• Journal of Environmental Science International
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• v.27 no.4
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• pp.241-250
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• 2018

The objective of this study was to estimate air quality trends in the study area by surveying monthly and seasonal concentration trends. To do this, the mass concentration of $PM_{10}$ samples and the metals, ions, and total carbon in the $PM_{10}$ were analyzed. The mean concentration of $PM_{10}$ was $33.9{\mu}g/m^3$. The composition of $PM_{10}$ was 39.2% ionic species, 5.1% metallic species, and 26.6% carbonic species (EC and OC). Ionic species, especially sulfate, ammonium, and nitrate, were the most abundant in the $PM_{10}$ and had a high correlation coefficient with $PM_{10}$. Seasonal variation of $PM_{10}$ showed a similar pattern to those of ionic and metallic species. with high concentration during the winter and spring seasons. $PM_{10}$ showed high correlation with the ionic species $NO_3{^-}$ and $NH_4{^+}$. In addition, $NH_4{^+}$ was highly correlated with $SO{_4}^{2-}$ and $NO_3{^-}$. We obtained four factors through factor analysis and determined the pollution sources using the United States Environmental Protection Agency(U.S. EPA) pollution profile. The first factor accounted for 51.1% of $PM_{10}$ from complex sources, that is, soil, motor vehicles, and secondary particles: the second factor indicated marine sources; the third factor, industry-related sources; and the last factor, heating-related sources. However, the pollution profile used in this study may be somewhat different from the actual situation in Korea because it was from US EPA. Therefore, to more accurately estimate the pollutants present, it is necessary to create a pollution profile for Korea.

• Journal of Environmental Science International
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• v.28 no.4
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• pp.413-422
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• 2019

The objective of this study was to estimate the trends of air quality in the study area by analyzing monthly and seasonal concentration trends obtained from sampled data. To this aim, the mass concentrations of $PM_{2.5}$ in the air were analyzed, as well as those of metals, ions, and total carbon within the $PM_{2.5}$. The mean concentration of $PM_{2.5}$ was $22.7{\mu}g/m^3$. The mass composition of $PM_{2.5}$ was as follows: 31.1% of ionic species, 2.2% of metallic species, and 26.7% of carbonic species (EC and OC). Ionic species, especially sulfate, ammonium, and nitrate, were the most abundant in the $PM_{2.5}$ and exhibited a high correlation coefficient with the mass concentration of $PM_{2.5}$. Seasonal variations of $PM_{2.5}$ showed a similar pattern to those of ionic and metallic species, with high concentrations during winter and spring. $PM_{2.5}$ also had a high correlation with the ionic species $NO_3{^-}$ and $NH_4{^+}$. In addition, $NH_4{^+}$ was highly correlated with $NO_3{^-}$. Through factor analysis, we identified four controlling factors, and determined the pollution sources using the United States Environmental Protection Agency(U.S. EPA) pollution profile. The first factor, accounting for 19.1% of $PM_{2.5}$ was attributed to motor vehicles and heating-related sources: the second factor indicated industry-related sources and secondary particles, and the other factors indicated soil, industry-related and marine sources. However, the pollution profile used in this study may be somewhat different from the actual situation in Korea, since it was obtained from US EPA. Therefore, to more accurately estimate the pollutants present in the air, a pollution profile for Korea should be produced.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.2
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• pp.151-160
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• 2014

Capacitive deionization(CDI) has many advantages over other desalination technologies due to its low energy consumption, less environmental pollution and relative low fouling potential. The objectives of this study are evaluate the performance of CDI which can be used for dissolved salts removal from sewage. To identify ion selectivity of nitrate and phosphate in multiionic solutions and adsorption/desorption performance related to applied potential, a series of laboratory scale experiments were conducted using a CDI unit cell with activated carbon electrodes. The CDI process was able to achieve more than 75 % TDS and $NO_3{^-}$, $NH_4{^+}$ removals, while phosphate removal was 60.8 % and is inversely related in initial TDS and $HCO_3{^-}$ concentration. In continuous operation, increasing the inner cell pressure and reduction of TDS removal ability were investigated which are caused by inorganic scaling and biofouling. However a relative mild cleaning solution(5 % of citric acid for calcium scaling and 500 mg/L of NaOCl for organic fouling) restored the electrochemical adsorption capacity of the CDI unit to its initial level.

• Journal of the Korean earth science society
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• v.21 no.1
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• pp.81-92
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• 2000

The purpose of this study is to elucidate the characteristic of this study is of attitudinal variation of water quality for nine representative springs in the Halla mountain region. The evolutional processes of the spring water also have been studied. Results of hydrogeochemical analyses show that Gwaneumsa spring is very high in pH. The spring waters from Yungsil, Namguksunwon, Sungpanark Oremok and Gwaneumsa which springs situated lower than 1000m in altitude are relatively high concentrations in chloride, sulphate, nitrate nitrogen and sodium ions, indicating that they are affected by surrounding pollution sources. The concentrations of bicarbonate, sulphate and hydrogen ions in spring waters increase when the precipitation increases, whereas the concentrations of nitrate nitrogen, chloride and calcium ions decrease with increasing amounts of precipitation. The magnesium, sodium and electrical conductivity are nearly independent of the precipitation. The spring waters in the Halla mountain region belong to the groups of sodium or potassium type and bicarbonate type, except the Baegrogdam and Wiseorm spring water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.424-436
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• 2013

Organic enrichment was investigated in surface sediments from the Yeoja and Gangjin Bays of Korea, which contain dense shellfish farms, in order to evaluate the contamination status and temporal changes in shellfish farming along these coasts. The degree of organic enrichment was determined using geochemical indicators (chemical oxygen demand, ignition loss, acid volatile sulfide, total organic carbon in sediments, and total nitrogen in sediments, ammonium and nitrate in pore water, and bioluminescence inhabitation for sediments). Temporal changes in organic enrichment conditions were detected by comparing our 2012 data to those previously reported from a survey conducted in 1999/2000. Organic enrichment was significantly higher in September than in May and July, in Gangjin Bay than in Yeoja Bay, and significantly higher in shellfish farms than in reference sites not used to culture shellfish. Ammonium concentrations in pore water were two orders of magnitude greater than nitrate concentrations, suggesting that these bays represent nitrogen-reducing environments.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.94-96
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• 2003

Since 1995, MOCT(Ministry of Construction and Transportation) and KOWACO(Korea Water Resources Corporation) have established the National Groundwater Monitoring Network in South Korea and also MOE(Ministry of Environment) has operated Groundwater Quality Monitoring network. Until 2001, 202 monitoring stations by MOCT and 780 monitoring wells by MOE have been constructed, measured groundwater level and analyzed water samples. Groundwater quality analysis has been conducted two times a year during last 6 years for all monitoring wells. The quality data has about 15 components including pH, COD, Count of Coliform group, and etc.. Trend analysis has been peformed for 6 components(Coliform, pH, COD, NO$_3$-N, Cl and EC) of water quality which are analyzed more than 7 times for total monitoring wells. Two test methods have been used ; Sen's test and Mann-Kendall test. These trend tests have been done at the 0.05 significance level. By the result of Sen's test, Count of Coliform group has either upward or downward trends at 4.3 percent of the monitoring points. pH does at 5.6 percent, COD does at 8.6 percent, Nitrate-Nitrogen does at 13.2 percent, Chloride does at 13.4 percent, and. EC does at 11.6 percent of the monitoring points. The exact causes of the groundwater quality trends are difficult to specify. Notable downward trends in nitrate at many monitoring points may be the result of reduction on some contamination sources. Potential causes include diminished agricultural areas, improvements in sewage treatment and a decrease in atmospheric deposition. Increase in chloride at many monitoring points may be the result of increased non-point source pollution such as road salting and runoff from sprawling paved developments and suburbs.

• Asian Journal of Turfgrass Science
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• v.21 no.2
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• pp.177-182
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• 2007

When a football field is constructed using sand medium, the fertilizer management has to be adjusted because of the low nutrient holding capacity and higher leaching rate. The objective of this study was to test the effects of slow release fertilizers on Kentucky bluegrass (Poa pratensis L.) growth in simulated sport field rootzones with PVC pipe pots. Data of turfgrass color, uniformity, growth rate, biomass above ground, and the nitrate content in the leaching solution was collected at different growing stages and during four simulated rain fall periods. The result showed that the nutrient release rate of urea was the highest and that of controlled release nitrogen fertilizer was the lowest. Effects of the controlled release nitrogen fertilizer lasted 14 days more than other lawn fertilizers and 28 days longer than regular urea with acceptable quality levels of turf. The slow release fertilizer also restrained excessive growth of the grass, reduced the times of mowing. Slow release fertilizer used in this study reduced $NO_3$-N leaching by almost 50% at the beginning of turf establishment.

• Journal of the Korean Applied Science and Technology
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• v.36 no.3
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• pp.905-914
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• 2019

In this study, The PMF model was used to identify pollutant sources and their contribution to pollution sources of $PM_{2.5}$. The contribution of A city to each source was 19.8% for Secondary Sulfate, followed by Mobile 19.5%, Industry 16.0%, Biomass Buring 14.1%, Secondary Nitrate 14.1%, Oil Combustion 11.6%, Aged Sea Salt 2.6%, Soil 2.5% and so on. Sulfate and Ammonium concentrations were the highest contributing sources in the source profile, which was analyzed to be Secondary Aerosols produced by Photochemical Reactions of gaseous precursors (SOx and ammonia gas) in the atmosphere.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.3
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• pp.193-202
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• 2003

This study was conducted to investigate the effects of the type and application level of swine manure on herbage productivity, efficiency of nitrogen utilization and environmental pollution by the leaching of nitrogen compounds in mixed grassland. The field experiment was carried out on established grassland sward growing on silt clay loam soil. Main plots were the types of swine manure, such as swine manure fermented with sawdust(SMFWS), swine manure fermented without sawdust(SMF) and swine slurry(SS), and mineral fertilizer(Urea). Subplots were the application levels of swine manure, such as 100, 200 and 400 kgN/ha, The results obtained were summarized as follows; 1. Herbage productivity, nutritive value and nitrogen yields were the highest with mineral fertilizer and followed by swine slurry(SS), and the lowest with swine manure fermented with sawdust(SMFS). As compared with dry matter(DM) yield by application of mineral fertilizer(100%), the DM percents of SMFWS, SMFS and SS were 90.6, 80,9 and 76.8%, respectively. 2. Organic matter(OM) contents of the soil were increased by the applications of swine manure. OM contents were the high set with SMFS and the lowest with mineral fertilizer. 3. The amounts of nitrate leaching by types and application levels of swine manure were the highest in the end of Aug. and early of Sep. during the seasons and ranged from 10 to 25ppm.

• Economic and Environmental Geology
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• v.45 no.1
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• pp.23-30
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• 2012

Major ions and nitrogen isotopic analyses were performed to determine the geochemical characters and to identify the source of nitrate of the shallow groundwater around agricultural field in the Youngdong area. The pH value of groundwater ranges from 60. to 8.2 (pH 7.2, mean). The average of EC, Eh and DO is 369 ${\mu}S/cm$ (70~729 ${\mu}S/cm$), 165.6 mV (29~383.2 mV), 4.3 mg/L (1.8~8.0 mg/L) respectively. The ion concentraion of groundwater was in the order of $Ca^{2+}$>$Na^{2+}$>$Mg^{2+}$>$K^{2+}$ and ${HCO_3}^-$>${NO_3}^-$>${SO_4}^{2-}$>$Cl^-$>$F^-$. Most of groundwater is Ca-$HCO_3$ type. The groundwater was affected by water-rock interaction in the shallow depth. Some groundwater is Ca-Cl or Na-$HCO_3$ (2.5%) type that was due to agricultural activities. The $NO_3$_N concetration of grondwater range from 10.2 mg/l to 26.9 mg/l, which show that this area is under nitrate pollution. ${\delta}^{15}N-NO_3$ value of the groundwater is the origins of are a combination of animal wastes and man-made fertilizers.