014

Usage of heavy metal element (Pb, Hg and Cd etc.) in electronic devices have been restricted due to the environmental banning of the European Union, such as WEEE and RoHS. Therefore, it is needed to develop the Pb-free solder plated ribbon in photovoltaic (PV) module. This study described that degradation characteristics of PV module under damp heat (DH, $85^{\circ}C$ and 85% R.H.) condition test for 1,000 h. Solar cell ribbons were utilized to hot dipping plate with Pb-free solder alloys. Two types of Pb-free solder plated ribbons, Sn-3.0Ag-0.5Cu (SAC305) and Sn-48Bi-2Ag, and an electroless Sn-40Pb solder hot dipping plated ribbon as a reference sample were prepared to evaluate degradation characteristics. To detect the degradation of PV module with the eutectic and Pb-free solder plated ribbons, I-V curve, electro-luminescence (EL) and cross-sectional SEM analysis were carried out. DH test results show that the reason of maximum power (Pm) drop was mainly due to the decrease fill factor (FF). It was attributed to the crack or oxidation of interface between the cell and the ribbon. Among PV modules with the eutectic and Pb-free solder plated ribbon, the PV module with SAC305 ribbon relatively showed higher stability after DH test than the case of PV module with Sn-40Pb and Sn-48Bi-2Ag solder plated ribbons.

• Journal of Soil and Groundwater Environment
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• v.20 no.7
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• pp.135-147
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• 2015

Remediation of metal(loid)s-contaminated sites is crucial to protect human and ecosystem. Solidification and stabilization of metal(loid)s by the binder amendment is one of the cost-effective technologies. In this study, metal (loid)s in various field-contaminated soils obtained from steel-making, metal refinery and mining tillage were immobilized by the application of single binders such as diammonium phosphate (DAP), lime, and ladle slag. The efficiency of solidification and stabilization was evaluated by Toxicity Characteristic Leaching Procedure (TCLP) and the Standard, Measurements and Testing programme of European Union (SM&T) extraction processes. In terms of TCLP extraction, the binder was effective in order of lime > DAP > ladle slag. All binders were highly effective in the immobilization of Pb, Zn, Cu, Ni, and Cd. The increased immobilization efficiency is attributed to the increase in the Step III and IV fractions of the SM&T extraction. Lime and ladle slag were highly effective in the immobilization of the metal(loid)s, however, As release increased with DAP due to competition between the phosphate originated from DAP and arsenate. A further study is needed for the better immobilization of multi metal(loid)s using binary binders.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.167-174
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• 2004

Several metalliferous and coal mines, including Myungjin, Seojin and Okdong located at the upper watershed of Okdong stream, were abandoned or closed since 1988 due to the mining industry promotion policy and thus disposed an enormous amount of mining wastes without a proper treatment facilities, resulting in water pollution in the downstream areas. AMD and waste effluents from the closed coal mines were very strongly acidic showing pH ranges of 2.7 to 4.5 and had a high level of total dissolved solid (TDS) showing the ranges of 1,030 to 1,947 mg/L. Also heavy metal concentrations in these samples such as Fe, Cu, Cd and anion such as sulfate were very high. These parameters of AMD and effluents were considered to be highly polluted as compared to those in the main stream area of the Okdong river and be major pollutants for water and soil in tile downstream area. Pollution indices of the surface water at the upper stream of Okdong river where AMD of the abandoned coal mines was flowed into main stream were in the ranges of 16.3 to 47.1. On the other hand, those at the mid stream where effluents from tailing dams and coal mines flowed into main stream were in tile ranges of 10.6 to 19.5. However, those at the lower stream were ranged from 10.6 to 14.9 These results indicated that mining wastes such as AMD and effluents from the closed mines were tile major source to water pollution at the Okdong stream areas.

• Journal of Soil and Groundwater Environment
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• v.16 no.4
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• pp.53-61
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• 2011

This study examined evaluation on stabilization of major and trace elements in tailings by various surface water-preventing materials. Six columns were filled with tailings of the Sinlim mine, then covered with tailings only, compacted soils, clay, soil-bentonite mixture, pozzolan and bentonite mat. After injection of artificial rain water, the leachate was sampled with times (3, 6, 9 and 12 pore volume) and analysed for major (Ca, Na, Mg, K) and trace elements (As, Cd, Cu, Pb, Zn) by ICP-AES. With exception to pozzolan type, the pH values of leachate from the other types became stabilized from 5.5 to 7.5, and EC (electric conductivity) of leachate from them decreased with times. For the pozzolan type, however, the pH and EC of leachate increased with time due to its alkalinity producing system. Concentrations of most major and trace elements in leachate decreased and stabilized with time. Consequently, soil-bentonite mixed cover shows the best ability of water-preventing and reducing mobility of elements in tailings site.

• Asian Journal of Atmospheric Environment
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• v.11 no.2
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• pp.122-130
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• 2017

The main purpose of the study was to clarify the properties of individual particles collected at each behavior space of a factory worker. The samplings of size-segregated ($PM_{2.1-1.1}$ and $PM_{4.7-3.3}$) indoor particles were conducted at three different behavior spaces of a factory worker who is engaged in an auto parts manufacturing plant (i.e., his home, his work place in factory, and his favorite restaurant). Elemental specification (i.e., relative elemental content and distribution in and/or on individual particles) was performed by a micro-PIXE system. Every element detected from the coarse particulate matters of home was classified into three groups, i.e., a group of high net-counts (Na, Al, and Si), a group of intermediate net-counts (Mg, S, Cl, K, and Ca), and a group of minor trace elements (P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb). The results of EF for $PM_{4.7-3.3}$ in home indicated that several heavy metals were generated from the sources within the house itself. An exceptional feature shown in the individual particles in workplace is that Cr, Mn, and Co were clearly detected in both fine and coarse particles. Cluster analysis suggested that the individual coarse particles ($PM_{4.7-3.3}$) collected at the indoor of factory were chemically heterogeneous and they modified with sea-salt, mineral, and artificially derived elements. The principal components in individual coarse particles collected at restaurant were sea-salt and mineral without mixing with harmful trace elements like chromium and manganese. Compared to the indoor fine particles of home and restaurant, many elements, especially, Cl, Na, Cr, Mn, Pb, and Zn showed overwhelmingly high net-counts in those of factory.

• The Korean Journal of Quaternary Research
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• v.19 no.2
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• pp.35-37
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• 2005

Sediment samples from five stations at the Shihwa Lake sewage outfall, west coast of Korea, were collected to evaluate the effect of the outfall on benthic foraminifera. Heavy metal (Cu and Zn) polluted eastern part of the Shihwa Lake, adjacent to the Shihwa-Banwol Industrial Complexes, shows barren or nearly barren of benthic foraminifera, and the lowest number of species both at the core top and downcore. Excepting for the barren zone, pyritized benthic foraminifera abundantly occur both at the surface and downcore sediments in the western part of the Shihwa Lake, suggesting that foraminiferal disease by anoxic bacteria. Recent intrusion of pollutants from the Shihwa-Banwol Industrial Complexes and adjacent six major streams severely polluted the Shihwa Lake as shown by the low abundance (number/10 g) of benthic foraminifera, low number of A. beccarii, low species diversity, and absence of both Elphidium spp. and ostracodes at the surface sediments compared to the downcore. Except the barren zone, both pyritized and non-pyritized Ammonia beccarii occur dominantly in the surface sediments and downcore. Elphidium spp. (either pyritized or non-pyritized) do not occur in the surface sediments of whole stations. However, they occur from the entire downcore sediments except in the eastern part of Shihwa Lake. Arenaceous foraminifera do not inhabit in the heavily polluted areas as evidenced by the occurrence of relatively deep core depth (11-50 cm). Ostracodes occur at the downcore sediments, but they do not occur at the surface sediments. Ostracodes also do not occur at the heavily polluted areas in the eastern part of the Shihwa Lake both at the surface and downcore sediments, indicating that the abundance of ostracodes also can be used for a pollution indicator.

• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.108-116
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• 2013

BACKGROUND: Certain crop-based waste materials have been recognized as cost-effective and highly efficient adsorbents for removal and recovery of different kind of heavy metals from aqueous solutions. The ability is strongly attributed to the carboxyl functional group of some pectin substances such as galacturonic acid often found in fruit peels. The present manuscript was aimed at assessing the potential applicability of banana peel for metal removal from contaminated waters. METHODS AND RESULTS: As revealed by laboratory investigations, banana peel contains pectin (10-21%), lignin (6-12%), cellulose (7.6-9.6%), and hemicelluloses (6.4-9.4%). The pectin extraction is reported to have glucose, galactose, arabinose, rhamnose, xylose, and galactouroninc acid. Several studies conducted under different conditions proved that banana peel is capable of adsorbing 5.71, 2.55, 28.00, 6.88, 7.97, and 5.80 mg/g of $Cd^{2+}$, $Co^{2+}$, $Cu^{2+}$, $Ni^{2+}$, $Pb^{2+}$, and $Zn^{2+}$, respectively, from aqueous solutions. Adsorption capacity is, however, dependent upon several factors including solution pH, dose of adsorbent and metal concentration, contact time and shaking speed. CONCLUSION(S): Since the annual world production of banana exceeds 100 million tons, about 40 million tons of banana peel (40% of total weight of the fresh fruit) remains vastly unused. Exploring a sound technology with banana peel would therefore, not only address the much needed sustainable tool for cleaning contaminated waters, but of course bring an additional value to the banana industry worldwide.

• Journal of Applied Biological Chemistry
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• v.54 no.4
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• pp.290-295
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• 2011

This study was carried out to investigate the quality of soil, irrigation water, and status of agrochemicals application in relation to good agriculture practices system in the major cultivation area of Disocorea batatas. The concentrations of heavy metals as Cd, Pb, Cu, and Zn in soils and irrigation waters were lower than those of standard level for Environmental Conservation Act of Soil and Water in Korea. The dominant weed have been appeared Digitaria sanguinalis and Portulaca oleraceamite. The dominant insect pests and plant pathogens have been appeared aphid and anthracnose. Average yearly application of pesticide was 2 to 4 times for herbicide and 4 to 6 times for plant pathogens and insect pests. In order to safety production of medicinal crops could be achieved by proper cultivation management such as minimum application of agro-chemicals, effective use of by-product fertilizer, and technology development of organic farming.