• Journal of the Korea Society for Simulation
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• v.28 no.4
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• pp.1-10
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• 2019

The Sea Water Reverse Osmosis (SWRO) plant should take into account the availability of the plant from the design stage for long-term and continuous fresh water production. As it occurs, it is necessary to establish a corrective maintenance plan and preventive maintenance plan to maintain availability. In the field of complex engineering structures such as seawater desalination plants, it is difficult to estimate the reliability or availability of the system in a mathematical way. This study develops RAM analysis framework and model, and proposes discrete event simulation model as a application sowtware specialized for seawater desalination plant. Considering the characteristics of the plant maintenance, in case of corrective maintenance, we propose a preventive maintenance policy that not only repairs or replaces a single-broken part, but also simultaneously maintains all accessible parts according to the level of overhaul. A case study was conducted to estimate the availability of the system based on the field data of the seawater desalination plant in Korea and Saudi Arabia. The result was close to the expected availability of the plant.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.200-205
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• 2013

Pretreatment process is the critical step of RO (Reverse Osmosis) membrane desalination plant in order to prevent RO membrane fouling. The pretreatment as a key component of RO process must be designed to produce a constant and high quality RO feedwater which has low silt density index (SDI). This experiment was conducted to assess parameters affecting SDI value, such as pH, seawater turbidity, temperature, and coagulant dose. The experimental results indicated that the source seawater turbidity did cause little effects on SDI values of filtered water. The 0.45 um hydrophilic membrane was more appropriate than the hydrophobic membrane for measuring SDI. The SDI value was increased with decreasing pH under the condition of below pH 7.0. In addition, the water temperature significantly affected the SDI values, showing higher SDI value with lower water temperature.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.4
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• pp.357-361
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• 2018

Forward osmosis (FO) process has been attracting attention for its potential applications such as industrial wastewater treatment, wastewater reclamation and seawater desalination. Particularly, in terms of fouling reversibility and operating energy consumption, the FO process is assumed to be preferable to the reverse osmosis (RO) process. Despite these advantages, there is a difficulty in the empirical step due to the lack of separation and recovery techniques of the draw solution. Therefore, rather than using FO alone, recent developments of the FO process have adapted a hybrid system without draw solution separation/recovery systems, such as the FO-RO osmotic dilution system. In this study, we investigated the performance of the hollow fiber FO module according to various operating conditions. The change of permeate flow rate according to the flow rates of the draw and feed solutions in the process operation is a factor that increases the permeate flow rate, one of the performance factors in the positive osmosis process. Our results reveal that flow rates of draw and feed solutions affect the membrane performance, such as the water flux and the reverse solute flux. Moreover, use of hydraulic pressure on the feed side was shown to yield slightly higher flux than the case without applied pressure. Thus, optimizing the operating conditions is important in the hollow fiber FO system.

• Environmental Engineering Research
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• v.20 no.3
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• pp.285-289
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• 2015

Complicated and expensive seawater desalination technology is a big challenge in boron removal process. Conventional seawater desalination process of coagulation utilized for pre-treatment is difficult to remove boron. Boron can be removed more effectively in Reverse Osmosis (RO) process than any other processes. In this study, a coagulant with the name Mineral Cluster was examined its boron removal ability. Boron removal efficiency of Mineral Cluster depended on pH value and Mineral Cluster dosage. Desalination process combines the pre-treatment process with Mineral cluster diluted at the ratio of 1:2500 and the RO membrane process. The original sea water could be desalinated to drinking water quality, 1 mg/L, without any pH adjustments. Therefore, if the Mineral cluster is added without any other chemicals for adjusting pH, the desalination process would be much safer, efficient and economical.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.3
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• pp.271-278
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• 2016

Recently, reverse osmosis (RO) is the most common process for seawater desalination. A common problem in both RO and thermal processes is the high energy requirements for seawater desalination. The one energy saving method when utilizing the osmotic power is utilizing pressure retarded osmosis (PRO) process. The PRO process can be used to operate hydro turbines for electrical power production or can be used directly to supplement the energy required for RO desalination system. This study was carried out to evaluate the performance of both single-stage PRO process and two-stage PRO process using RO concentrate for a draw solution and RO permeate for a feed solution. The major results, were found that increase of the draw and feed solution flowrate lead to increase of the production of power density and water permeate. Also, comparison between CDCF and CDDF configuration showed that the CDDF was better than CDCF for stable operation of PRO process. In addition, power density of two-stage PRO was lower than the one of single-stage. However, net power of two-stage PRO was higher than the one of single-stage PRO.

• Proceedings of the Membrane Society of Korea Conference
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• 1998.04a
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• pp.80-82
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• 1998

1. 서론 : 우리나라의 총 3,167개의 도서중 유인도가 488이며, 경남 및 전남지역이 전체의 74%를 차지하고 있다. 전체 유인도중 가뭄시 상습적으로 식수난을 겪고 있는 도서는 237개에 이르고 있다. 이들 지역은 생활용수를 간이상수도, 우물, 운반수등에 의존하고 있으며 이중 111개 도서는 급수시설도 전무한 실정이다. (생략)

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.199-202
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• 2004

Membrane technology is widely employed as a means of producing various qualities of water from surface water, well water, brackish water and seawater. This is also used in industrial wastewater treatment and its recycling process. A large volume of wastewater is generated by the steel industry. Presently, the treated wastewater from the steel industry cannot be recycled, because some of its components cause either direct or indirect problems.(omitted)

• The KSFM Journal of Fluid Machinery
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• v.16 no.1
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• pp.61-65
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• 2013

Water is an integral part of energy production because it is used directly in many power generation systems such as hydroelectric power plants and thermoelectric power plants. Water is also used extensively in energy-resource extraction, oil, natural gas, and alternative fuels refining and processing. Recently, osmotic power systems using seawater and freshwater has been also investigated to produce electricity in a sustainable way. This study focused on the use of RO and PRO for the mutual conversion of water and energy. This system allows the production of water from seawater if there is not enough water. It can also generate electricity from salinity gradient of brine water and fresh water if there is not enough energy. To demonstrate the feasibility of this technology, a set of laboratory-scale experiments were carried out using a specially-designed RO/PRO system. The efficiency of energy conversion was theoretically estimated based on the results from the experiments. The results indicated that water and energy could be easily converted using a single device. Nevertheless, a lack of optimum membrane for this purpose was identified as a major barrier for practical application.

• Journal of the Korean Society of Systems Engineering
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• v.12 no.1
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• pp.73-87
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• 2016

Combining power generation and water production by desalination is economically advantageous. Most desalination projects use fossil fuels as an energy source, and thus contribute to increased levels of greenhouse gases. Environmental concerns have spurred researchers to find new sources of energy for desalination plants. The coupling of nuclear power production with desalination is one of the best options to achieve growth with lower environmental impact. In this paper, we will per-form a sensitivity study of coupling nuclear power to various combinations of desalination technology: {1} thermal (MSF [Multi-Stage Flashing], MED [Multi-Effect Distillation], and MED-TVC [Multi-Effect Distillation with Thermal Vapour Compression]); {2} membrane RO [Reverse Osmosis]; and {3} hybrid (MSF-RO [Multi-Stage Flashing & Reverse Osmosis] and MED-RO [Multi-Effect Distillation & Reverse Osmosis]). The Korean designed reactor plant, the APR1400 will be modeled as the energy production facility. The economical evaluation will then be executed using the computer program DEEP (Desalination Economic Evaluation Program) as developed by the IAEA. The program has capabilities to model several types of nuclear and fossil power plants, nuclear and fossil heat sources, and thermal distillation and membrane desalination technologies. The output of DEEP includes levelized water and power costs, breakdowns of cost components, energy consumption, and net saleable power for any selected option. In this study, we will examine the APR1400 coupled with a desalination power plant in the Kingdom of Saudi Arabia (KSA) as a prototypical example. The KSA currently has approximately 20% of the installed worldwide capacity for seawater desalination. Utilities such as power and water are constructed and run by the government. Per state practice, economic evaluation for these utilities do not consider or apply interest or carrying cost. Therefore, in this paper the evaluation results will be based on two scenarios. The first one assumes the water utility is under direct government control and in this case the interest and discount rate will be set to zero. The second scenario will assume that the water utility is controlled by a private enterprise and in this case we will consider different values of interest and discount rates (4%, 8%, & 12%).

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.285-291
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• 2011

Membrane fouling is an unavoidable phenomenon and major obstacle in the economic and efficient operation under sea water reverse osmosis (SWRO). When fouling occurs on the membrane surface, the permeate quantity and quality decrease, the trans-membrane pressure (TMP) and operation costs increase, and the membrane may be damaged. Therefore, chemical cleaning process is important to prevent permeate flow from decreasing in RO membrane filtration process. This study focused on proper chemical cleaning condition for Shuaibah RO plant in Saudi Arabia. Several chemical agents were used for chemical cleaning at different contact time and concentrations of chemicals. Also autopsy analysis was performed using LOI, FT-IR, FEEM, SEM and EDX for assessment of fouling. Specially, FEEM analysis method was thought as analyzing and evaluating tool available for selection of the first applied chemical cleaning dose to predict potential organic fouling. Also, cleaning time should be considered by the condition of RO membrane process since the cleaning time depends on the membrane fouling rate. If the fouling exceeds chemical cleaning guideline, to perfectly remove the fouling, certainly, the chemical cleaning is increased with membrane fouling rate influenced by raw water properties, pre-treatment condition and the point of the chemical cleaning operation time. Also choice of cleaning chemicals applied firstly is important.