Arsenate Removal Performance of Magnetite Nanoparticles

The drive towards Industry 4.0, while beneficial for efficient production and economic growth, may also bring about detrimental effects on the environment. Amongst the most likely effect is increased discharge of wastes containing toxic heavy metal ions into water sources. As such, the adsorption technique which is characterised by the adherence of the metal ions onto the surface of an adsorbent material could help to remediate polluted water. Nano-sized magnetic adsorbents with narrow size distribution have been touted to have better adsorption capacities. In this study, bare magnetite and ceria-coated magnetite particles were synthesised using co-precipitation under different stirring rates and times to obtain particles of different sizes and size distributions. Size measurements confirmed the variation of size and polydispersity index with the variation in synthesis parameters. The electron microscope images depicted large clusters formation due to agglomeration of the particle samples. Based on the results of the arsenate adsorption testing, most of the samples displayed better removal performance at temperatures of 50°C or 70°C compared to at room temperature. The removal performance was also shown to be not dependent only the average size but also the polydispersity index values.