The adsorption of Cr(Vi) from synthetic solution onto mussel shell incorporated polyethersulfone flat sheet membranes: application of the mass transfer factor models

Abstract

The high amount of hexavalent chromium in contaminated water must be removed because it can have serious implications on human health. Prolonged exposure to hexavalent chromium can lead to kidney damage and lung cancer in humans. The adsorption of hexavalent chromium from synthetic solution onto mussel shell (MS)-incorporated polyethersulfone (PES) flat sheet adsorptive membranes applied to a flat sheet adsorptive membrane crossflow (FSAMC) treatment system was studied in this work. The MS-PES flat sheet membranes were prepared by varying the mass ratio of MS-PES from 0 to 0.5, 1.0, and 1.5. The instrumental analysis was used to determine the physicochemical properties of the MS-PES membranes. The chemical composition of MS was analyzed using an energy-dispersive X-ray fluorescence spectrometer. The Brunauer-Emmett-Teller surface area of MS was determined by the multiple-point method using a surface analyzer. The surface and cross-sectional features of MS-PES membranes were observed under a scanning electron microscope. The analysis of water contact angle and porosity of MS-PES membranes was conducted using a contact angle goniometer and the gravitational method, respectively. The maximum adsorption capacity of 6.45 mg g(-1) was obtained for the adsorption of hexavalent chromium onto MS-PES (1.0) membrane from synthetic solution. The analysis of experimental data was performed using the mass transfer factor models to determine the resistance of mass transfer (RMT) for the adsorption of hexavalent chromium from synthetic solution onto MS-PES membranes, which is dependent on either film mass transfer or porous diffusion. This work determined that the RMT for the adsorption of hexavalent chromium from synthetic solution onto MS-PES membranes applied to the FSAMC treatment system is dependent on film mass transfer. The knowledge of the RMT for transporting hexavalent chromium onto MS-PES membranes is considered expedient for designing an advanced water treatment system to release hexavalent chromium-free treated water.