Equilibrium and kinetic studies of anionic surfactant removal by adsorption and photocatalytic degradation using hydrotalcite-like compounds and their calcined products

Abstract

Due to the abundant use of anionic surfactants in our life and their disposal in the environment, the removal of surfactants from waste water becomes necessary. The present study focused to the synthesis and application of layered double hydroxides and their derived oxides to remove the anionic surfactant, sodium dodecyl sulphate (SDS), from aqueous solution by adsorption and photocatalytic degradation under UV irradiation. The influencing of Zn2+/Al3+ molar ratio and initial SDS concentration on the adsorption and photocatalytic degradation of SDS are studied and optimized. The obtained adsorption data were correlated with Langmuir and Freundlich isotherms models. Equilibrium studies indicated that the SDS removal obeyed Langmuir type of adsorption. Kinetic data were better described by pseudo-second-order model. The photocatalytic degradation of SDS has been found to fit the first-order kinetics according to the Langmuir–Hinshelwood model.