Abstract

Dyes found in industrial effluents are one of the most significant hazardous (toxic) materials, therefore its removal before discharge of effluents is essential. The main purpose of this study is to investigate the removal of Remazol Black B (RBB) from its aqueous solution using synthesized P-γ-Fe2O3 nanoparticles. The P-γ-Fe2O3 nanoparticles were prepared using the surfactant-free electrochemical technique, and characterized for its spectral properties. The influence of different process parameters such as pH (3-12), dosage of P-γ-Fe2O3 nanoparticles (0.1-5 g L-1), initial concentration of RBB (50-600 mg L-1), contact time (10-150 min) and solution temperature (298 and 303 K) was studied using the batch adsorption technique. The kinetic, isotherm and thermodynamic parameters were also evaluated. The adsorption efficiency was increased by decreasing the pH of the solution, the dosage of P-γ-Fe2O3 nanoparticles, the initial concentration of RBB and the solution temperature. Maximum RBB removal efficiency of 99.74 was attained at the optimum pH of 3, P-γ-Fe2O3 nanoparticles dosage of 0.1 g L-1, initial concentration of 100 mg L-1, contact time of 10 min and solution temperature of 298 K. The adsorption of RBB on P-γ-Fe2O3 nanoparticles was found to fit best into the pseudo-second-order kinetic model than the pseudo-first-order, which indicates a chemical adsorption process. The adsorption process was best described by the Langmuir adsorption isotherm model with maximum adsorption capacity, qm of 192.3 mg g-1. The adsorption of RBB on P-γ-Fe2O3 was found to be non-spontaneous and endothermic in nature. The results obtained revealed that the synthesized P-γ-Fe2O3 nanoparticles could be applied effectively for the removal of RBB from its aqueous solution. © 2019 Desalination Publications. All rights reserved.