• Title/Summary/Keyword: mesoporous $TiO_2$ adsorbent

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Adsorption kinetics and isotherms of phosphate and its removal from wastewater using mesoporous titanium oxide

  • Lee, Kwanyong;Jutidamrongphan, Warangkana;Lee, Seokwon;Park, Ki Young
    • Membrane and Water Treatment
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    • v.8 no.2
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    • pp.161-169
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    • 2017
  • The adsorption of phosphate onto mesoporous $TiO_2$ was investigated in order to reduce phosphorus concentrations in wastewater and provide a potential mode of phosphorus recovery. Three equilibrium isotherms were used to optimize and properly describe phosphate adsorption ($R^2$>0.95). The maximum capacity of phosphate on the adsorbent was found to be 50.4 mg/g, which indicated that mesoporous $TiO_2$ could be an alternative to mesoporous $ZrO_2$ as an adsorbent. A pseudo-second order model was appropriately fitted with experimental data ($R^2$>0.93). Furthermore, the suitable pH for phosphate removal by $TiO_2$ was observed to be in the range of pH 3-7 in accordance with ion dissociation. In contrast, increasing the pH to produce more basic conditions noticeably disturbed the adsorption process. Moreover, the kinetics of the conducted temperature study revealed that phosphate adsorption onto the $TiO_2$ adsorbent is an exothermic process that could have spontaneously occurred and resulted in a higher randomness of the system. In this study, the maximum adsorption using real wastewater was observed at $30^{\circ}C$.

Study on the Enhanced Specific Surface Area of Mesoporous Titania by Annealing Time Control: Gas Sensing Property (열처리 시간에 따른 메조기공 타이타니아의 비표면적 향상 연구: 가스센싱 특성 변화)

  • Hong, M.-H.;Park, Ch.-S.;Park, H.-H.
    • Journal of the Microelectronics and Packaging Society
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    • v.22 no.2
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    • pp.21-26
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    • 2015
  • Mesoporous ceramic materials were applied in various fields such as adsorbent and gas sensor because of low thermal conductivity and high specific surface area properties. This structure could be divided into open-pore structure and closed-pore structure. Although closed-pore structure mesoporous ceramic materials have higher mechanical property than open-pore structure, it has a restriction on the application because the increase of specific surface area is limited. So, in this work, specific surface area of closed-pore structure $TiO_2$ was increased by anneal time. As increased annealing time, crystallization and grain growth of $TiO_2$ skeleton structured material in mesoporous structure induced a collapse and agglomeration of pores. Through this pore structural change, pore connectivity and specific surface area could be enhanced. After anneal for 24 hrs, porosity was decreased from 36.3% to 34.1%, but specific surface area was increased from $48m^2/g$ to $156m^2/g$. CO gas sensitivity was also increased by about 7.4 times due to an increase of specific surface area.