2016 Fiscal Year Annual Research Report
ヒ素およびフッ素除去のための機能性吸着剤の化学設計
| Project/Area Number |
16F16082
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| Research Institution | Kyushu University |
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Principal Investigator |
笹木 圭子 九州大学, 工学研究院, 教授 (30311525)
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| Co-Investigator(Kenkyū-buntansha) |
SUBBAIAH MUTHU PRABHU 九州大学, 工学研究院, 外国人特別研究員
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| Project Period (FY) |
2016-10-07 – 2019-03-31
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| Keywords | HSAB principle / adsorption / biopolymer |
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| Outline of Annual Research Achievements |
The approach to search a single-adsorbent for both AsO33- and F- removal is based on application of the hard-soft acids base (HSAB) concept, and also on exploring the suitability of sucrose derived porous carbon (PSC). Amorphous ZrOOH, LaOOH, ZrxLa1-xOOH and ZrxLa1-xOOH prepared by chemical co-precipitation were homogeneously dispersed into PSC. The ZrxLa1-xOOH and PSC-ZrxLa1-xOOH composite materials showed both fast adsorption rates and high adsorption capacities towards AsO33- and F- in aqueous solution. ZrxLa1-xOOH and PSC-ZrxLa1-xOOH showed better F- adsorption capacity at pH < 7, better AsO33- removal at pH > 9 and were superior to previously reported metallic oxide-based sorbents. The mechanism can be interpreted based on the HSAB principle, where the bimetallic oxyhydroxides become SA, while La3+ and Zr4+ are categorized as HA. Moreover, the PSC-ZrxLa1-xOOH adsorbent demonstrated high selectivity for AsO33- in the co-existence of other ions in a triple component system. Also, biopolymer, chitosan (CS) is an aqueous-stable biopolymer derived from insect and shellfish exoskeletons and it possesses surface rich in -OH and -NH2 groups, useful for bonding transition metal ions through chelation which helps to enhance the adsorption capacity of several toxic ions. Chemical precipitation method was employed to synthesize ZrOOH, AlOOH, ZrxAl1-xOOH and CS@ ZrxAl1-xOOH and tested for simultaneous removal of AsO33- and F-. The CS@ZrxAl1-xOOH adsorbent may form borderline character, and this may be responsible for adsorption of AsO33- and F- through HSAB principle.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
One manuscript regarding of the above results has been submitted and under review at the moment.
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| Strategy for Future Research Activity |
1)Synthesis of La based MOF materials and their uptake performance of F- and AsO33- from single and binary systems
2)Graphene based magnetic nanocomposites for functionalized biopolymer for simultaneous adsorption of F- and AsO33-.
3)Synthesize of ligand-functionalized biopolymer for simultaneous adsorption of both F- and AsO33-.
4)Surfactant assisted mixed oxide onto biochar for simultaneous adsorption of F- and AsO33-.
5)Preparation of magnetic coated ZrO2 @polyamidoamine (PAMAM) dendrimer for F- and AsO33- adsorption from single and binary systems. Evaluation of their uptake mechanism, and understanding of the reduction pathways by different analyses such as EXAFS and XPS.
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