• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.271-282
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• 2020

Sewage treatment plants are social infrastructure of cities. The sewage distribution rate in Korea is reaching 94% based on the sewage statistics based in the year of 2017. In Korean sewage treatment plants, use of PAC (Poly Aluminum Chloride) accounts for 58%. It contains a large amount of impurities (heavy metal) according to the quality standards, however, there have been insufficient efforts to reinforce the standards or technically improve the quality, which resulted in secondary pollution problems from injecting excessive coagulant. Also, the increase in the use of chemicals is leading to the increases in the annual amount of sewage sludge generated in 2017 and the need to reuse sludge. As such, this study aims to verify the possibility of reusing sludge by evaluating the stability of heavy metals based on the injection of coagulant mixture during water treatment which uses the torrefield wood powder and natural materials, and evaluating the sedimentation and heating value of sewage sludge. As a result of analyzing heavy metals (Cr, Fe, Zn, Cu, Cd, As, Pb, and Ni) from the coagulant mixture and PAC (10%), Cr, Cd, Pb, Ni, and Hg were not detected. As for Zn, while its concentration notified in the quality standards for drinking water is 3 mg/L, only a small amount of 0.007 mg/L was detected in the coagulant mixture. Maximum amounts of over double amounts of Fe, Cu, and As were found with PAC (10%) compared to the coagulant mixture. Also, an analysis of sludge sedimentation found that the coagulant mixture showed a better performance of up to double the speed of the conventional coagulant, PAC (10%). The dry-basis lower heating value of sewage sludge produced by injecting the coagulant mixture was 3,378 kcal/kg, while that of sewage sludge generated due to PAC (10%) was 3,171 kcal/kg; although both coagulants met the requirements to be used as auxiliary fuel at thermal power plants, the coagulant mixture developed in this study could secure heating values 200 kal/kg higher than the counterpart. Therefore, utilization of the coagulant mixture for water treatment rather than PAC (10%) is expected to be more environmentally stable and effective, as it helps generating sludge with better stability against heavy metals, having a faster sludge sedimentation, and higher heating value.

• Economic and Environmental Geology
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• v.42 no.2
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• pp.121-131
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• 2009

The distribution characteristics of heavy metals for surface sediments in east oceanic dumping area (EDA) and west oceanic dumping area (WDA) are evaluated by grain sizes, minerals, sedimentation rates and compositions of heavy metals. The mean grain sizes in EDA and WDA range from $7.95{\Phi}$ to $8.51{\Phi}$ and $7.42{\Phi}$ to $8.15{\Phi}$, respectively. These are mostly belonging to the M (mud) type. Minerals in the surface sediments consist of illite with chlorite, smectite, and kaolinite. Sedimentation rates estimated by $^{210}Pb$ method in EDA and WDA are 1.11 mm/yr$\sim$1.73 mm/yr and 1.87 mm/yr, respectively. According to the interrelationship, concentrations of Ni, Cu, Cr, and Zn are closely associated with mean grain size, Al, and Fe, whereas concentrations of Cd and Pb are poorly associated with ones. The enrichment factors of these elements are higher than 1.5, suggesting that the concentrations of Cd and Pb in the surface sediments are affected by anthropogenic sources. The $I_{geo}$-class numbers of Cd and Pb in the surface sediments are mostly classified in 2 to 4, showing moderate to strongly polluted. These numbers in EDA are higher than that of WDA, and the highest number is 4, indicative of the strongly polluted class. Our results show that the disposed wastes at EDA include mineralogical wastes, dredged materials from sewage disposals, and sludges from constructions having materials of WDA. The annual amount of oceanic dumping in EDA is double than that in WDA.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.363-373
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• 2007

To evaluate environment of farm lands using indicator insects and evaluation indices, the insect abundance of which is one of the major criteria for the evaluation of agricultural environment of farm land in urban areas and industrial complex, three sites (Ansan, Daesan, Suncheon) were designated and monitored from 2004 to 2006. The flora of agricultural land was more than urban areas and industrial complex of that in three sites. Soil, water and air pollution of urban areas and industrial complex were more serious than those of agricultural land in three sites. Overall population of insects were high from June to August in the surveyed three sites. Collected insects in agricultural land were 12 order, 106 family and 166 species, those in urban areas were 11 order, 102 family and 148 species, and in industrial complex were 11 order, 100 family and 152 species. Species and population belonging to Coleoptera was dominant in the surveyed sites. The insect diversity indices of farm land were 2.36 in agricultural land, 1.92 urban areas and industrial complex. And agricultural environment of agricultural land was good, urban areas was common and industrial complex was poor. Based on the major criteria of evaluation items, the criteria were selected as diversity index over 2.1, insect indicator Pheropsophus javanus in agricultural land, diversity index 1.5-2.0, insect indicator Nephotettix cincticeps in urban areas, diversity index below 1.5, insect indicator Pagria signata in industrial complex.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.33-42
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• 2000

Adsorption onto the surfaces of solid particles is a well known phenomenon that causes the retardation effect of heavy metals in soils. For adequate remediation of soil and groundwater contamination, it is important to investigate the mobility of heavy metals that largely depends on pH conditions in the soil water since adsorption of heavy metals is pH-dependent. In this study, we investigated the transport of Zn ion under various pH conditions in a sandy soil by conducting batch and column tests. The batch test was performed using the standard procedure of equilibrating fine fractions collected from the soil with eleven different initial $ZnCl_2$ concentrations, and analysis of Zn ion in the equilibrated solutions using ICP-AES. The column test consisted of monitoring the concentrations of soil solutions exiting the soil column with time known as a breakthrough curve (BTC). We injected respectively $ZnCl_2$ and KCl solutions with the concentration of 10 g/L as a tracer in a square pulse type under three different pH conditions (7.7, 5.8, 4.1) and monitored the flux concentration at the exit boundary using an EC meter and ICP-AES. The resident concentration was also monitored at the 10cm-depth by Time Domain Reflectometry (TDR). The results of batch test showed that ion exchange process between Zn and other cations (Ca, Mg) was predominant. The retardation coefficients obtained from adsorption isotherms (Linear, Freundlich, Langmuir) resulted in the various values ranging from 1.2 to 614.1. No retardation effect but ion exchange was found for the BTCs under all pH conditions. This can be explained by the absence of other cations to desorb Zn ion from soil exchange sites under the conditions of ETC experiment imposing blank water as leachate in steady-state flow. As pH decreased, the peak concentration of Zn increased due to the competition of Zn with hydrogen ions ($H^+$) and the concentrations of other cations decreased. The peak concentration of Zn was increased by 12.7 times as pH decreased from 7.7 to 4.1.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.175-182
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• 2022

Heavy metals can be intentionally or unintentionally introduced into plastic food utensils, containers, and packaging (PFUCP) as additives or contaminants, which can be ingested with food by humans. Here, seven-heavy metals (lead, cadmium, nickel, chromium, antimony, copper, and manganese) with toxicity concerns were selected, and risk assessment was done by establishing their migration from 137 PFUCP products made of 16 materials distributed in Korea. Migration of heavy metals was examined by applying 4% acetic acid as a food simulant (70℃, 30 minutes) to the PFUCP products. Inductively coupled plasma mass spectrometry (ICP-MS) was employed for the analysis of migrated heavy metals, and the reliability of quantitative results was confirmed by checking linearity, LOD, LOQ, recovery, precision, and expanded uncertainty. As a result of monitoring, heavy metals were detected at a level of non-detection to 8.76 ± 11.87 ㎍/L and most of the heavy metals investigated were only detected at trace amounts of less than 1 ㎍/L on average. However, antimony migrated from PET products was significantly higher than other groups. Risk assessment revealed that all the heavy metals investigated were safe with a margin of exposure above 311. Collectively, we demonstrated that heavy metals migrated from PFUCP products distributed in Korea appear to be within the safe range.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.324-333
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• 1997

The research has been made for the effects of the pollution by the abandoned coal mine drainage on the physical and chemical properties of soil, stream sediment and soil water. The soils overspreaded by the abandoned coal don't develop solum and the bulk density is $1.83g/m^3$, compared with $1.14-1.38g/m^3$ in the other forest soils. The soil pH range in coal bearing region ie, from 4.01 to 4.11 and non-coal bearing soil range is from 5.03 to 5.13. Heavy metals such as As, Cr, Ni, Mo and Ba of coal bearing soils and polluted stream sediments have larger concentration than those of non-coal content and non-polluted. Especially As and Mo concentrations are largely high in coal bearing. The relative ratios $K_2O/Na_2O$ of geochemical elements are higher in coal bearing soil and polluted stream sediments than those of non-coal bearing soils and non-polluted stream sediments as well as black shales of the Changri Formation. However, $MgO+Fe_2O_3+TiO_2/CaO+K_2O$ are the opposite trends, so that the ratios are lower in the polluted regions. The soil water pHs in the polluted regions are the strong acid(pH3.4-4.2) and buffer capacity of the polluted soil is low because canons such as $Na^+$, $K^+$, $Mg^{+2}$are leached by the acidification.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.54-63
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• 2019

As a part of the national marine ecosystem monitoring program, the temporal and spatial variation of sedimentary environment and pollution of organic matters and trace metals from four major tidal flats, i.e., Ganghwa Is., Garolim bay, Jeung Is., Suncheon bay, was investigated for 3 yerars from 2015 to 2017. The mean grain size of the sediment was $5.0-5.3{\varnothing}$ at Ganghwa Is, $4.5-4.8{\varnothing}$ at Garolim bay, $6.1-6.5{\varnothing}$ at Jeung Is, and $8.6-8.7{\varnothing}$ at Suncheon bay. The mean grain size (Mz) tended to decrease from the north (Ganghwa Is.) to the south (Suncheon bay). The ignition loss (IL) was 15.5% in Suncheon bay in 2015, which was relatively high compared to other sites, but gradually decreased over time from 8.3% in 2016 to 7.0% in 2017. In Jeung Is. and Suncheon bay, the concentration of Zn and As exceeded the threshold effect level (TEL) at some stations, but the range of trace metals in the other sites was below the level. In Jeung Is., the Mz and concentration of trace metals except Hg was positively correlated (r= 0.40-0.88, P<0.05). On the other hand, Mz was negatively correlated with trace metals (P<0.05) in Suncheon bay. The geoaccumulation index ($I_{geo}$) to evaluate contamination status of sediments for trace metal was less than 1(not contaminated) for Cu, Zn, Pb, Cd and Hg, and 2-3 (moderately to strongly polluted) for As at several stations in Suncheon bay and Jeung Is.

• The Korean Journal of Ecology
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• v.25 no.5
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• pp.335-339
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• 2002

Concentrations of Fe, Zn, Mn, Cd and Pb were determined in the tissues of sixty adult pigeons collected at six colonies in Korea, and examined correlations between elements, and between tissues in feral pigeons. As the results, we found many significant correlations between elements, and between tissues in them, A negative correlation between Cd and Fe concentrations was observed in the kidney, Cd depresses the absorption of Fe from the intestine and, in this way, affects the levels of Fe in particular tissues. This tendency could be expressed in terms of lower hemoglobin and hematocrit values because hematocrit is one of the most sensitive indicators of Cd intoxication. Zn concentrations are strongly associated with higher Cd levels in the kidney and liver. This is thought to be a reflection of the interaction known to occur between these two metals. Zn induction has been shown to antagonize a number of toxic effects of Cd. A positive correlation between Pb and Fe concentrations was detected in the livers at the Busan colony with relatively high Pb and Fe concentrations. Pb has been shown to co-accumulate with Fe in the liver by inhibiting the heme synthesis. Significant correlations, especially in toxic elements, Pb and Cd, were observed for many pairs of tissues. We suggest that these correlations between elements, and between tissues should be considered in biomonitoring for heavy metal pollution.

• Economic and Environmental Geology
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• v.46 no.5
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• pp.411-424
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• 2013

Assessment and damage reduction strategy of acidic rock drainage were conducted in a section of ${\bigcirc}{\bigcirc}$ highway construction site. The geology of the studied section consists of Icheonri sandstone and intermediate to acidic volcanic rocks. Sulfides occur as a disseminated type in sandstone and volcanics which were altered by the hydrothermal solution of granite intrusion. Volcanics and sandstone with a high content of sulfide were classified as a potentially acid rock drainage(ARD) forming rock. The drainage originated from those rocks may acidify and contaminate the surrounding area during the highway construction. Therefore, the drainage should be treated before it is discharged. A slope landslide hazard due to the ARD was also expected and the coating technology was recommended for the reduction of ARD generation as a preemptive measure before reinforcement work for enhancing slope stability such as shotcrete and anchor. According to the ARD risk analysis, those rocks should not be used as cement aggregate, but only to be used as a bank fill material of a filling-up system that allows minimal contact with rainfall and groundwater.

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.258-261
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• 2001

The paper industry produces about 6,000 ton of paper ashes yearly with by-products in Yuhan-Kimberly Ltd. The paper ashes was analyzed and evaluated for their potential as the soil acidity amendment materials. This study was conducted to investigate a reasonable amount of paper ashes for soil acidity amendment effect to be applied onto raising seedling of Calendula officinalis L. The mixed proportion of applied ashes, which was compared with agricultural lime, was treated to 0, 5, 10 and 15% (v/v) in mixed soil (pH 6.0) and the peat moss (pH 3.8) respectively. Consequently paper ashe was found to be more effective than agricultural lime at germination percentage, growth condition and in sharp initial increase of soil pH. The appropriate proportion of applied paper ash was 10% (v/v) at the soil-mix, and 15% (v/v) at the peat-moss. Soil application of paper ashes may provide supplemental quantities of K, Ca, Mg and other plant nutrients. But heavy metal concentrations in paper ash was low and should not limit application rates.