Design and Implementation\nof a Heterogeneous Magnetic\nQuaternary Composite for Efficient Arsenic(V) Removal in Polluted\nWater

This work highlights a potential\nquaternary composite\nadsorbent\n(CT: <b>γ-</b>Fe<sub>2</sub>O<sub>3</sub>–TiO<sub>2</sub>-GO-zeolite 5A) to remove As(V) from contaminated water. The\nCT was characterized by various analytical techniques before and after\nthe adsorption experiments. Contact time, pH, and adsorbent dose were\nevaluated. The results indicated a removal greater than 94% in a contact\ntime of 3 h at a pH of 6.5. The data on adsorption kinetics agree\nwith the pseudo-second-order model; while the adsorption isotherms\ncoincide with Sips model, which suggests that the adsorption of As\nin the CT composite is carried out through chemisorption. In addition,\nScanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy\n(EDS) revealed the deformation of the CT structure. X-ray diffraction\n(XRD) showed the reduction of zeolite 5A crystallite size from 76.1\nto 28.3 nm, of γ-Fe<sub>2</sub>O<sub>3</sub> from 15.3 to 7.7\nnm, while that of anatase remained unchanged. The magnetic analysis\nconfirmed that the composite has response to magnetic handling still\nafter adsorption, as necessary for its separation. Based on the X-ray\nphotoelectron spectroscopy (XPS) results, γ-Fe<sub>2</sub>O<sub>3</sub> and Z5A are proposed as compounds of major participation\nin As adsorption, through weak electrostatic interaction and complex\nformation, respectively. In addition, GO contributes hydroxyl groups\nreducing the repulsion by the negative As species. Thus, this composite\npresents remarkable characteristics as an alternative for remediation\nof water contaminated with As.