Fabrication of Fe3O4 nanoparticles coated by extracted shrimp peels chitosan as sustainable adsorbents for removal of chromium contaminates from wastewater: The design of experiment

Water is the most critical substance on Earth; any contamination of water may cause harmful consequences for the entire living creatures. Today, removal of various pollutants from the water is one of the most critical concerns; in this regard, application of the minimum amount of chemicals or use of the natural structures and bio-synthetic methods for pollutant elimination are of critical importance. In this paper, Fe3O4 nanoparticles were biosynthesized by co-precipitation method at the presence of the shrimp-extracted chitosan and tripolyphosphate. The pure and chitosan-coated nanoparticles were characterized by scanning electron microscope SEM, TEM, EDX, FTIR, XRD, XPS, VSM and TGA methods. The application of the chitosan-coated Fe3O4 nano-particles was then evaluated in the extraction and green removal of chromium (VI) from water samples. The effective parameters such as pH, contact time, adsorbent dosage, and agitation speed were optimized by design of experiment method and investigated by response surface methodology (RSM). Based on the results, 75-88% of Cr (VI) could be removed from the actual samples indicating the high chromate removal efficiency of the synthetic adsorbents.