• Journal of Korea Water Resources Association
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• v.40 no.6 s.179
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• pp.469-483
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• 2007

Nitrate and chloride are the most common contaminants in groundwater and their concentrations increase easily due to fertilizer consumption and urbanization. The number of time series data for groundwater quality at a single site was not sufficient to analyze trends on Jeju Island. Therefore rectangle grids were drawn for the whole island and single grid was determined to be $500m{\times}500m$ after considering similar stream density, homogeneous hydraulic coefficients, geologic features of volcanic rock and low topographic slopes. All data within each lattice were collected and arranged in time series order and analyzed using Sen's method. 10.6 % of the total lattices for chloride and 22.4% for nitrate showed upward trends from the early 1990's to the early 2000's. Especially, upward trends for nitrate concentration are distinct in the low mid-mountainous areas of western and southern watersheds. Many septic tanks and much domestic waste from the urbanization of the low mid-mountainous area have produced this upward trend. Additionally, the agricultural region has dramatically increased since the 1990's and this has led to an increase of fertilizer consumption and, as a result, nitrate concentration. Therefore, the target of any management plan for groundwater quality on Jeiu Island needs to be focused on careful land use decisions in the mid-mountainous areas which are near Halla Mountain.

• Economic and Environmental Geology
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• v.42 no.2
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• pp.133-141
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• 2009

For economic impact analysis on a R&D project of high-yield groundwater development in Jeju conducted by KIGAM from 2004 to 2007, benefit/cost ratio(BCR), net present value(NPV), and internal rate of return(IRR) were calculated by contingent valuation method(CVM), production function analysis, domestic water market analysis and technology factor analysis. Measurable direct impact parameters among the major outputs of this R&D project consisted the estimation 4 high-yield and high mineral groundwater reserve in Jeju. Annual use of the reserve by piped water and bottled water was estimated as 12.23 million ton and its monetary value was calculated as 293.4 million dollar in 2006 year value applied of 5.5% discount rate. Economic impact of this R&D project in NPV of year 2006, with applying a discount rate of 5.5%, was identified and estimated as 13.66 million dollar in NPV, 4.05 points in BCR, and 22.74% in IRR, respectively. Additional early launch benefit was 5.58 million dollar. Even increased of the 1% discount rate, NPV of this R&D project was also positive as 12.18 million dollar and BCR was 3.71.

• Korean Journal of Plant Resources
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• v.25 no.2
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• pp.200-208
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• 2012

The bulbil of the $Dioscorea$ $species$ is produced, the amount of which is 2,000 tons annually, but it has been discarded without specific use. In this study the antioxidant and antimutagenicity of bulbil of the $Dioscorea$, which compared to bulbil of Danma($Dioscorea$ $japonica$ Decaisne) and Jangma($Dioscorea$ $batatas$ Decaisne), a major domestic cultivation species. The study was done by extracting bulbil of the Dioscorea methanol and the methanol extracts was re-extracted with chloroform, ethyl acetate, $n$-butanol and water. In methanol extract of Danma and Jangma, polyphenolic compounds contained 2.2 and 3.9 mg/g extract, respectively. The ethyl acetate fraction of Danma and Jangma had higher polyphenolic contents of 33.9 and 39.1 mg/g, whereas water fractions were much lower at 2.4 and 5.8 mg/g. Determination of antioxidant activity showed that the ethylacetate fraction strong DPPH radical scavenging activity and ABTS radical scavenging activity. The inhibitory effects of methanol extracts and chloroform, ethylacetate, $n$-butanol, water fraction from bulbil of Danma and Jangma on the mutagenicity in 1-NP, $AFB_1$, Trp-P-1 were investigated using $S.$ $typhimurium$ TA98. Danma and Jangma cultivars decreased the reverse mutation induced by 1-NP, $AFB_1$, Trp-P-1 in $S.$ $typhimurium$ TA98. The fraction of chloroform and ethylacetate showed strong inhibitory effects, in a dose dependant manner against the mutagenicities induced by 1-NP, $AFB_1$, Trp-P-1 in $S.$ $typhimurium$ TA98.

• Korean Chemical Engineering Research
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• v.43 no.5
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• pp.549-559
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• 2005

Sustainable industrial development which can minimize an ecological effect by the mankind exertion is recently interested due to an environmental contamination and a resource exhaustion problem. An eco-industrial park (EIP) is a community of manufacturing and service businesses seeking enhanced environmental and economic performance through collaboration in managing environmental and resource issues, including energy, water, and materials. EIP developments which improve a production plant within an eco-friendly greenfield and design a new industrial ecosystem are accomplished recently, which can efficiently re-use the waste and resources from each company within EIP. In this review, the outside and domestic case studies of EIP and cornerstone technologies to develop the EIP, such as energy integration, waste reuse, mass flow analysis, water pinch, and life cycle assessment, are summarized.

• Korean Journal of Remote Sensing
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• v.38 no.5_1
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• pp.571-585
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• 2022

As the threat of natural disasters such as droughts, floods, forest fires, and landslides increases due to climate change, social demand for high-resolution soil moisture retrieval, such as Synthetic Aperture Radar (SAR), is also increasing. However, the domestic environment has a high proportion of mountainous topography, making it challenging to retrieve soil moisture from SAR data. This study evaluated the usability of Sentinel-1 SAR, which is applied with the Artificial Neural Network (ANN) technique, to retrieve soil moisture. It was confirmed that the backscattering coefficient obtained from Sentinel-1 significantly correlated with soil moisture behavior, and the possibility of stand-alone use to correct vegetation effects without using auxiliary data observed from other satellites or observatories. However, there was a large difference in the characteristics of each site and topographic group. In particular, when the model learned on the mountain and at flat land cross-applied, the soil moisture could not be properly simulated. In addition, when the number of learning points was increased to solve this problem, the soil moisture retrieval model was smoothed. As a result, the overall correlation coefficient of all sites improved, but errors at individual sites gradually increased. Therefore, systematic research must be conducted in order to widely apply high-resolution SAR soil moisture data. It is expected that it can be effectively used in various fields if the scope of learning sites and application targets are specifically limited.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.6
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• pp.51-64
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• 2022

Along with the urbanization, the risk of urban flooding due to climate change is increasing. Flood regulation, one of the ecosystem services, is implemented in the different level of function of flood risk mitigation by the type of ecosystem such as forests, arable land, wetlands etc. Land use changes due to development pressures have become an important factor in increasing the vulnerability by flash flood. This study has conducted evaluating the urban flood regulation service using InVEST UFRM(Urban Flood Risk Model). As a result of the simulation, the potential water retention by ecosystem type in the event of a flash flood according to RCP 4.5(10 year frequency) scenario was 1,569,611 tons in urbanized/dried areas, 907,706 tons in agricultural areas, 1,496,105 tons in forested areas, 831,705 tons in grasslands, 1,021,742 tons in wetlands, and 206,709 tons in bare areas, the water bodies was estimated to be 38,087 tons. In the case of more severe 100-year rainfall, 1,808,376 tons in urbanized/dried areas, 1,172,505 tons in agricultural areas, 2,076,019 tons in forests, 1,021,742 tons in grasslands, 47,603 tons in wetlands, 238,363 tons in bare lands, and 52,985 tons in water bodies. The potential economic damage from flood runoff(100 years frequency) is 122,512,524 thousand won in residential areas, 512,382,410 thousand won in commercial areas, 50,414,646 thousand won in industrial areas, 2,927,508 thousand won in Infrastructure(road), 8,907 thousand won in agriculture, Total of assuming a runoff of 50 mm(100 year frequency) was estimated at 688,245,997 thousand won. In a conclusion. these results provided an overview of ecosystem functions and services in terms of flood control, and indirectly demonstrated the possibility of using the model as a tool for policy decision-making. Nevertheless, in future research, related issues such as application of models according to various spatial scales, verification of difference in result values due to differences in spatial resolution, improvement of CN(Curved Number) suitable for the research site conditions based on actual data, and development of flood damage factors suitable for domestic condition for the calculation of economic loss.

• Resources Recycling
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• v.32 no.2
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• pp.12-18
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• 2023

In 2018, the demand for silver (referred to as Ag) in the electrical and electronics sector was 249 million tons. The demand stood at 81 million tons in the solar module production sector. Currently, due to the rapid increase in solar module installation, the demand for silver is increasing drastically in Korea. However, Korea's natural metal resources and reserves are insufficient in comparison to their consumption, and the domestic silver ore self-sufficiency rate was as low as 2.2% as of 2021. This implies that a recycling technology is necessary to recover valuable metal resources contained in the waste plating solution generated in the metal industry. Therefore, this study compared and analyzed, the results of the impact evaluation through life cycle assessment according to an improvement in the process of recovery of valuable metals in the waste plating solution. The process improvement resulted in reducing GWP (Global Warming Potential) and ADP(Abiotic Depletion Potential) by 50% and 67%, respectively. The GWP of electricity and industrial water was reduced by 98% and 93%, respectively, which significantly contributed to the minimization of energy and water consumption. Thus, the improvement in recycling technology has a high potential to reduce chemical and energy use and improve resource productivity in the urban mining industry.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.67-72
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• 2017

This study developed an electric power propulsion personal watercraft by combining a battery and an electric system from the domestic automobile industry with water motorcycle from marine leisure industry in a convergence of technology. It also developed a safety inspection plan and type approval standard for personal watercraft that use electric power propulsion. For the registration and production of the electric power PWC (Personal Watercraft), a safety inspection standard (draft) and type approval standard (draft) have been established. PWC that use this electric power propulsion certification standard have been divided into two categories according to the use of gasoline engines as related to the ship's electrical system. The contents of these safety inspections standards is divided into 7 categories, and their purpose is to confirm the facilities used for the safe operation of PWC. Type approval is divided into 7 categories and is intended to ensure the safe production of PWC. This is basic data can be used to establish criteria for safety inspection and type approval of electric power propulsion vessels and to guide the production of the environmentally friendly PWC in Korea.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.4
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• pp.517-527
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• 2023

Objectives: We examine cases of chemical poisoning that occurred in the cleaning of metal parts and the regulations on halogenated solvents in other countries and propose regulations necessary to prevent chemical poisoning from halogenated solvents. Methods: We collected cases of chemical poisoning through the website of the Korea Occupational Safety and Health Agency. A review of the literature was conducted focusing on regulations related to halogenated solvents in the United States and the European Union, particularly for cleaning metal parts. Among the Material Safety Data Sheets submitted to the government, MSDS containing eleven substances were extracted to confirm the composition and product use. We investigated cleaning methods for metal parts used in South Korea. For the hazard classification, the European Chemicals Agency or Japan's NITE's website was used. Results: In the case of poisoning, the cleaning methods involving trichloromethane were dipping and dry, which was not found in the literature. It was confirmed that many halogenated solvents and dimethyl carbonate were used for metal cleaning in South Korea. In vapor degreasing using TCE in the USA, even if the facility is strictly managed, such as by installing cooling coils in open cleaning facilities, the risk of exposure to TCE is considered to be not only carcinogenic but also a concern for acute and chronic effects. In comparison, exposure through Korean work methods such as dipping and drying operations is inevitably much higher. Conclusions: The transition to water-based cleaning with low-hazard chemicals should be a priority in the cleaning process. In the case of metal parts that require precise cleaning, if the use of a halogenated solvent is inevitable, a closed degreasing facility should be used to minimize exposure. The current regulations in the Occupational Safety and Health Act, the Chemical Substances Control Act, and the Air Environment Conservation Act do not require cleaning facilities to minimize emissions. To protect the health of workers using halogenated solvents to clean metal parts, regulations that require a fundamental reduction in exposure will be necessary.

• Journal of the Korea Organic Resources Recycling Association
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• v.20 no.4
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• pp.97-105
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• 2012

This study examined for possibility of the food wastewater incineration treatment method as one of overland treatment method by incineration through liquefied spray of food wastewater when incinerating domestic wastes under operation and for the relationship, etc of air discharge material discharged in incineration, and the results of study are as follow: The food wastewater as one of overland treatment method was analysed 94-96% of moisture contents. Temperature of incinerator outduct during mixed incineration of food wastewater with MSW was average $897^{\circ}C$ and incineration of only MSW was $925^{\circ}C$. Temperature of the mixed incineration of food wastewater was dropped about $28^{\circ}C$ by incineration of only MSW. Concentration of nitrogen oxides(NOx) among air discharge gases was studied by 50ppm, 46ppm when inputting $200{\ell}/hr$, $300{\ell}/hr$ into the incinerator as the quantity of food wastewater. In the mixed incineration of food wastewater, generation speed of scales in the inside of a tubular exhaust gas boiler became rapid and the scale generation quantity became large but the exhaust gas boiler normally operated since scales were removed in cleaning of the tube with a compressive air cleaning facility and there was no opening clogging phenomena in a filter cloth of the filtering dust collector. The overland treatment method, not ocean dumping of food wastewater can be proposed as a technology since mixed incineration of food wastewater with MSW in the existing domestic waste incineration plant is possible, and operation costs of the incineration facility were reduced since use of chemicals such as ammonia and urinary hydrogen ion excretion, etc used in incineration facilities for removing nitrogen oxides(NOx).