Most recent developments in arsenic removal technology have been utilizing metal oxide nanoparticles such as CeO2, Fe3O4 and ZrO2 due to their larger surface area. However, there are several problems with arsenic removal using nanoparticles, such as water contamination and large pressure drop when using fixed-bed adsorbent. In this project, we discuss the preparation of CeO2 nanoparticles coated Fe3O4 loaded polycaprolactone microcapsules and their application in arsenic removal. Polyvinylpyrrolidone (PVP) was used as a surface modifier for uniform binding of the CeO2 nanoparticles without aggregation. The nanoparticles deposited on the microcapsules were smaller in size and less crystalline with the use of PVP. This feature was particularly important for higher arsenic adsorption efficiency. The microcapsule synthesized by solvent evaporation showed high adsorption capacity of 40 and 49 mg/g As III and V respectively. Fast removal of (>95%) As III and V at 10 ppm concentration range can be done within 15 minutes. Arsenic binding using these microcapsules was relatively insensitive to pH changes within a range of pH 3-11 for As III and pH 3-9 for As V. Fe3O4 nanoparticles loaded in the microcapsules also enabled magnetic separation for clean adsorbent material. In summary, CeO2 coated Fe3O4loaded PVP-modified polycaprolactone microcapsules can be useful at a wide range of pH as a clean adsorbent for both As III and V that do not leach nanoparticles to water.Acknowledgement: The author DS thanks the EWI Singapore for a PhD scholarship and technical support from Department of Chemistry, National University of Singapore.

Metal oxide incorporated microcapsules for arsenic removal

247th National Meeting (2014)

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