Synthesis and physicochemical characterization of ZnMgNiAl-CO3-layered double hydroxide and evaluation of its sodium dodecylbenzenesulfonate removal efficiency

Abstract

In this study, the adsorption of anionic surfactant by uncalcined ZnMgNiAl-CO 3 was examined using sodium dodecylbenzenesulfonate (SDBS) as a model compound in an aqueous solution. The synthesized adsorbent (ZnMgNiAl-CO 3 ) was characterized by FTIR, X-ray diffraction, and BET. The capacity of ZnMgNiAl-CO 3 to adsorb surfactant was evaluated at different contact times, pH values, mass effect, and initial surfactant concentrations. According to the obtained results, the adsorption processes could be described by a pseudosecond-order kinetic model. The adsorption isotherm was well fitted by the Sips model. Maximum adsorption capacity for SDBS on ZnMgNiAl-CO 3 was found to be 191.7 mg/g which was in accordance with the experimental value. Thermodynamic parameters were estimated as well, and their values indicated that the adsorption process was spontaneous and endothermic. The values of ΔH˚and ΔS˚of the adsorption process were 7.9 and 0.102 kJ/mol, respectively. The low value of ΔH˚(<40 kJ/mol) indicated that adsorption process occurs mainly through a physical means.

Synthesis and physicochemical characterization of new calcined layered double hydroxide Mg Zn Co Al-CO3; classical modeling and statistical physics of nitrate adsorption

“…When the dosage of the adsorbent is high, a very rapid, but superficial, adsorption occurs on the surface of the adsorbent, resulting in a low adsorption capacity. Thus, with weak doses of the adsorbent, the quantity of the nitrate adsorbed per unit mass of the MgZnCoAl-CO 3 increases, causing an increase in the Qe value[69] [70].…”