• Journal of Korean Society of Water and Wastewater
• /
• v.35 no.6
• /
• pp.497-505
• /
• 2021

This paper investigates the current status of Jeju special self-governing province (JSSGP)'s water infrastructure and recommends directions for improvement. JSSGP relies on groundwater for most of its water resources. Recently, water usage has been steadily increasing due to the increase of residents and tourists while the quality of groundwater has been steadily worsening. Deterioration in water quality of groundwater can be seen through the increase in concentration of nitrate nitrogen and microorganisms. To overcome such problems, water consumption must be reduced by water demand management in all fields including residential and agricultural water use. The quality of water resources should be preserved through the management of pollutants. For efficient management of water resources, great efforts should be made to reduce the leakage rates in household and agricultural water, which is currently at the highest level in the country. Furthermore, diversification of water intake sources other than groundwater is needed, especially for agricultural water supply. For water and sewerage facilities, compliance with drinking water quality standards and discharge water quality standards must be achieved through the optimization of operation management. This process requires recruiting professionals, improving existing workers' expertise, and improving facilities.

• Journal of Korea Water Resources Association
• /
• v.32 no.5
• /
• pp.537-545
• /
• 1999

This study examines three counterplans for the improvement in price structure of Korean multi-regional water supply system. First, price differentiation between industrial and residential water uses is analyzed using several pricing methods. It has been estimated that the industrial water price by the Ramsey pricing method is needed to be two to two and half times higher than the price of residential water to achieve maximum social welfare. Second, peak-load pricing is then studied to seek for the effectiveness of seasonal differentiation in water price. It has been found that consideration of dam facilities and their functions is the key factor for the effectiveness of the seasonal differentiation in water price. Finally, the discussion about the introduction of contract pricing system to the multi regional water supply system to achieve optimal investment plan for the future water demand is presented. We has found that the introduction of contract pricing system will greatly increase the efficiency in future investment plan of the multi-regional water supply system.

• Korean Journal of Ecology and Environment
• /
• v.40 no.1
• /
• pp.31-39
• /
• 2007

Monitoring data of 48 agricultural irrigation reservoirs from 1999 to 2004 was analyzed for water quality characteristics including biochemical oxygen demand $(BOD_5)$, chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and chl-${\alpha}$. Land uses of the watersheds associated with these reservoirs were determined for residential, forest, upland, paddy and miscellaneous, and regressed against water quality characteristics. Correlation analysis showed that forest land use was negatively correlated with all the water quality characteristics implying it's beneficial effects in water quality perspectives. Other land uses including residential, upland, and paddy generally illustrated positive correlation with water quality characteristics, which indicates most human activities of the watershed could degrade water quality of the receiving water bodies. Paddy land use partially contributed to the water quality degradation in contrast to the previous studies. It might be attributed to the relatively clean water quality of the study area, where even slight pollutant loading could degrade sensitively water quality. Further investigation is recommended for the effect of proximity as well as land use portions on the water quality of receiving water body.

• Journal of Environmental Impact Assessment
• /
• v.12 no.2
• /
• pp.73-86
• /
• 2003

In this study, we performed 8 times of water quality sampling and continuous measurement of flow to identify wastewater flow characteristics for wastewater treatment basins of Namyangju city. The field survey has been conducted 6 times in dry weather period and 2 times in wet weather period. Each survey conducted 24-hr water quality sampling in the interval of 2-hr. From the analysis of flow data and water quality data, the following conclusions can be drawn. For Namyangju-1 station, which represents residential and commercial mixed area, flow rises early in the morning before office-going hour and moves up and down within narrow range, and lasted after office-leaving hour, resulting from continuous commercial activity. In case of Namyangju-5 station representing community and Namyangju- 6 station representing residential area, the flow immediately falls down after rising early in the morning and later rises again at the office-leaving hour, and arrives at peak flows around late evening. In the analysis of wastewater characteristics for weekdays and weekends, without landuse types the flow rate of weekends is higher than that of weekdays because it reflects population, being not contributed to generate wastewater during the working hours of weekdays, stay home and produce wastewater for weekends period.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.757-760
• /
• 2008

Recently, improvements in the standard of living in industrial area require establishment of a convenient residential environment in order to enhance the quality of living, To achieve such an environment, it is necessary to effectively reduce or prevent various environmental problems occurring in and around residential areas. In this study, We focused on the water-purification properties of concrete using effective micro-organisms. Such as SS, BOD, COD, T-P, T-N. The ability of the removal of SS, T-P, T-N in the test water is superior to concrete using effective micro-organisms. As a result, concrete using effective micro-organisms has sufficient performance of water-purification.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2002.05a
• /
• pp.267-272
• /
• 2002

The electric heat pump requiring HCFCs as a refrigerant has been for most residential air-conditioners in Korea. They cause a surge up electric power demand during summer. Moreover, the use of HCFCs and HFCs causes a serious problem to the global environment such as global warming and ozone layer destruction. An absorption chiller and heater could solve such problems. It was built and tested for analyzing the performance of the absorption chiller/heater. Experiment was done with a 1.5RT household absorption chiller and heater. It was experimented that the cooling capacity, gas capacity, COP were researched by the temperature of cooling water. The change of the cooling water temperature have effect the temperature(or pressure) of the parts on absorption chiller The result of the change of the cooling water temperature have the effects of the absorption chillers. This data will help to operate the household absorption chiller and heater.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.14 no.4
• /
• pp.13-19
• /
• 2018

The Effects of hot water supply temperature on indoor thermal characteristics for floor radiant heating system in residential apartment were researched by computer simulation. The parametric study on hot water supply temperatures with different outdoor air temperatures was done with regard to energy performance and control characteristics, respectively. As a result, the maximum overshoot of indoor air temperature and energy consumption were reduced by adjusting the hot water supply temperatures with outdoor air temperatures.

• Journal of Ecology and Environment
• /
• v.32 no.2
• /
• pp.83-86
• /
• 2009

We conducted a landscape analysis to investigate the possibility of adverse effects of anthropogenic light sources, such as roads and residential buildings, on Lethocerus deyrollei on Jeju Island, Wetlands inhabited by L. deyrollei had fewer anthropogenic structures within a 3 km radius that had the potential to produce artificial light at night than wetlands not inhabited by L. deyrollei, In particular, the presence of artificial lights within a 1 km radius appears to reduce the probability of inhabitation by L. deyrollei, Our results suggest that artificial light sources may be critical determinants of L. deyrollei inhabitation patterns in a landscape, and that habitats that have a buffer area of at least 600$\sim$700 m radius free from residential buildings are the most appropriate habitats for L. deyrollei.

• 한국신재생에너지학회:학술대회논문집
• /
• 2008.05a
• /
• pp.29-32
• /
• 2008

Testing was conducted to determine the performance of a residential fuel cell system when subjected to DSS and WSS operation, especially for start-up and shut-down characteristics. In terms of start-up time, it took about 70min to start output power generation and stably to reach 1kW at cold start. Measurement of the characteristics of heat and power generation were carried out at start-up and shut-down time. Fuel gas is used for heating both reformer and stack from start-up to the beginning of power generation. In terms of start-up and shut-down characteristics, it was important to control the reformer temperature precisely. The average output water temperature during the rated output operation(960W) was $63.2^{\circ}C$ constantly. The results of the investigation are being used to develop a new test protocols for residential fuel cell system.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.11a
• /
• pp.19-22
• /
• 2007

In this study, we investigated operating characteristics of natural gas fuel processor for polymer electrolyte membrane fuel cells (PEMFCs). The fuel processor consists of a natural gas reformer, a water-gas shift reactor, a heat-exchanger and a burner, in which the overall integrated volume is exactly(exceptionally) small, namely, about 10L except outer insulation. The producted hydrogen is $1Nm^3/hr$ and the maximum thermal efficiency is ${\sim}76%$(low heating value) at full operating load. A compact and highly efficient $1Nm^3/hr$ class natural gas fuel processor was developed at UNISON is an advantage for application in residential PEMFCs co-generation systems.