Application of response surface methodology for simultaneous removal of major cations from seawater using metal oxide nanostructures

Abstract

The objectives of this study were to assess the suitability of metal oxide nanomaterials for removal of major cations Na⁺, K⁺, Ca²⁺ and Mg²⁺ from seawater. The as-synthesised nanomaterials were characterized using different techniques, such as XRD, TEM, and BET. The simultaneous removal  of Na⁺, K⁺, Ca²⁺ and Mg²⁺ ion from aqueous solutions by α-Fe₂O₃ and SiO₂/Nb₂O₅/Fe₂O₃ nanostructures was studied using batch method. The influence of different experimental parameters (such as initial metal ion concentrations, mass of adsorbent, sample pH and contact time) that affect the simultaneous removal of metal ions was studied using response surface methodology (RSM) based on small central composite design (SCCD). Under optimised conditions, the highest percentage removal was 75%, 92%, 93% and 85% for Na⁺, K⁺, Ca²⁺ and Mg²⁺, respectively.

Keywords: adsorption brine multivariable optimization nanomaterials seawater