• Journal of Korean Society of Environmental Engineers
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• v.38 no.1
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• pp.34-41
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• 2016

Using UF-SWRO hybrid process, pre-blending tests of seawater and brackish water were performed to investigate the effects on removal of boron and humic acid (HA). Feedwater pre-blending was set based on TDS concentration from 15,000 mg/L to 27,000 mg/L and analyzed for boron removal characteristics. Also organics rejection at same TDS concentration range was investigated by injecting HA. Boron concentration appeared to be high as TDS concentration was high ranging from 76.60% to 83.27%, but boron concentration in final produced water was increased up to 0.69 mg/L from 0.48 mg/L. In cases of HA tests at 10 mg/L, 22,500 mg/L TDS appeared to be higher removal rate of 17.59% than a very poor result of 8.43% in 27,000 mg/L. But high HA removal rate of 57.14% was obtained in produced water with 22,500 mg/L TDS containing 10 mg/L of HA and 27,000 mg/L TDS yielded lower boron removal rate of 54.49%. Meanwhile it was found that a relatively high flux and recovery rate were obtained following process when feedwater was injected with HA. It is considered that most of fouling substances were eliminated by binding between HA and $Ca^{2+}$. Thus, when desalination using UF-SWRO with respect to boron and HA, TDS concentration is determined to be advantageous as lower.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.6
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• pp.771-778
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• 2013

Gas hydrate (GH) process is a new desalination technology, where GH is a non- stoichiometric crystalline inclusion compounds formed by water and a number of gas molecules. Seawater GH is produced in a low temperature and a high pressure condition and they are separated from the concentrated seawater. The drawback of the GH process so far is that salt contents contained in its product does not meet the fresh water quality standard. This means that the GH process is not a standalone process for seawater desalination and it needs the help of other desalting process like reverse osmosis (RO). The objective of this study is to investigate the effect of GH process on energy saving for RO process in seawater desalination. The GH product water quality data, which were obtained from a literature, were used as input data for RO process simulation. The simulation results show that the energy saving effect by the GH process is in a range of 68 % to 81 %, which increases as the salt removal efficiency of the GH process increases. Boron (B) and total dissolved solids (TDS) concentrations of the final product of the hybrid process of GH and RO were also investigated through the RO process simulation to find relavant salt rejection efficiency of the GH process. In conclusion, the salt rejection efficiency of the GH process should exceed at least 78% in order to meet the product water quality standards and to increase the energy saving effect.

• JOURNAL OF ELECTRICAL WORLD
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• s.410
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• pp.48-53
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• 2011

발전 및 플랜트 분야의 '청정 산소탱크' 두산중공업. 명장(明匠)은 명품(名品)을 낳고, 이렇게 만들어진 두중의 명품은 지구와 인류의 가치를 드높이고 있다. 발전과 Water사업 분야의 다양한 명품들을 제작해 내고 있는 두중 창원공장. 최첨단 친환경 고효율 발전기술을 보유한 두중은 국내에서 가동 중인 20기의 원전 중 16기에 주기기 공급, HRGS(배열회수보일러) 세계시장 점유율 1위, 자타공인 해수담수화 분야 세계 넘버 원 기업이다. 또한 지난 20년간 세계에서 가장 많은 원전 주기기 공급뿐만 아니라 중국 최초의 3G 원전인 산먼, 하이양 원전 수주, 미국에서 발주된 6기의 AP1000 주기기 전량을 수주하는 기록을 달성하기도 했다. 여기에 더해 최근 두산중공업은 풍력발전 등 신재생에너지 분야와 CCS 등 친환경발전 분야의 기술 상용화부문에서도 가속도를 내고 있다. 일관성과 원칙을 중시하는 박지원 사장의 진두지휘 하에 '경쟁우위의 지속'을 지향하는 두중의 글로벌 가치제고 노력은 여전히 현재 진행형이고, 미래지향적이다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.1
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• pp.64-69
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• 2011

A novel concept of the gridable desalination plant is to provide an operation management to enable an electricity plant operation cost reduction. Adjusting recovery rate responded to electricity price, an electricity plant operation cost can be saved. To show a suggested approach, the data of 10 [MIGD](Million Imperial Gallons per Day) SWRO testbed are used. The result shows that total cost reduction rate is calculated about 1.6[%] of annual total electric plant operation cost.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.573-579
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• 2011

As rapid advances in technologies continue, seawater reverse osmosis (SWRO) desalination systems are now more energy-efficient than conventional thermal processes. Some SWRO desalination plants can achieve the specific energy consumption (SEC) below 2 kWh/$m^3$. Along with the development of new membranes and high-performance pumps, energy recovery devices (ERD), which recover the hydraulic energy of brine, have been developed to enhance energy efficiency. In this work, we reviewed general aspects of ERD technologies and their market trends. The advantages and disadvantages of various EDR technologies were compared to explore the future directions of ERD development.

• Membrane Journal
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• v.30 no.3
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• pp.190-199
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• 2020

The utilization of multiple water sources becomes important due to the master plan for development of water supply released by Ministry of Environment, Korea in 2018. In this study, therefore, the analysis of comprehensive effect in blending applicable water sources in Daesan where 100,000 ㎥/d seawater desalination plant will be constructed for industrial use was performed. The increase in mixing ratio of other water sources with seawater reduced salinity up to 50%, but negatively impacted the turbid and organic matter. Lab-scale reverse osmosis performance test also found that membrane fouling was exacerbated in blended water condition. The simulation results of reverse osmosis indicated 39% energy saving on average is expected at the one-to-one blending ratio, however, long-term performance test at the pilot-scale plant is highly required to evaluate the inclusive impact of mixing seawater and other water sources.

• 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.

• Journal of Korean Society for Quality Management
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• v.48 no.1
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• pp.171-186
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• 2020

Purpose: The purpose of this study is conducting of predictive models that considered multicollinearity of independent variables in order to carry out more efficient and reliable predictions about differential pressure in seawater reverse osmosis. Methods: The main variables of each RO system are extracted through factor analysis. Common variables are derived through comparison of RO system # 1 and RO system # 2. In order to carry out the prediction modeling about the differential pressure, which is the target variable, we constructed the prediction model reflecting the regression analysis, the artificial neural network, and the support vector machine in R package, and figured out the superiority of the model by comparing RMSE. Results: The number of factors extracted from factor analysis of RO system #1 and RO system #2 is same. And the value of variability(% Var) increased as step proceeds according to the analysis procedure. As a result of deriving the average RMSE of the models, the overall prediction of the SVM was superior to the other models. Conclusion: This study is meaningful in that it has been conducting a demonstration study of considering the multicollinearity of independent variables. Before establishing a predictive model for a target variable, it would be more accurate predictive model if the relevant variables are derived and reflected.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.2
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• pp.216-222
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• 2021

This is an experiment to complement new ways of using concentrated water discharged from the seawater desalination plant. In this study, metakaolin, which has excellent chloride ion immobilization effect, was used as the main binder, and 10% and 20% of calcium oxide were substituted with the activator. In addition, tap-water(TW) and reverse osmosis brine water(RW) were used as mixed water. As a result of the experiment, the mixture using RW showed higher compressive strength than TW. It also showed low water absorption and high density. In the mixture using RW as mixed water, a hydration reaction substance called Friedel's salt could be observed. Considering the corrosion problem of steel, RW is considered to be applicable to products such as non-reinforced concrete, brick, and curb stone. Through this study, it is thought that it is meaningful to propose a new application method other than the ocean release of RW.

• Journal of Korean Society on Water Environment
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• v.27 no.2
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• pp.178-187
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• 2011

National water supply, water resources available, the ratio of water supply to total water resources, and the ratio of water supply to available water resources were investigated to find global seawater desalination plant market for 163 nations. Water resources available per capita from 2007 to 2016, population in water scarcity region from 2011 to 2016, and the ratio of water scarcity population to total population were also analyzed for the countries. Annual percentage increase in total municipal drinking water capital expenditure and Annual percentage increase in total industrial water market were analyzed to predict the amount of water supply by use. 76 countries are suffering from water scarcity and 60 countries among the countries have coastal regions. Forty countries were selected by considering the considerable amount and highly increasing trend of water demand by use. Most countries show increasing trend of industrial water and 82 countries have more than 4% annual increasing rate for domestic water expense from 2008 to 2016 among 163 countries. Among the 76 water scarcity countries 16 countries were finally selected by considering expense prediction by use. Middle-east, east asia, pacific ocean, and west europe regions include most selected countries.