2019 Fiscal Year Annual Research Report
Removal of arsenic from groundwater using a composite of cationic hydrogel and iron hydroxide
| Project/Area Number |
19J22780
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| Research Institution | Hiroshima University |
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Principal Investigator |
Safi SyedRagib 広島大学, 工学研究科, 特別研究員(DC1)
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| Project Period (FY) |
2019-04-25 – 2022-03-31
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| Keywords | Arsenic / Adsorption / Groundwater / Polymer gel / Iron hydroxide |
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| Outline of Annual Research Achievements |
The highest amount of adsorption of As (III) by DMAPAAQ + FeOOH gel was 27.68 mg/g and the adsorption followed the Langmuir isotherm. The gel selectively adsorbed As (III) with the presence of co-existing sulphate and chloride ions of upto 20 mM. The reusability of DMAPAAQ + FeOOH gel for adsorption of As (III) and As (V) for eight complete consecutive cycles could be achieved, with the same pieces gel being used throughout the eight cycles. TEM images showed that there were 6-13 nm of iron particles in the gel structure. Also, there was 62.01 wt% of iron hydroxide contents in the gel, suggested by TG analysis. XRD analysis suggests that the polymer structure of the DMAPAAQ + FeOOH gel is amorphous. The adsorption mechanism for both As (III) and As (V) were confirmed by XPS analysis.
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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
The results of our research, removal of As (V) using a composite of polymer gel and iron hydroxide, were published in two renowned international journals. Also, we made an oral and two poster presentations at two international conferences. Moreover, we achieved an Excellent Poster Award. Currently, we are conducting the research on removal of As (III), which is more difficult to remove because it is hard to oxidize. Although we fulfilled our objectives, we could have achieved more if we had the instrument to detect As(III) and As(V) separately. Because of not having the instrument, we invested our time to finding an alternative. For this reason, we could not progress after autumn as much as we originally planned. We hope to find a solution soon and make good progress in 2020.
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| Strategy for Future Research Activity |
In future, our plan is to examine the conversion of rate between As(III) and As (V) during the adsorption process. Also, we will study the increase in oxidation of As (III) into As (V). Our first specific objective to fulfill the plan is to find the proper instrument to accurately and specifically measure As (III) and As (V) separately. This step is important to measure the amount of As(III) being oxidized into As (V). In addition, we will examine, the increase of amount of As(III) being oxidized because of using our gel, DMAPAAQ + FeOOH. Our broad objective is to focus on increasing the adsorption amount of total arsenic.
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