Adsorption of arsenazo (III) by phosphorus-containing polymer sorbent

Abstract

Phosphorus-containing polymer sorbent was employed for removal hazardous Arsenazo (III) dye from water. The adsorption characteristics were determined by the study at different parameters such as effect of solution pH, effect of initial dye concentration, sorbent dose, phase contact time, and temperature. The equilibrium data were analyzed on the basis of various adsorption isotherm models, namely Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich. The highest monolayer adsorption capacity has been obtained (24.75 mg g^-1) at 55°C. Different thermodynamic parameters such as free energy, enthalpy, and entropy have been calculated and it was concluded that when temperature rises, adsorption increases, indicating the endothermic nature of the process. Kinetic parameters were derived by pseudo-first-order, pseudo-second-order and intraparticle kinetic models. Scanning Electron Microscopy and Fourier Transform Infrared spectroscopy were used to characterize the sorbent and also to validate the adsorption mechanism.