Adsorptive removal of Cu(II) by pistachio shell: Isotherm study, kinetic modelling and scale-up designing — continuous mode

Abstract

Abstract Cu(II) ions discharged from various industrial effluents, cause water pollution. Recently adsorption using various low-cost green adsorbents in continuous mode was practised for the mitigation of water pollution. Adsorption of Cu(II) using pistachio shell in continuous lab scale adsorption column was done in this study. Physical characterization of pistachio shell was done by Point of zero charge (pH pzc ) estimation, Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and Brunauer–Emmett–Teller (BET) analysis. Various experiments were done to know the behaviour of adsorption breakthrough against different operating conditions. Langmuir isotherm and Freundlich isotherm were fitted with adsorption equilibrium data, among which fitting of Langmuir isotherm is better ( K L = 0 .4423L/mg, R 2 = 0 .9986). Seven mathematical models were tried on the experimental result, among them Thomas model performed well for the selected operating range ( k T H = 0 . 636 mL/(mg. Min), q 0 = 12 . 58 mg/g, R 2 = 0 .9431) and utilized for plant designing purpose. Regeneration of pistachio shell with 0.4(N) HCl solution suggests that pistachio shell was able to remove Cu(II) ions multiple time. Experiments using industrial wastewater were also reported. This study signifies that pistachio shell may be utilized for Cu(II) ion removal from industrial effluent.