• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2904-2912
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• 2011

Water qualities in the decentralized water treatment plants do not frequently satisfy the water standard limit, in particular, fluoride and nitrate are notorious for the poor removal. In this study, an electro-adsorption equipped with carbon nonotube (CNT) electrodes were carried out to effectively remove the nitrate and fluoride in the decentralized water treatment plants. Two types of CNT electrodes, coating and sintering electrodes were applied. Coating electrodes were made based on different kinds of binder and sintering electrodes were made based on different sintering temperature. Removal of fluoride and nitrate when the coated electrodes with organic binder were used for electro-adsorption were 46 and 99.9% respectively, which were better performances than the coated electrodes with inorganic binder were used. On the other hand, removal of fluoride and nitrate when the electrodes sintered at higher temperature ($1,000^{\circ}C$) were 77 and 87% respectively, which were better performances than the electrodes sintered at lower temperature ($850^{\circ}C$). As a consequences, the electro-adsorption equipped with a CNT electrodes could be an potential alternative process for the removal of fluoride and nitrate in a decentralized water treatment plants if proper current density and contact time were applied.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1222-1225
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• 1997

A gaseous oxygen detector has been developed in a configuration of Pd-$SnO_x$-$Si_3N_4$-$SiO_2$-Si-Al with highly resistive $SnO_x$ layer as the oxygen adsorptive element. In this paper, we present the characteristics of the device in response to oxygen adsoption/desorption under applied d.c. bias. Experimental results showed that the oxygen adsorptive response by the device was reduced significantly under a positive gate bias, for all experimental regions of $O_2$ partial pressure. On the other hand, the application of a negative gate bias increased the device's adsorptive response of oxgyen. A device model concerning this electroadsorption/desorption behavior of the device is provided.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.4
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• pp.2027-2036
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• 2013

Comparison of removal performance between reverse osmosis(RO), nanofiltration(NF), electrocoagulation(EC) and electroadsorption(EA) for removal of nitrate and fluoride often exceeded the limits of water quality in small water treatment plants. Removals of nitrate and fluoride were 72-92% and 74-85% in RO, 5-15% and 1% in NF, 99% and 44% in EA equipped with MWCNT coated electrodes, 82% and 77% in EA equipped with Cu-MWCNT electrodes, and 11-46% and 69-99% in EC. Consequently, high removals of both ions were anticipated in RO. Effective removal of both ions are possible for EC, but great production of sludge is a big burden. EA equipped with the MWCNT electrodes showed a great fluctuation in removal efficiency, and electrode stability should be upgraded.