Preparation of a Novel Composite Using Chitosan, Laterite and Iron Oxide Nanoparticles and Its Efficacy in Removing Methylene Blue Dye and Arsenic from Water

Bio-materials are abundant and are finding new avenues of applications. In this research, chitosan, iron oxide nano-particles and laterite clay composite was prepared using sodium-polyphosphate as the cross linker. The reasons of using chitosan are that it is easily available in our country, often used as adsorbents and is biodegradable. Iron oxide nano particles were used to recover the composite. Furthermore, they are often used for the adsorption of arsenic. Laterites are common in Bangladesh and is cheap. Hence, the composite compositions were chosen with a view to preparing them in large scale cost effectively. Composites with different compositions of the three ingredients were prepared and their pore volume and methylene blue (MB) adsorption capacity was compared and the study shows that 1:1:1 composition provides the best suitable adsorption. Removal of MB using this composite shows that with the increase of pH the removal increases and showed maximum adsorption capacity (Q) of 13 mg/g and for arsenic the pH dependency follows the opposite trend of MB and Q value is 0.291 mg/g. Both cases shows that the adsorption is following Langmuir Isotherm model and chemi-sorption is the rate determining step. Studying the nature of the composite tells us that it can be a good anti-microbial agent as well. Finally this non-toxic composite harbors potential in the fields of application of different branches of environmental and pharmaceutical science.