CeO2@PU sandwiched in chitosan and cellulose acetate layer as Cs-CeO2@PU-CA triple-layered membrane for chromium removal.

Abstract

The single or blended polymer membrane lacks a few advantages based on the durability of the membrane. The novel triple-layered sandwich membrane Cs-CeO2@PU-CA membrane is cast through the phase inversion technique for chromium removal. This approach involves an arrangement of the top layer as chitosan which acts as a protective layer, and the sandwich layer of CeO2@PU membrane which acts as source for stability, and a supportive layer of cellulose acetate is arranged accordingly. The incorporation of cerium oxide nanoparticles into the polyurethane can create pores on the surface of the membrane due to the high aspect ratio of cerium oxide. The triple-layered arrangement shows higher porosity via water contact angle, the network of pores present on the membrane which is visible through morphology, and also the intermediate sandwich layer CeO2@PU provided with better mechanical strength which would be significant for changes achieved in adsorption technique. The batch adsorption was carried out with various ppm of Cr(VI) solution. The effect of pH, contact time, initial concentration, and temperature were analyzed and optimized for determining efficiency of chromium removal. Furthermore, the suitable adsorption isotherm and kinetics of the system were also determined for better fit via Langmuir, Freundlich, Temkin, and Sips along with pseudo-first-order and pseudo-second-order. The efficiency in adsorption is due to the prominent presence of hydroxyl, carboxyl, and hydrophilic group in the prepared membrane. Thus, the resultant prepared membrane can act as a potential chromium removal substrate.