Ceria-Coated Nanostructured Magnetite Materials For Arsenate Removal

The discharge of heavy metal ions such as arsenic (As) into drinking water sources either through natural or anthropogenic activities is a serious health and lifethreatening issue. Hence, surface-modified Fe 3O 4 particles are one of adsorbents for cleaning As contaminated water that is being resear...

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Bibliographic Details
Main Author: Devaraj, Nisha Kumari
Format: Thesis
Published: 2019
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Summary:The discharge of heavy metal ions such as arsenic (As) into drinking water sources either through natural or anthropogenic activities is a serious health and lifethreatening issue. Hence, surface-modified Fe 3O 4 particles are one of adsorbents for cleaning As contaminated water that is being researched extensively due to its favourable magnetic properties. Numerous types of coating have been reported to enhance the adsorption efficiency; however studies detailing the usage of ceriacoated-Fe 3O 4 particles are scarce. Furthermore, elucidating effects of experimental parameters such as stirring rate and stirring time on the particle properties is important in the design of nanoparticles with high adsorption efficiency. In this study, Fe 3 O 4 particles were synthesised using co-precipitation method followed by coating with titania and ceria under varying experimental parameters to obtain particles of different average sizes and size distributions. The synthesised particles were subsequently characterised by various characterisation equipment to investigate their properties. It is evident from the Dynamic Light Scattering (DLS) measurements that the layer of surface coating had helped reduced agglomeration and dipole-to-dipole interaction between the particles. Based on the X-ray Diffractometer (XRD) profiles, it can be deduced that Fe 3O 4, titania-coated and ceriacoated Fe 3 O 4 nanoparticles were successfully synthesised. The particles also displayed superparamagnetic behaviour, which is necessary for ease of particle separation from water after the adsorption process. As for the As(V) removal performance, the molybdenum blue-based colorimeter method was used. A calibration curve using As(V) sample solutions with known concentrations depicted a linear relationship between the concentrations and their corresponding peak absorbance values. Results indicated that the titania-coated Fe 3O 4 particles were able to remove 100% of As(V) in the solution after a contact time of 4 hours. For the uncoated and ceria-coated Fe 3O 4 particles, a dosage of 0.1 g and temperature of 50°C was found to be yield higher adsorption capacities for most of the samples. No correlation could be drawn between the particle sizes and their removal performance.