• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.2
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• pp.29-34
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• 2009

A series of laboratory model tests and numerical analysis is performed to analyze characteristics of desalination and to predict a period of desalination for subsurface saturated soil in Saemanguem reclaimed area. The results show that quantity of desalination is small as salinity of water is increased. On the contrary, quantity of desalination is increased as salinity of soil is high. In order to decrease the salinity to 10 % of initial salinity of soil at depth of 2 m, it takes 11 years to desalinate the soil 50 m away from drainage ditch. For soil at depth of 1.5 m only 1 year to desalinate the soil near drainage ditch. Also, water head of 80 cm is required to desalinate to 10 % of initial salinity for 60 cm thick soil. Because the following results is based upon the Saemangeum soil, an application of this result for another field will be cautious. More research will be required on this matter.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.7-12
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• 2004

Desalination system of revers osmosis(RO) membrane has been proven to be the most economical not only for the desalination of water containing salts, but also for the concentration of solute. RO membranes were traditionally made of inorganic polymers such. as cellulose acetate(CA), Polyamide(PA). To retain more minerals in deep ocean water, a new hybrid membrane composed of tourmaline film as organic material onto inorganic layer of CA polymer in asymmetric structure was developed for RO membrane process. The performance tests were carried out in the permeability of pure water and the rejection of NaCl solution to evaluate the adaptability for DOW desalination. The results of these basic tests show possibility to apply the new hybrid RO membrane for the desalination with function control.

• Membrane Journal
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• v.26 no.5
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• pp.351-364
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• 2016

In recent decades, many researchers have tried to improve desalination performances of polyamide (PA) thin-film composite membranes (TFCs) by incorporating nanomaterials into a selective PA layer. This review focuses on PA-based nanocomposite membranes with high performances for energy-effective desalination in reverse osmosis. Carbon based nanomaterial (e.g., graphene oxide (GO), carbon nanotubes (CNT)) and/or other nanoparticles (e.g., zeolite, silica and etc.,) were applied to overcome the trade-off correlation between water permeability and salt rejection of current polymeric desalination membranes. Here, this brief review will discuss current studies of PA-based nanocomposite membranes with enhanced separation characteristics and provide the future research direction to achieve further improved desalination performances.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.18 no.1
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• pp.12-19
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• 2022

Desalination has the advantage of being easy to supply water resources. However most desalination devices are developed mainly for large plants and it is not common to use desalination system for a small fishing ship. More than 50% of the input fuel energy of the small shipbuilding's engine is wasted without reused in a ship, and it is necessary to improving the fuel efficiency of the small fishing ship. In this study, a desalination device using waste heat from engine of the ships was developed. As results, it was found that if the condensing chamber uses a fan to circulate the water vapor, the freshwater production was up to 40.0% higher, and the freshwater production efficiency was up to 30.1% increased when the fan was operated.

• Journal of Korea Water Resources Association
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• v.44 no.10
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• pp.809-817
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• 2011

We analyzed various cost components for approximately 40 small-scale island desalination plants operated by K-water. A significant factor affecting desalination cost was found, and we proposed a way to reduce desalination costs. All plants considered were reverse osmosis (RO) facilities. TDS concentrations of feed water varied from less than 1,000 mg/L (practically considered freshwater) to over 30,000 mg/L (nearly seawater). Analysis of desalination costs from 2005 to 2009 indicated that maintenance, labor, and energy were the three biggest components that accounted for 50.6%, 36.9% and 7.8%, respectively. It was well known that TDS of feed water directly affected energy needed for RO process. In this study we found that maintenance cost was also directly related to feed water TDS. This finding indicated that lowering feed water TDS might result in significant desalination cost reduction.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.197.1-197.1
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• 2010

This study was carried out to evaluate the operating performances of the evaporation desalination system with solar energy. This system was designed to use evacuated solar collector as the heat source, supplying the required heat energy and photovoltaic power as the electric source, supplying required power to pumps in the desalination system. The 5kW photovoltaic power generation system to make the electricity, the single-stage fresh water generator with plate heat exchanger, and remote control and monitoring system. Solar desalination system was designed and installed in Jeju-island, Korea in 2006, after about 4 years of operation, usability and stability of solar desalination system was guaranteed. The system comprises of the desalination unit which was designed to have daily fresh water capacity of $2m^3$, a $120m^2$ evacuated tubular solar collector to supply the heat, a $6m^3$ heat storage tank, and a 5.2kW photovoltaic power generation to supply the electricity to hydraulic pumps for the heat medium fluids. On a clear day, average daily solar irradiance in Jeju-island was measured to be $500W/m^2$ and the daily fresh water yield showed to be more than 500 liters under this condition. After around three years of a long term operation of the system from January 2007 to August 2009, average daily freshwater yield was analyzed to be around $330{\ell}$. The relationship equation between solar irradiance and freshwater yield was found to be y=1.1806x - 107.89.

• Journal of Korean Society on Water Environment
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• v.33 no.4
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• pp.403-408
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• 2017

In these days, wastewater reclamation and seawater desalination play essential role in addressing the challenge of worldwide water scarcity. Particularly, reverse osmosis (RO) for seawater desalination process is commonly used due to less energy consumption than conventional thermodynamic systems. However, membrane fouling and electrical energy consumption during operation of RO system for seawater desalination haver continued to be a obstruction to its application. In this study, therefore, wastewater secondary effluent is used for osmotic dilution of seawater. Firstly, fouling behaviour of RO by simulating wastewater effluent in osmotic dilution process was measured and we calculated energy consumption of overall desalination process by theoretical equations and commercial program. Our results reveal that RO membrane fouling can be efficiently controlled by pre-treatment systems such as nano filtration (NF) or forward osmosis (FO) process. Especially FO system for osmotic dilution process is a non-pressurized membrane system and, therefore, the operating energy consumption of overall desalination system was the lowest. Moreover, fouling layer on FO membrane is comparatively weak and reversible enough to be disrupted by physical cleaning. Thus, RO system with low salinity feed water through FO process is possible as a less energy consuming desalination system with efficient membrane fouling control.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.5
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• pp.255-268
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• 2016

Climate change has increased the need to secure a new water resource in addition to the traditional water resources such as surface water and ground water. The seawater desalination market is growing sharply in accordance with this situation in Korea, "seawater engineering & architecture of high efficiency reverse osmosis (SEAHERO)" program was launched in 2007 to keep pace with world market trend. SEAHERO program was completed in 2014, contributed to turn the domestic technology in evaporative desalination technology to RO desalination technology. Currently, it is investigated that the average specific energy consumption of the whole RO plant is around $3.5kWh/m^3$. The Busan Gi-jang plant has shown $3.7{\sim}4.0kWh/m^3$, including operational electricity for plant and maintenance building. Although not world top level, domestic RO technology is considered to be able to compete in desalination market. Separately, many researchers in the world are developing new technologies for energy savings. Various processes, forward osmosis (FO), membrane distillation (MD) process are expected to compete with RO in the future market. In Korea, FO-RO hybrid process, MD and pressure retarded osmosis (PRO) process are under development through the research program in Ministry of Land, Infrastructure and Transport (MOLIT). The desalination technology level is expected to decrease to $2.5kWh/m^3$.

• Journal of the Korean Solar Energy Society
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• v.30 no.3
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• pp.33-38
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• 2010

The evaporative desalination system using solar thermal energy would be the efficient and attractive method to get fresh water from brine due to low carbon dioxide generation. In this research the solar desalination system as a heating source of refrigerant R123 in the evaporator was considered. The circulation of refrigerant in the evaporator can reduce the energy consumption of the system, because of using the latent heat of the refrigerant 123 instead of the sensible heat of present hot water. The system was comprised of the single-stage fresh water production unit on the capacity of 1ton/day with shell and tube type evaporator, heaters instead of solar collector to supply the proper heat to refrigerant, and refrigerant and brine circulation systems. Various operating flowrate and temperature ranges were varied in the experiments to get the optimum design data. The results showed that the optimum flow rate of brine feed rate to evaporator was 1.2Liter/min, and the yield of fresh water was increased as higher temperature of feed brine. It was confirmed that the circulation flowrate of heating source of refrigerant was decrease of one fifth of the present warm water system, and very efficient system for solar desalination.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.3
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• pp.301-305
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• 2013

This study aims to design a portable desalination device and discusses the feasibility of the device for overcoming a shortage of safe drinking water. A low-energy, self-supporting, and portable desalination device is designed based on forward osmosis (FO) using an ammonium bicarbonate solution. Experiments with various concentrations of ammonium bicarbonate solution and sodium chloride solution showed that the portable desalination device's performance such as volume and flow rate of desalting water and time required satisfied drinking water standards. The device performance is controlled by varying the concentration and temperature of the solution.