• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.5
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• pp.96-105
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• 2002

As an useful water purification system for non-point source pollution in rural watersheds, interests in constructed wetlands are growing at home and abroad. It is well known that constructed wetlands are easily installed, no special managemental needs, and more flexible at fluctuating influent loads. They have a capacity for purification against nutrient materials such as phosphorus and nitrogen causing eutrophication of lentic water bodies. The Constructed Wetland Design Model (CWDM), developed through this study is consisted mainly of Database System, Runoff-discharge Prediction Submodel, Water Quality Prediction Submodel, and Area Assessment Submodel. The Database System includes data of watershed, discharge, water quality, pollution source, and design factors for the constructed wetland. It supplies data when predicting water quality and calculating the required areas of constructed wetlands. For the assessment of design flow, the GWLF (Generalized Watershed Loading Function) is used, and for water quality prediction in streams estimating influent pollutant load, Water Quality Prediction Submodel, that is a submodel of DSS-WQMRA model developed by previous works is amended. The calculation of the required areas of constructed wetlands is achieved using effluent target concentrations and area calculation equations that developed from the monitoring results in the United States. The CWDM is applied to Bokha watershed to appraise its application by assessing design flow and predicting water quality. Its application is performed through two calculations: one is to achieve each target effluent concentrations of BOD, SS, T-N and T-P, the other is to achieve overall target effluent concentrations. To prove the validity of the model, a comparison of unit removal rates between the calculated one from this study and the monitoring result from existing wetlands in Korea, Japan and United States was made. As a result, the CWDM could be very useful design tool for the constructed wetland in rural watersheds and for the non-point source pollution management.

• Journal of environmental and Sanitary engineering
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• v.8 no.2
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• pp.25-48
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• 1993

International concern over the environmental pollution is ever increasing, and diversified countermeasures must be devised in Korea also. Global trend, damages, problems and countermeasures with respect to issues mentioned in the Rio Declaration, such as prevention of ozone layer destruction, reduction of migratory atmospheric pollution between neighboring countries, and prevention of global greenhouse effect, were discussed in this report. Conclusion of the report is summarized as follows : A. Measurement, Planning and Monitoring (1) Development and implementation of a global network for measurement and monitoring from the global aspects such factors as related to acid rain(Pioneer substances, pH, sulfate, nitrate), effect of global temperature(Air temperature, $CO_2$, $CH_4$, CFC, $N_2O$) and destruction of ozone layer($CFC_S$). (2) Establishment of network system via satellite monitoring movement of regional air mass, damage on the ozone layer and ground temperature distribution. B. Elucidation of Present State (1) Improvement and development of devices for carbon circulation capable of accurately forecasting input and output of carbon. (2) Developmental research on chemical reactions of greenhouse gas in the air. (3) Improvement and development of global circulation model(GCM) C. Impact Assessment Impact assessment on ecosystem, human body, agriculture, floodgate, land use, coastal ecology, industries, etc. D. Preventive Measures and Technology Development (1) Development and consumption of new energy (2) Development of new technology for removal of pioneer substances (3) Development of substitute matter for $CFC_S$ (4) Improvement of agriculture and forestry means to prevent the destruction of ozone layer and the greenhouse effect of the globe (5) Improvement of housing to prevent the destruction of ozone layer and the greenhouse effect of the globe (6) Development of new technology for probing underground water (7) Preservation of forest (8) Biomass 5. Policy Development (1) Development of strategy model (2) Development of long term forecast model (3) Development of penalty charge effect and expense evaluation methods (4) Feasibility study on regulations By establishing the above mentioned measures for environmentally sound and sustainable development to establish the right to live for humankind and to preserve the one and only earth.

• Journal of environmental and Sanitary engineering
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• v.24 no.4
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• pp.112-115
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• 2009

This research was performed to purify water quality through removing T-N, and T-P and to estimating rate of $NO_x$ by the response of photocatalyst using ceramics. The ceramics was a mixtures of Titanium Diboride($TiB_2$) which is used to develop armored cars with excellent protective power and lightness, Olivine, and Hwangto with water and was furnaced for an hour at $1160^{\circ}C$. Hwangto and Olivine used in the study are produced at Haenam-gun, Jeonnam, and Andong-city, Gyeongsangbuk-do, respectively. The ground Hwangto and Olivine were seived through PR $100{\times}200$, and $TiB_2$ was a product of SIGMA ALDRICH. The experiment was performed under the sunlight, Mass flow controller was used for constant flow to pass through the pyrex reactor which was fully charged with furnaced ceramics. The concentration of $NO_2$ gas passed through the pyrex reactor was measured by Multi Gas Monitor. The reaction took for 60 minutes, The material was exposed to sunlight for 40 minutes. The sunlight was interrupted before and after the exposure for 10 minutes. The result showed that the concentration of $NO_2$ gas of the ceramics with $TiB_2$ and without $TiB_2$ became reduced and then maintained the same concentration under the sunlight, and became increased when the sunlight is interrupted. The $NO_2$ removing efficiency of the ceramics mixed with $TiB_2$ was 14~43% higher than that of the ceramics without $TiB_2$ under the sunlight. The study showed that the removing rate of $NO_2$ was 80% when the mixture rate of Hwangto, Olivine, and $TiB_2$ was 68%, 30% and 2%.

• Journal of Environmental Health Sciences
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• v.10 no.1
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• pp.13-20
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• 1984

The hospital wastewaters have to be so disposed as to prevent disease and to protect water resources from hazardous substances disinfectants, medicines, and chemicals. Polyvinylpyrrolidone-iodine complex (povidone-iodine) is widely used in the hospital as one of disinfectants. This study was carried out to manifest the effect of disinfectants in growth of activated sludge in treatment of the hospital wastewater by the activated sludge process. The results are as follow. 1. An average water quality of the hospital wastewater showed 7.2 in pH, 3.2 ppm in DO, 293.3 ppm in SS, 96.0 ppm in BOD, 151.1 ppm in COD, 0.4 ppm in povidone-iodine, 0.5 ppm in phenols, 5.4 ppm in surfactants, 1.6 ppm in o-phosphate, 4.6 ppm in $NH_3-N, 249\times 10^4$ counts/100 ml in coliform group organisms, and $1,369\times 10^2$ counts/ml in general counts of bacteria. And wastewater amounts discharged per bed was calculated 70 l/d/bed. 2. In batch culture activated sludge process, each of cresol and povidone-iodine was not effected in less than 0.1 ppm concentration, but the more concentration, the more inhibit the growth rate of activated sludge. In the mixture of two disinfectants, the growth was more inhibited the effect of single disinfectants. So that this reaction is considered as addition effect of two disinfectants. 3. The removal rates of the disinfectants-by continuous culture activated sludge process were 77.6% in 0.4 ppm povidone-iodine, and in BOD was 85.6%. 4. It is desirable that the hospital wastewater is planed in order to be discharged to two system separately, sewer from life system and wastewater from medical system. From those results, it has been concluded that the hospital wastewater has to be treated safely by the activated sludge process.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04b
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• pp.254-258
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• 1999

The distribution of anionic groups in the fibers, the fines, the colloidal fraction and the dissolved fraction, respectively, of thermomechanical pulp (TMP) suspensions was determined and peroxide bleaching of spruce TMP were also studied. Spruce TMP was extracted with hexane, treated with alkali, or bleached with peroxide. Suspensions made at pH 5.5 were fractionated into long fibres, large fines, small fines, a colloidal fraction and a dissolved fraction. The charge of the fractions was determined using polyelectrolyte titration. To determined the origin of the charges, the contents of fatty acids, resin acids and acidic units in hemicelluloses in the different fractions were determined by has chromatography. Extraction of TMP with hexane prior to fractionation increased the measured charge of the fibres. The removal of the wood resin probably uncovered some carboxyl groups on the fibre surfaces, or improved th e penetration of polybrene into the pores of the fibres. The charge of the fines and the colloidal fraction was lower when the wood resin had been removed. Alkaline treatment of the TMP increased the charge of the fibres and fines, mainly because of demethylation of pectins. Alkaline treatment increased the charge also of the dissolved fraction, because of the release the charge also of the dissolved fraction, because of the release of pectic acids into the water phase. Alkaline peroxide bleaching further increased the charge of fibres and the dissolved fraction, most likely because of lignin oxidation. The charge of the colloidal fraction, consisting mainly of wood resin, was only slightly affected by alkaline treatment and peroxide bleaching. The anionic groups in TMP suspensions were mainly free uronic acids in the hemicelluloses. The contribution from the fatty and resin acids was substantial only for the colloidal fraction.

• Journal of Korean Society on Water Environment
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• v.23 no.6
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• pp.951-960
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• 2007

Window interface to Hydrological Simulation Program-FORTRAN (WinHSPF) developed by the United States Environmental Protection Agency (EPA) was applied to the upstream of Nam-Han river watershed to examine its applicability for loading estimates in watershed scale and to evaluate non-point source control scenarios using BMPRAC in WinHSPF. The WinHSPF model was calibrated and verified for water flow using Ministry of Construction and Transportation (MOCT, 3 stations, 2003~2005) and water qualities using Ministry of Environment (MOE, 5 station, 2000~2006). Water flow and water quality simulation results were also satisfactory over the total simulation period. But outliers were occurred in the time series data of TN and TP at some regions and periods. Therefore, it required more profit calibration process for more various parameters. As a result, all the study was performed within the expectation considering the complexity of the watershed, pollutant sources and land uses intermixed in the watershed. The estimated pollutant load for annual average about $BOD_5$, T-N and T-P respectively. Nonpoint source loading had a great portion of total pollutant loading, about 86.5~95.2%. In WinHSPF, BMPRAC was applied to evaluate non-point source control scenarios (constructed wetland, wet detention ponds and infiltration basins). All the scenarios showed efficiency of non-point source removal. Overall, the HSPF model is adequate for simulating watersheds characteristics, and its application is recommended for watershed management and evaluation of best management practices.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.193-201
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• 1999

This study was conducted to check the applicability of pilot-scale co-composting for the remediation of diesel contaminated soil during the winter. Nutrients and microbes were added to enhance the efficiency of bioremediation and fermenting composts were also added to stimulate the microbial activities. As a result. the soil pile was kept at adequate temperature for the bioremediation during the test period of 30∼40 days and initial concentration(2,340mg TPH/kg dry soil) was reduced to 216mg TPH/kg dry soil (approximately 91% removal). During the initial 10∼30 days, it was found that the TPH concentration and the microbial population were rapidly reduced and increased. respectively. The co-composting technology studied can be effectively applied to remediate the diesel contaminated soil during the winter.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.11b
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• pp.159-163
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• 1999

Model experiments were conducted to investigate the effect of different fillers on the removal of toner ink. Combinations of different papers (commercial photocopy paper and filler-free paper), fillers (calcium carbonate, kaolin clay, and talc), and chemicals(1-octadecanol, stearic acid, oleic acid, and TOFA) and stearic acid were found to be effective in detachment and agglomeration of toner ink. Furthermore, pH had little effect on toner detachment and agglomeration, indicating both protonated fatty acids and their anions are equally effective. In the presence of either kaolin clay or talc, all these agglomerating agents are equally effective, although a slightly higher dosage(1% for clay and 2% for talc as compared with control) is required, presumably due to the adsorption of chemical by the filler. Calcium carbonate filler, on the other hand, has a significant and adverse effect on the fatty acids used but has little effect on 1-octadecanol with the exception of possible adsorption. While stearic acid is not effective, a much higher level of oleic acid or TOFA is needed when calcium carbonate fillers are present as compared to the filler-free case. Fatty acids react with calcium carbonate to form calcium salts. The availability of fatty acid anion for toner detachment and agglomeration is determined by the solubility of calcium salt of a given fatty acid. Calcium oleate is 10 times more soluble in water than calcium stearate.

• Korean Journal of Environmental Agriculture
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• v.31 no.4
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• pp.378-380
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• 2012

BACKGROUND: In Korea, green manure has been cultivated for reducing chemical fertilizer application, maintaining soil fertility, and feeding livestock in winter season. We evaluated the phosphate balance under green manure-rice cultivating system with different removal rates of green manure for maintaining soil fertility. METHODS AND RESULTS: The barley and hairy vetch mixture was selected as the green manure in this study. The barley and hairy vetch was sowed at a rate of 135 and 23 kg/ha, respectively, without fertilizer application. Total aboveground biomass was 12000 (barley: 5400 kg/ha, hairy vetch: 6600 kg/ha) kg/ha, and these green manure were incorporated with different input rates before rice planting. The input rates of green manure in this study were 0 (NPK+0%), 25 (NPK+25%), 50 (NPK+50%), 75 (NPK+75%) and 100 % (NPK+100) and the standard fertilization (NPK) without green manure cultivation. All treatments were applied with standard fertilizer (N-P-K: 90-19.6-48.3 kg/ha) before rice planting. The highest rice yield was observed in NPK+50% which was 20% higher compared with NPK. The phosphate balance with different incorporation rates of green manure was-104.0,-76.8,-52.9,-27.4, and 6.0 kg/ha for NPK+0%, NPK+25%, NPK+50%, NPK+75%, and NPK+100%, respectively. CONCLUSION(S): The use of green manure for livestock feeding in green manure-rice cropping systems could remove a huge amount of phosphate. This cropping system strongly requires phosphate application before green manure seeding for maintaining soil fertility.

• Applied Chemistry for Engineering
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• v.17 no.1
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• pp.58-61
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• 2006

The object of this study was to develop an advanced method for fluid flow and oxygen transmission and increase adhesive property of microorganism to waste plastic vessel that was made of microorganism media. Through lab scale experiments, we found the optimum packed media volume rate and method, and when the optimum condition was applied to pilot plant, we confirmed possibility of advanced treatment. The sewage that was used in the test was the sewage disposal facility established in C and K elementary schools, which utilized waste plastic media oxidation engineering method. Analysis showed that removal efficiency of organic matter, SS, T-N and T-P was very high, that the sewage disposal facility maintained stability of treatment when changeable load of raw sewage flowed in.