• Title/Summary/Keyword: 해수역삼투

Search Result 93, Processing Time 0.023 seconds

Development of minimum-salinity feedwater for reduction of unit production cost of reverse-osmosis desalination plants (역삼투 담수화 시설의 생산단가 절감을 위한 저 염도 지하 기수 개발)

  • Park, Namsik;Jang, Chi Woong;Babu, Roshina
    • Journal of Korea Water Resources Association
    • /
    • v.49 no.5
    • /
    • pp.431-438
    • /
    • 2016
  • Large energy consumption is one of the main weaknesses of RO desalination. A new method is proposed to reduce the energy consumption of RO desalination which depends on the salinity of the feedwater. Low salinity feedwater can be obtained using groundwater wells which extracts both fresh groundwater and subsurface sea water. Subsurface feedwater is advantageous in overcoming other problems associated with surface seawater intakes. Salinities of groundwater depend on a number of factors. In this work a new simulation-optimization model is proposed to identify well locations and pumping rates with would provide the required design flow rate with the minimum salinity. When groundwater is developed in a coastal area, the saltwater wedge advances inland and may contaminate existing groundwater wells, which must be prevented. The model can protect existing wells while developing minimum salinity feedwater. Examples are provided to demonstrate the usage of the model.

Efficiency Estimation for Desalination System of Seawater Using Reverse Osmosis Membrane (역삼투압막 해수담수화 장치의 미네럴 분리 성능평가)

  • Moon, Deok-Soo;Jung, Dong-Ho;Kim, Hyeon-Ju;Shin, Phil-Kwon
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.8 no.2
    • /
    • pp.60-66
    • /
    • 2005
  • When external pressure higher than osmosis pressure is reversely derived into solution, its solvent is moved into the solution having lower concentration, which is called 'reverse osmosis'. We investigated the desalination application of deep ocean water using reverse osmosis pressure of $40-70\;kgf/cm^2$ We observed how to operational factor j like flow rate, water temperature and pressure have effect on efficiency of reverse osmosis membrane and salts rejection. Fluxes of reverse osmosis membrane are directly proportional to water temperature and pressure. However, salts rejection rates are positively correlated with pressure and inversely proportional to water temperature. Separation efficiencies of osmosis membrane for major elements such as $Mg^{2+},\;Ca^{+2},\;Na^+\;and\;K^+$ are as follows in a strong electrolysis solution like seawater; $Ca^{2+},\;Mg^{2+}>K^+>Na^+$. Rejection rates of $Mg^{2+}\;and\;Ca^{2+}$ that have high electric charges are over 99% and show positively correlation with water temperature. Rejection rates of $Na^+$ having low electric charge is observed to be 98%-99%, which rates is much lower than those of $2^+$ charged ions like $Ca^{2+}\;and\;Mg^{2+}$. Ion rejection rates of boron, B, are much low because boron is present il free state or gas phase in seawater. Boron concentration in desalination water is over criteria of Korean drinking water, 0.3 mg/L. However, we could satisfied with the criteria of drinking water under the operation condition like temperature $5^{\circ}C$ and pressure $70kgf/cm^2$, using the relationship that rejection rates of boron is proportional to pressure and is inversely proportional to water temperature

  • PDF