Modification of clinoptilolite with dialkylphosphinic acid for the selective removal of cobalt (II) and nickel (II) from hydrometallurgical effluent

Abstract

AbstractThis study describes the selective removal of cobalt (II) and nickel (II) from hydrometallurgical effluent using modified clinoptilolite. X‐ray fluorescence (XRF), x‐ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis were used to characterize the natural and modified clinoptilolites with dialkylphosphinic acid. In a batch experiment, the influence of different variables such as initial concentration, pH, particle size, clinoptilolites dosage, temperature, and contact time was evaluated. Higher removal efficiency was obtained at initial concentration of 600 mg/L, pH 6, particles size of 1000‐1400 μm, dosage of 10 g/100 mL, a temperature of 25°C, and contact time of 300 minutes. The experimental data fit satisfactorily to the pseudo‐second order kinetic and to the Langmuir isotherm model. Thermodynamic parameters like Gibb's free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo) were also evaluated. The results revealed that modified clinoptilolite with dialkylphosphinic acid could be successfully employed for the selective removal of cobalt (II) and nickel (II) from hydrometallurgical effluent.