Hybrid Nanomaterials Based on Anionic Clays for Application to Water Dichlorophenoxyacetate and-Purification: Cases of 2,4 chlorobenzenesulfonate-4

Abstract

The elimination of the herbicide 2,4dichlorophenoxycetic acid (2,4D) and the surfactant 4chlorobenzenesulfonic acid (4CBS) from aqueous solutions by the layered double hydroxides (LDHs) through anion exchange and/or adsorption proved to be effective. The interaction of LDHs with these pollutants was investigated by a combination of spectroscopic and physico-chemical methods. Treatment of solutions containing variable concentrations of 2,4D and 4CBS led to their elimination with an uptake ratio of up to 98% for 2,4D and 95% for 4CBS. Infrared spectroscopy and X-ray diffraction indicated that this maximum of retention corresponds to an elimination of the pollutants by exchange reactions, leading to their intercalation between the LDH layers, in addition to adsorption. Thermal decomposition of LDHs samples used in water purification experiments, coupled with mass spectrometry analysis of the evolved gases, allowed to confirm the organic-inorganic hybrid character of the materials.