• 멤브레인
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• 제23권5호
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• pp.343-351
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• 2013

혼합 비료를 유도용액으로 하는 정삼투식 해수담수화에서 담수화 성능에 대한 유도용액 농도의 영향을 조사하였다. 혼합비료용액(DS)의 농도가 증가함에 따라 수투과선속은 거의 선형적으로 증가하였으나, PR (performance ratio)은 감소하였다. 또한 혼합비료용액의 농도가 600 g/L일 때, 해수 및 탈이온수를 각각 공급용액으로 하였을 경우 각각의 PR은 5.39 및 6.50이었다. 혼합비료용액의 농도가 증가함에 따라 N, P 및 K의 역용질선속은 거의 선형적으로 증가하였으나, 비역용질선속은 감소하였다. 역용질선속과 비역용질선속은 모두 질소(N) > 칼륨(K) > 인(P) 순으로 높게 나타났다.

• Membrane and Water Treatment
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• 제8권2호
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• pp.125-136
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• 2017

Reverse osmosis technology is being used on large scale for treatment of ground water, brackish water, wastewater and sea water. The most challenging issue in RO process is carbonate scaling which is directly linked with the efficiency and economy. Considering the natural phenomena of carbonate scaling different adaptations have been made to control scaling on the surface of RO membrane including acid dosage and antiscalant addition. As carbonate scaling is directly related with pH level of feed water, present study describes an experimental approach to reduce scaling on RO membrane by lowering the feed water pH by purging $CO_2$. In this comparative study four different conditions including control process (without any scale inhibitor), with dosage of antiscalant, with purging of $CO_2$ and with co addition of antiscalant and $CO_2$ in a feed stream line; it was established that $CO_2$ is a better appliance to reduce carbonate scaling on the membrane surface by reduce pH of feed stream. It was also observed that $CO_2$ and antiscalant mutually function better for scale control.

• 멤브레인
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• 제30권2호
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• pp.111-123
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• 2020

산업화와 기후 변화는 깨끗한 식수에 대한 수요 증가를 초래하였다. 막분리공정을 이용한 해수담수화는 물의 수요에 대한 요구를 채울 수 있는 경제적으로 실현 가능한 대안 중 하나이다. 막분리공정에서 2차원 재료들은 기존 역삼투분리막(reverse osmosis membrane) 기반의 폴리아마이드 박막복합막(TFC-PA)과 비교하였을 때 막의 강도를 높여주고 투수성을 용이하게 하며 높은 염제거율 및 높은 선속률과 선택성을 보여준다. 이 리뷰 논문에서는 재료, 합성, 특징, 해수담수화 과정을 기반으로 다양한 2차원 재료로 구성된 복합막들을 소개하고 있다.

• Environmental Engineering Research
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• 제20권1호
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• pp.99-104
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• 2015

The purpose of this study is to evaluate the performance of forward osmosis (FO) system for harvesting microalgae cultivated in secondary sewage effluent. Microalgae species used in this study were chlorella sp. ADE4. The drawing agents used for forward osmosis system were seawater and concentrate of sea water reverse osmosis (SWRO) system. Chlorella sp. ADE4 cultured in secondary sewage effluent illustrated moderate efficiency in removal of total nitrogen (TN) (68%) and superior performance in total phosphorus (TP) removal (99%). Comparison of seawater and SWRO concentrate as drawing agent were made in FO membrane separation of the microalgae. The result from this study depicts that SWRO concentrate is strong drawing agent in FO membrane system providing an average dewatering rate of $4.8L/(m^2{\cdot}hr)$ compared to seawater with average dewatering of $2.9L/(m^2{\cdot}hr)$. Results obtained from this study indicated that FO system could be viable option for harvesting the microalgae for further biodiesel production. SWRO concentrate as a drawing agent could be very important finding in field of membrane technology for disposal of SWRO concentrate.

• 한국시뮬레이션학회논문지
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• 제28권4호
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• pp.1-10
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• 2019

해수담수화(SWRO, Sea Water Reverse Osmosis) 플랜트는 장기적이고 지속적인 담수 생산을 위하여 설계단계부터 플랜트의 가용도를 고려하여야 하며, 시간의 흐름에 따라 다양한 형태의 노후 현상이 진행되어 시스템 성능의 저하가 발생하므로 가용도 유지를 위한 고장정비 및 예방정비 계획 수립 등이 필요하다. 해수담수화 플랜트와 같이 복잡한 공학구조로 구성된 플랜트 분야에서는 시스템의 신뢰도 혹은 가용도를 수리적인 방법으로 추정하는데 어려움이 있다. 본 연구는 해수담수화 플랜트에 특화된 소프트웨어 개발을 위하여, RAM 분석 프레임워크와 모델링 방법을 개발하고, 가용도 산출을 위한 이산사건 시뮬레이션 모델을 제안한다. 플랜트 정비의 특성을 고려하여 고장 정비 발생 시, 단일 부품의 수리/교체 뿐만 아니라 분해 정비 수준에 따라 접근 가능한 모든 부품을 동시 정비하는 예방정비 정책을 제안하고, 제안된 방법론에 따라 시뮬레이션 모델 및 프로토타입을 개발하였다. 이를 활용하여 국내외에 건설된 해수담수화 플랜트의 현장 데이터를 기반으로 시스템의 가용도 및 가동률 등을 추정 사례 연구를 수행하였고, 그 결과 실제 플랜트의 가용도와 근접한 결과를 얻었다.

• 멤브레인
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• 제25권2호
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• pp.132-143
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• 2015

인구의 급속한 증가, 한정된 식수 자원의 오염 등으로 인하여 인류에게 필수적인 물이 점점 부족해지고 있다. 깨끗한 물을 얻기 위해 분리막 공정을 이용한 수처리 방식이 널리 사용되고 있으며, 분리막 공정 중 하나인 정삼투 공정은 고압펌프 없이 구동이 가능하다. 정삼투 공정이 높은 수투과도를 가지기 위해서는 내부 농도 분극 현상 및 Reverse salt flux를 적게 일으키는 유도 용질 개발이 필요하며, 희석된 유도 용액에 포함된 유도 용질의 경제적인 회수 방법 개발 또한 필요하다. 현재까지는 $60^{\circ}C$ 가량에서 회수가 가능한 $NaHCO_3$와 같은 무기 유도 용질, 음료수 생산이 가능한 sucrose와 같은 유기 유도 용질, 자기장을 이용해 회수가 가능한 magnetic nanoparticle과 같은 유도 용질들이 개발되어 보고되었다. 또한, 이러한 정삼투 원리를 이용하여 해수 담수, 폐수처리, 단백질 정제, 압력 지연 삼투 이용한 에너지 생산, 관개를 위한 농축된 비료 희석, 바이오 연료를 위해 폐수로부터 조류를 키우는 공정과 같은 분야에 적용될 수 있다. 본 논문에서는 정삼투 공정에 영향을 주는 유도용액의 특성과 이상적인 조건, 여러 가지 유도 용질 및 유도용질의 회수 방법, 정삼투 공정의 적용 분야를 여러 논문 내용들을 바탕으로 정리하였다.

• 유공압시스템학회논문집
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• 제4권3호
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• pp.7-12
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• 2007

This paper presents an energy saving hydrostatic pressure exchanger for sea water desalination equipment. In a reverse osmosis(RO) system for desalinating sea water, more than 70 percent of the supplied sea water, brines which were impassable through RO membrane are bypassed, resulting in high energy losses. In this paper, a hydrostatic pressure exchanger consisting of an embedded water hydraulic piston motor and a water hydraulic piston pump was proposed and investigated in order to recover the energy of the bypassed brines. The pressurized brines are supplied to the embedded water hydraulic piston motor as power sources and the water hydraulic piston pump is driven by the output torque of the embedded water hydraulic piston motor as well as electric motor. Consequently, the energy of the bypassed brines can be recovered. To examine the electric energy saving characteristics of the hydrostatic pressure exchanger, a simulation model was constructed using commercial software and experiments were conducted. Through the results of simulation and experiment, the feasibility of the electric energy saving effect of the proposed hydrostatic pressure exchanger was investigated.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.11-14
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• 1998

1. Introduction : Research progresses in Chemistry and Chemical Engineering have been made during the last decades with important contributions to the industrial development and to the quality of our life. An interesting case is related to the membrane science and technology continuous impact to innovative processes and products, particularly appropriate for a sustainable industrial growth. Membrane operations have been familiar for many years to biologists and chemists working in their laboratorier or studying biological phenomena. Only recently engineers started to operate in' this area. The preparation of asymmetric CA membranes at University of California, Los Angeles in the early 60s is generally recognized as a crucial moment for membranology (1). Loeb and Sourirajan with their discovery of how to increase significantly the permeability of polymeric membranes without significant changes in their selectivity, made realistic the possibility of their use in large scale operations for desalting brackish and sea water by reverse osmosis and for various other molecular separations in different industrial areas. Reverse osmosis is today a well recognized basic unit operations, togheter with ultrafiltration, crossflow microfiltration,. nanofiltration, all pressure driven membrane processes. Already in 1992 more than 4 milIions m$^3$/day were the total capacity of RO desalination plants and in 1995 more than 180.000 m$^2$ of ultrafiltration membranes were installed for the treatment of wheys and milk (2) (3).

• Membrane and Water Treatment
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• 제8권3호
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• pp.279-292
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• 2017

This study was aimed at ultrafiltration (UF) as a pretreatment before reverse osmosis (RO) within the scheme of hybrid reverse osmosis-multistage flush (RO-MSF) desalination. Seawater at elevated temperature (after MSF heat-exchangers) was used as a feed in this process. The pretreatment system was represented as a set of functionally-linked technological segments such as: UF filtration, backwashing, chemical- enhanced backwashing, cleaning, waste disposal, etc. The process represents the sequences of operating cycles. The cycle, in turn, consists of the following unit operations: filtration, backwashing and chemical-enhanced backwashing (CEB). Quantitative assessment was based on the following indicators: normalized permeability, transmembrane pressure, specific energy and water consumption, specific waste generation. UF pre-treatment is accompanied by the following waste streams: $W1=1.19{\times}10$ power of $-2m^3$ (disposed NaOCl with 0.0044% wt.)/$m^3$ (filtrate); $W2=5.95{\times}10$ power of $-3m^3$ (disposed $H_2SO_4$ with 0.052% wt.)/$m^3$(filtrate); $W3=7.26{\times}10$ power of $-2m^3$ (disposed sea water)/$m^3$ (filtrate). Specific energy consumption is $1.11{\times}10$ power of $-1kWh/m^3$ (filtrate). The indicators evaluated over the cycles with conventional (non-chemical) backwashing were compared with the cycles accompanied by CEB. A positive impact of CEB on performance indicators was demonstrated namely: normalized UF resistance remains unchanged within the regime accompanied by CEB, whereas the lack of CEB results in 30% of its growth. Those quantitative indicators can be incorporated into the target function for solving different optimization problems. They can be used in the software for optimisation of operating regimes or in the synthesis of optimal flow- diagram. The cycle characteristics, process parameters and water quality data are attached.

• Journal of Animal Science and Technology
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• 제52권3호
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• pp.213-220
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• 2010

This study was executed to investigate the effects of drinking deep sea water treated by reverse osmosis process (RO-DSW) on growth performance, nutrient utilizability, relative weight of lymphoid organs and the concentration of serum immunoglobulin G (IgG) in broiler chickens. A total of 200 one day old broiler chickens (Ross 308) were equally and randomly distributed into 10 ground floor pens (20 chicks per pen, 5 pens per treatment) bedded with rice-husks. The broilers were offered either fresh tap water (Control) or RO-DSW for 28 days (from d 6 to d 33) as the drinking water. The same basal phase 1 diet for first 2 weeks and phase 2 diet for last 2 weeks were offered ad libitum to the birds. The RO-DSW was prepared by diluting 1:20 ratio with deionized water before offering to chickens. The diet for control birds was supplemented with 0.21 % of food-grade salt to satisfy salt need of the birds. Broiler feeding study resulted that there were no differences in amount of water consumption, mortality and FCR between RO-DSW and control chickens. However, feed intake and body weight gain were increased (p<0.05) by RO-DSW drinking. There was no (p>0.05) difference in nutrients utilizability between RO-DSW and fresh water drinking. There were no (p>0.05) differences in the immune response between the control and treatment group. The serum IgG levels were 3.01 vs 2.87 mg/ml and the relative weights of spleen, thymus and bursa of Fabricius were 0.23, 0.18 and 0.20 vs. 0.20, 0.17 and 0.14 for RO-DSW vs. control birds, respectively. The immune responses were tended to be improved by RO-DSW drinking. This study showed an improvement in weight gain and feed intake that could be induced by RO-DSW drinking, although it is difficult to explain the reasons of the improvement at this moment. This study implied that RO-DSW could be successfully used as drinking water to broiler chickens.