Synthesis of Hydrotalcite from Seawater and Its Application to Phosphorus Removal |
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| Authors: | Tomohito Kameda Toshiaki Yoshioka Miho Uchida Akitsugu Okuwaki |
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| Affiliation: | 1. Department of Applied Chemistry, Graduate School of Engineering , Tohoku University , Aoba 07, Aoba-ku, Sendai , 980-8579 , Japan;2. Institute of Multidisciplinary Research for Advanced Materials , Tohoku University , 1,1 Katahira, 2-Chome, Aoba-ku, Sendai , 980-8577 , Japan;3. Department of Applied Chemistry, Graduate School of Engineering , Tohoku University , Aoba 07, Aoba-ku, Sendai , 980-8579 , Japan |
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| Abstract: | 10.0 wt% milk of lime was added to seawater containing AlCl 3 at Mg/Al molar ratio of 3.0 until pH 10.5 with stirring, and kept at 25;C for 1 h. Hydrotalcite (HT) was precipitated as a single phase, and Mg 2+ and Al 3+ were quantitatively precipitated. The chemical composition was [Mg 0.75 Al 0.25 (OH) 2 ][(SO 4 ) 0.06 (Cl) 0.02 (OH) 0.11 *];0.27H 2 O* (*Balance). A 100 mg-P/L Na 2 HPO 4 solution and the HT were shaken at 25;C. Phosphate removal increased with increasing time and the HT quantity, and was the highest at pH 7-9. Phosphate ion could be quantitatively removed, adding 8 times the stoichiometric quantity of the HT at pH 8.7 for 6 h. |
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| Keywords: | Anion Exchange Hydrotalcite Milk Of Lime Phosphorus Removal Seawater Synthesis |
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