• Clean Technology
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• v.5 no.1
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• pp.78-85
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• 1999

In the Kimchi manufacturing industry that has recently been on its greatest growth, the rinsing process for salt-pickled Chinese cabbage in a brining step generates a vast amount of rinsing wastewater containing salts, colloids, and organics released from the raw material. In this study, the experimental method was developed to optimize the rinsing water consumption and thus to minimize the rinsing wastewater generation. The continuous counter-current rinsing basin in the actual plant was simulated through the lab-scale three batch-wise rinsing tanks. Rinsing efficiencies for the brined cabbage from the same brining tank were almost in the same level, whereas those varied substantially from source to source in the raw Chinese cabbage provided. When rinsing water used were decreased from 3.3 L/head to 2.7 L/head, no significant change was observed with respect to COD, turbidity, conductivity, $Na^+$, and $Cl^-$ concentrations in the extracted solution of the rinsed cabbage. However, the quality of the extracted solution was badly deteriorated as the amount of rinsing water used dropped down to below 2.7 L/head. The reduction of rinsing water up to 18% was proved to be possible without any negative effect on the quality of the product, Kimchi.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.743-754
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• 2000

Model parameters of the WASP5 applied to Saemanguem lake were estimated. The methodology is based on grouping water quality constituents and relevant parameters and successively estimating each group of parameters by a trial-and-error procedure. Chlorophyll-a, nitrogen cycles, phosphorus cycles, BOD and DO were simulated at the complexity level 4. The Saemangeum basin divided into a number of unit sub-watershed. And a water budget model analysis with 22 years from 1975 to 1996 year was examined. In this paper, input data at upstream boundaries of model was made to determine seasonally-averaged flow rate through water budget analysis. Calibration and verification of the model were used seasonal average of water quality measurements in 1997 and 1998 years. Grouping water quality constituents and associated parameters proved to be efficient in estimating a number of model parameters. From the results of model calibration and verification, it was found that quantitative evaluations of nonpoint source for organic matters are essential.

• Journal of the Korean Society of Groundwater Environment
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• v.7 no.3
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• pp.116-124
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• 2000

Geochemical and isotopic analyses were carried out to investigate hydrochemical characteristics, source of carbon species in the carbonated waters in South Korea. Most Korean carbonated waters from different geologic settings are characterized by a Ca-HCO$_3$type with a relatively low pH range from 5.3 to 6.3 (avg. 6.0). The concentrations of cations and anions in the carbonate waters are in the order of Ca$^{2＋}$>Na$^{＋}$>Mg$^{2＋}$>Si$^{4＋}$>Fe$^{2＋}$>K$^{＋}$ and HCO$_3$$^{－}$>SO$_4$$^{2－}$>Cl$^{－}$, respectively. The HCO$_3$$^{－}$ ion is more enriched in the carbonated water from the sedimentary rock and granitic rock of Mesozoic age in the Gyungsang basin(GII) and the Precambrian metamorphic rock and Jurassic granitic rocks of the Gyunggj massif in the Gangwon province(GⅠ) than those of the meta-sedimentary rock and granite in the Ogcheon zone(GⅢ). Based on the oxygen and hydrogen isotopic data, the carbonated waters are derived from the meteoric water, showing apparent latitude and altitude effects. The $delta$$^{13}$C values of carbon species in the carbonated water are in between -6.23 and 0.0 $textperthousand$, suggesting inorganic source of carbon originated from the carbonate mineral and carbonate rock in the aquifer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3336-3344
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• 2014

The purpose of this study is small scale coagulation module is developed and demonstrated through a lab-scale test. Recent as a sewage treatment rate increases, have heightened the interest in the necessity on the nonpoint source and developing a small processing unit has been increased. Coagulation sedimentation module in this study is additional growth of floc through swirling in the outside zone, reduction of microstructure floc number and the internal settling zone through vertical/level flow complex sedimentation method after the coagulation process precipitation method as an effective high separation efficiency can be divided was also assessed. Coagulation sedimentation module can increase the load factor was 4.4 times compared to conventional clarifier base on the same volume and surface area through vertical/level flow. In this study, this process was selected formation and maintenance of swirling and uniform flow distribution in the internal settling zone as an important design factor, to derive its FLUENT was used to characteristics of the flow model. Through the simulation of swirling, influent velocity, dimensions of external basin, hopper depth of bottom cone was determined and through analysis of velocity distribution, flow distribution detailed specifications are derived like as diameter and number of effluent hole. Lab-scale($120{\ell}/hr$) test results, influent of 300~800 NTU to less than 10 NTU without polymer feeding was able to operate in the 20minutes retention time(surface loading rate $37.3m^3/m^2$-day), and through analysis FLUENT the possibility of using design parameters were derived.

• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.238-246
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• 2019

Objective: The purpose of this study was to investigate the distribution of mineral components, health and taste index for water supply plants, spring water located in northern Gyeonggi area and bottled waters in market to analyze Ca, K, Mg Na, Si, $F^-$ and $SO_4{^{2-}}$. Method: The samples were source and tap water in 15 water supply plants over 9 river basin, 172 spring water and 20 bottled water. The Ca, K, Mg Na and Si were analyzed by ICP-OES. The $F^-$ and $SO_4{^{2-}}$ were determined by Ion Chromatograph. Then, taste and health index were calculated using Hashimoto equation. Results: The average concentration of major minerals showed in same order of Ca > Na > Mg > K for all kinds of drinking water from water supply plants, spring waters and bottled waters. Total concentration of major minerals (Ca, K, Mg, Na) was calculated that showed 26.79 mg/L of tap water, 21.81 mg/L of spring water, 32.94 mg/L of bottled water on average. So, the spring waters indicated the lowest minerals sum. The tap water from water supply plants was categorized to Group I, II for 33.3, 44.4% according to K-index and O-index. Otherwise, spring water was classified as Group I, II for 44.0, 46.3%. Conclusion: According to the results of K and O-index, water from water supply plant showed higher K-index which means good for the health. Otherwise, spring water indicated higher O-index that people can feel more delicious than tap water. Futhermore, the mineral distribution of source water from water supply plants and spring water had indicated high correlation with geological effect.

• Journal of Korea Water Resources Association
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• v.51 no.spc
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• pp.1067-1078
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• 2018

Water resources projection typically consists of several stages including emission scenarios, global circulation models (GCMs), downscaling techniques, and hydrological models, and each stage is a source of total uncertainty in water resources projection. Several studies proposed methods to quantify the relative contribution of each stage to total uncertainty, and we call such analysis uncertainty decomposition. Uncertainty decomposition enables us to investigate the stages yielding large uncertainties and to establish the uncertainty reduction plan that reflects them. Interactions between stages is one of the important issues to be considered in uncertainty decomposition. This study suggests a new uncertainty decomposition method considering interaction effect. The proposed method has an advantage of decomposing the total uncertainty to the uncertainty from each stage considering both the main and interactions effects. We apply the proposed method to streamflow projection for Chungju Dam basin. The results show that the uncertainties from the main effects are larger than the uncertainties from interaction effects in both summer and winter. Using the proposed uncertainty decomposition method, we show that the GCM stage is the largest source of the total uncertainty in summer and the downscaling technique stage is the one in winter among the following four stages: emission scenarios, GCMs, downscaling techniques, and hydrological models.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.124-132
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• 2019

BACKGROUND: Silver grass (Miscanthus sinensis) No. 1 was developed for production of bio-ethanol, and for the purpose the silver grass growing sector was established in Geumgang basin, Iksan, Jeonbuk, in 2011. However, the other application potentials except for using as the bio-energy resources should be considered because of the drop in international oil prices. Therefore, there is the necessity of a scientific basis to use the silver grass instead of rice straw as the organic matter source that is used for improvement of soil quality in the plastic film house. METHODS AND RESULTS: The silver grass was applied at 5, 10, 15 and 20 Mg/ha and tilled before the watermelon was planted in the plastic film-house. The control plot was treated with 10 Mg/ha with rice straw, and watermelons have been cultivated for 3 years(2017~2019). Soil aggregation, soil chemistry, and the growth characteristics were investigated, when the watermelon was harvested every year. Soil aggregation levels at the 2nd and 3rd year of watermelon harvest were similar from the plot applied with the silver grass at 5 Mg/ha and the control plot, and increased in the silver grass treated plots with more than 10 Mg/ha. However, there was no statistically significant difference between the plots. The nitrogen mineralization of silver grass in the control plot tended to be similar to the 5 Mg/ha plot, but the silver grass treated plots with over 10 Mg/ha showed low nitrogen mineralization. Soil EC on harvest stage was proportional to the applied mass of the silver grass, but pH was in inverse with the applied mass. Soil organic matter content, available phosphate, and exchangeable cations increased with the continued use of silver grass. Watermelon weight found to be the best on more than 15 Mg/ha of silver grass, and the sugar content was highest when 10 Mg/ha was treated. CONCLUSION: The use of the silver grass at 10 Mg/ha annually as the organic source was effective in replacing rice straw while growing fruits and vegetables on the plastic film house.

• Economic and Environmental Geology
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• v.38 no.6 s.175
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• pp.607-622
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• 2005

This study was carried out in order to evaluate where the soil loss was mainly occurred, .and to verify how riverbed sediments in the tributaries of the Seomjin River were related to their source rocks distributed in Sunchang area. The study area including the Seomjin River with 4 tributaries of Kyeongcheon, Okgwacheon, Changjeong-cheon and Ipcheon was divided into 10 watershed. The RUSLE (Revised Universal Soil Loss Equation) was estimated for all the grids (10 m cells) in the corresponding watershed. The amount of soil loss per unit area was calculated as follows: dry fold (53,140.94 tons/ha/year), orchard (25,063.38 tons/ha/year), paddy field (6,506.7 tons/ha/year) and Idlest (6,074.36 tons/ha/year). The differences of soil loss per unit area appear to be depends on areas described earlier. Soil erosion hazard zones were generally distributed within dry fields. Several thematic maps such as land use maps, topographical maps and soil maps were used as a data to generate the RUSLE factors. The amount of soil loss, computed by using the RUSLE, showed that soil loss mainly occurred at the regions where possible source rocks were distributed along the stream. Based on the this study on soil loss and soil erosion hazard zone together with chondrite-normalized REE patterns that were previously analyzed in same study area, a closed relationship between riverbed sediments and possible source rocks is formed. Especially in the Okgwacheon that are widely distributed by various rocks, chondrite-normalized REE pattern derived from the riverbed sediments, source rock and soil is expected to have a closed relationship with the distribution of soil loss.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.4
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• pp.209-221
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• 2006

The purpose of this study is to analyze the effects of climate change on the nonpoint source pollution in a small watershed using a mid-range model. The study area is a basin in a rural area that covers 384 ha with a composition of 50% forest and 19% paddy. The hydrologic and water quality data were monitored from 1996 to 2004, and the feasibility of the GWLF (Generalized Watershed Loading function) model was examined in the agricultural small watershed using the data obtained from the study area. As one of the studies on climate change, KEI (Korea Environment Institute) has presented the monthly variation ratio of rainfall in Korea based on the climate change scenario for rainfall and temperature. These values and observed daily rainfall data of forty-one years from 1964 to 2004 in Suwon were used to generate daily weather data using the stochastic weather generator model (WGEN). Stream runoff was calibrated by the data of $1996{\sim}1999$ and was verified in $2002{\sim}2004$. The results were determination coeff, ($R^2$) of $0.70{\sim}0.91$ and root mean square error (RMSE) of $2.11{\sim}5.71$. Water quality simulation for SS, TN and TP showed $R^2$ values of 0.58, 0.47 and 0.62, respectively, The results for the impact of climate change on nonpoint source pollution show that if the factors of watershed are maintained as in the present circumstances, pollutant TN loads and TP would be expected to increase remarkably for the rainy season in the next fifty years.

• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.200-211
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• 2009

A mathematical modeling program called Soil and Water Assessment Tool (SWAT) developed by USDA was applied to Kyongan stream watershed. It was run under BASINS (Better Assessment Science for Integrating point and Non-point Sources) program, and the model was calibrated and validated using KTMDL monitoring data of 2004${\sim}$2008. The model efficiency of flow ranged from very good to fair in comparison between simulated and observed data and it was good in the water quality parameters like flow range. The model reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The results of pollutant loads estimation as yearly (2004${\sim}$2008), pollutant loadings from 2006 were higher than rest of year caused by high precipitation and flow. Average non-point source (NPS) pollution rates were 30.4%, 45.3%, 28.1% for SS, TN and TP respectably. The NPS pollutant loading for SS, TN and TP during the monsoon rainy season (June to September) was about 61.8${\sim}$88.7% of total NPS pollutant loading, and flow volume was also in a similar range. SS concentration depended on precipitation and pollution loading patterns, but TN and TP concentration was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. SWAT based on BASINS was applied to the Kyongan stream watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and non-point sources in watershed scale.