• Journal of Korean Society of Environmental Engineers
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• v.38 no.6
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• pp.291-298
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• 2016

Electrochemical water treatment process as a useful treatment method for the removal of non-degradable matter has been consistently studied for several decades. Key process of electrochemical water treatment are oxidation reaction from an anode and reduction from a cathode. In this study, the effect of pre-treatment methods in the insoluble electrode manufacturing process for the water treatment has been evaluated for the life time of electrode The results of this study showed that pre-treatment methods of a base metal such as surface roughness, clean method and interlayer formation influenced to life time of electrode when the same condition (catalyst electrode layer coating method and material system) was applied for pre-treatment methods. This study was conducted by using $IrO_2/Ti$ electrode In the test of sand-blasting process, an electrode manufactured by using sanding media of different sizes resulted in the most effective electrode life time when the size of alumina was used for $212{\sim}180{\mu}m$ praticle size (#80). The most effective method was considered using arc plasma in the additional roughness control and cleaning process, sputtering method to form Ta type interlayer formation process.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.2
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• pp.60-66
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• 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