• Journal of Environmental Science International
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• v.23 no.9
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• pp.1643-1654
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• 2014

The university is one of the main energy consumption facilities and thereby releases a large amount of greenhouse gas (GHG). Accordingly, efforts for reducing energy consumption and GHG have been established in many local as well as international universities. However, it has been limited to energy consumption and GHG, and has not included air pollution (AP). Therefore, we estimated GHG and AP integrated emissions from the energy consumed by Seoul National University of Science and Technology during the years between 2010 and 2012. In addition, the effect of alternative energy use scenario was analysed. We estimated GHG using IPCC guideline and Guidelines for Local Government Greenhouse Inventories, and AP using APEMEP/EEA Emission Inventory Guidebook 2013 and Air Pollutants Calculation Manual. The estimated annual average GHG emission was $11,420tonCO_{2eq}$, of which 27% was direct emissions from fuel combustion sectors, including stationary and mobile source, and the remaining 73% was indirect emissions from purchased electricity and purchased water supply. The estimated annual average AP emission was 7,757 kgAP, of which the total amount was from direct emissions only. The annual GHG emissions from city gas and purchased electricity usage per unit area ($m^2$) of the university buildings were estimated as $15.4kgCO_{2eq}/m^2$ and $42.4tonCO_{2eq}/m^2$ and those per person enrolled in the university were $210kgCO_{2eq}$/capita and $577kgCO_{2eq}$/capita. Alternative energy use scenarios revealed that the use of all alternative energy sources including solar energy, electric car and rain water reuse applicable to the university could reduce as much as 9.4% of the annual GHG and 34% of AP integrated emissions, saving approximately 400 million won per year, corresponding to 14% of the university energy budget.

• Journal of the Korean Institute of Gas
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• v.10 no.4 s.33
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• pp.34-40
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• 2006

This paper provides a fusion technology between a district cooling energy system and an environment conservation policy based on the energy savings and reusable cold energy resources. The district heating and cooling systems are very effective ways for an energy saving, a cost reduction and a safety control. It is necessary to equalize the energy savings and an environmental preservation policy for an improved human lift. A gasification process of a liquefied natural gas, cooling water from deep seawater and an ice water thermal storage system may produce a cold energy. A district cooling system is used to cool an apartment, office buildings and factory facilities with a cooling energy supply pipeline. LNG cooling energy will switch a conventional air-conditioning system, which is operated by on electrical energy and a Freon refrigerant. Coincident with significant clean energy and operating cost savings, LNG cold energy system owen radical reductions in an air-borne pollutant, $CO_2$ and the release of environmentally harmful refrigerants compared with that of the conventional air-conditioning system. This study provides useful information on the fusion technology of a LNG cold energy usage and energy savings, and environmental conservation.

• Fisheries and Aquatic Sciences
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• v.7 no.2
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• pp.76-83
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• 2004

To supply fresh and quality quarantined seafood in live seafood specialty restaurants, facilities for short-term culture or holding of live marine fish and shellfish are a necessity. In this study, the performance of a simple recirculating aquarium system for the culture and holding of marine fish was evaluated. The aquarium system consisted of a culture tank, a foam fractionator for solids removal, and a Styrofoam bead filter for nitrification and solids trapping. In the first trial, the aquarium was stocked with a total of 12 kg Korean rockfish, which were fed approximately $0.5\%$ of the total fish body weight daily. During the 2-month culture period, total ammonia nitrogen (TAN) and nitrite nitrogen $(NO_2-N)$ concentrations remained below 1mg/L and 2mg/L, respectively. The chemical oxygen demand (COD) fluctuated between 13.6 and 31.2 mg/L on selected sampling days. The total suspended solids (TSS) removed by the foam fractionator was between 2.7 and 4.6g daily. The Styrofoam bead filter not only reduced TAN and $NO_2-N$ in the culture tank water, but also trapped solids equivalent to 8.3-26.7\% of the weight of feed supplied. In Trial 2, 30kg of live fish were held in the aquarium without feeding for a 24-hour period and the water quality parameters were monitored. TAN and $NO_2-N$ concentrations first increased and then decreased to around 0.3mg/L. These results demonstrate that the recirculating aquarium system is a functional option for the short-term culture or holding of marine fish.

• Membrane Journal
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• v.4 no.4
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• pp.213-220
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• 1994

Reverse osmosis(R/O) pilot system, which consists of pretreatments and R/O membranes, was demonstrated to regenerate the petroleum refinery wastewater for the process feedwater supply. Despite of the unsteady quality of the wastewater effluent from the process facilities, relatively high salt rejection of 96~99% was obtained and the product water showed a feasible quality for the use of cooling tower feed water. The results of R/O membrane module cleaning with NaOH solution represented that there was some fouling effects on the membrane performance during the period of test due to the ineffective treatment processes proposed and used in this study.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.14-27
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• 2020

The drought has occurred from the past, and has caused a lot of damage. It is important to analyze the past droughts and predict them in the future. In this study, the temperature and precipitation of the past and the future from climate change RCP 4.5 and 8.5 scenarios were analyzed for Seosan and Boryeong in the western region of Chungnam Province, which is considered as a drought-prone area on the Korean Peninsula. Comparing Standardized Precipitation Index (SPI) and Effective Drought Index (EDI) based on the past droughts, EDI was verified to be more suitable for the drought assessment. According to RCP 4.5, the frequency and intensity of droughts in the early future (2021~2060) were expected to increase and to be stronger. Particularly, severe droughts were predicted for a long time from 2022 to 2026, and from 2032 to 2039. Droughts were expected to decrease in the late future (2061~2100). From RCP 8.5, drought occurrences were predicted to increase, but the intensity of the droughts were expected to decrease in the future. As a result of evaluation of the frequencies of droughts by seasons, the region would be most affected by fall drought in the early future and by spring drought in the late future according to RCP 4.5. In the case of RCP 8.5, the seasonal effects were not clearly distinguished. These results suggest that droughts in the future do not have any tendency, but continue to occurr as in the past. Therefore, the measures and efforts to secure water resources and reinforcement of water supply facilities should be prepared to cope with droughts.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.5
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• pp.459-465
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• 2022

This paper reports a method to use a wireless sensor network deployed in the field to real-time monitor soil moisture, warning when the moisture level reaches a specific value, and wirelessly controlling an additional device (LED or water supply system, etc.). In addition, we report all processes related to wireless irrigation system, including field deployment of sensors, real-time monitoring using a smartphone, data calibration, and control of additional devices deployed in the field by smartphone. A commercially available open-source Internet of Things (IoT) platform, NodeMCU, was used, which was combined with a 9V battery, LED and soil humidity sensor to be integrated into a portable prototype. The IoT-based soil humidity sensor prototype deployed in the field was installed next to a tree for on-site demonstration for the measurement of soil humidity in real-time for about 30 hours, and the measured data was successfully transmitted to a smartphone via Wifi. The measurement data were automatically transmitted via e-mail in the form of a text file, stored on the web, followed by analyses and calibrations. The user can check the humidity of the soil real-time through a personal smartphone. When the humidity of a soil reached a specific value, an additional device, an LED device, placed in the field was successfully controlled through the smartphone. This LED can be easily replaced by other electronic devices such as water supplies, which can also be controlled by smartphones. These results show that farmers can not only monitor the condition of the field real-time through a sensor monitoring system manufactured simply at a low cost but also control additional devices such as irrigation facilities from a distance, thereby reducing unnecessary energy consumption and helping improve agricultural productivity.

• Journal of The Geomorphological Association of Korea
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• v.18 no.1
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• pp.1-13
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• 2011

The catch canal for a natural drainage, the excavation of tunnel for a stable irrigation, the artifical channelization of yazoo stream, many kinds of the pumping and drainage systems are found around Daedong-myeon, Gimhae-si. It could be confirmed that the deveolpment, maintenance and management of those facilities in the floodplain are mainly controlled by the geomorphological conditions. In case of Unha-chon, especially, the water can always be supplied only by openning the gate of irrigation tunnel and the Woldang pumping station as the largest pumping station in this area can supply water to Unha-chon area directly from the main river, Nakdong-gang. Because the Gamnae-chon which was an upper reach of the Unha-chon and is now connected to the Nakdong-gang through the Deoksan catch canal, the damage of flood and the burden of drainage are mitigated at the lower area of the Unha-chon.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.510-523
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• 2020

This study analyzed groundwater quality in hydroponic cultivation facilities. Through this study, the possibility of groundwater use was evaluated according to the quality of the groundwater for hydroponic cultivation facilities. Good groundwater quality, on average, is pH 6.61, EC 0.27 dS/m, NO3-N 7.64 mg/L, NH4+-N 0.80 mg/L, PO4-P 0.09 mg/L, K+ 6.26 mg/L, Ca2+ 18.57 mg/L, Mg2+ 4.38 mg/L, Na+ 20.85 mg/L, etc. All of these satisfy the water quality standard for raw water in nutrient cultivation. But in the case of farmers experiencing problems with groundwater quality, most of the items exceeded the water quality standard. As a result of the analysis, it was judged that purifying groundwater of unsuitable quality for crop cultivation, and using it as raw water, was effective in terms of water quality and soil purification. If an agricultural water purification system is constructed based on the results of this study, it is judged that the design will be easy because the items to be treated can be estimated. If a purification system is established, it can use groundwater directly in the facility and for horticulture. These study results will be available for use in sustainable agriculture and environments.

• Journal of Wetlands Research
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• v.23 no.1
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• pp.14-26
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• 2021

Increase of climate variability due to climate change has paved the way for regional drought monitoring and outlook. In particular, Gimcheon-si, Gyeongsangbuk-do, is suffering from frequent and periodic drought damage as the frequency and magnitude of drought are increasing due to climate change. For this reason, it is necessary to analyze drought characteristics for sub-districts based on water district and calculate the basic low-flow considering climate change. In this study, meteorological and hydrological drought outlook were carried out for 8 sub-districts considering the water supply system and regional characteristics of Gimcheon-si according to various climate change scenarios. In addition, the low-flow frequency analysis for the near future was also performed using the total amount of runoff and the low-flow. The overall results indicated that, meteorological droughts were found to be dangerous in the S0(1974~2019) period and hydrological droughts would be dangerous in the S2(2041~2070) period for RCP 4.5 and in S3(2071~2099) period for RCP 8.5. The results of low-flow frequency analysis indicated that future runoff would increase but drought magnitude and frequency would increase further. The results and methodology may be useful for preparing local governments' drought measures and design standards for local water resources facilities.

• Journal of Appropriate Technology
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• v.5 no.1
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• pp.18-24
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• 2019

Citarum river in West Java, Indonesia plays strategic roles for Jakarta metropolitan areas. Besides it provides major source of water supply such as domestics and drinking water including Jakarta, it also provides water for hundreds of industries through its cascade reservoirs. However, recently, Citarum river basin has been seriously suffering from water and groundwater pollution as well as the lowering-down of groundwater level due to the extreme use of water resources in dry season by domestic and industrial activities. This project objectives are design and installation of industrial wastewater treatment/recycle facilities to overcome the problem of water pollution and the lowering-down of groundwater level in Bandung. For these, cyclone type dissolved air flotation (DAF), CYFLOAT, was successfully installed as the appropriate technology for the target textile industry with 100 ton/day of capacity. The CYFLOAT system can remove the 96.8% of particulates, which are known as a critical factor to recycle the wastewater, within 40 min of residence time. Furthermore, The CYFLOAT system can reduce the operational cost and land use. The project was carried out in strong partnership with local institute including UNPAR, IBT, and PUSKIM for the sustainability of the technology to textile industry complex in Indonesia.