Organo-nanobentonite and organo-nanokaoline for effective removal of Pb(II) ions from battery effluent: characterization, isotherm, kinetic studies

Abstract

a b s t r a c tLead is considered as one of the deadliest heavy metals which causes severe impact on the environment. In the present work,the experimental study was carried out by using eco-friendly nano-adsorbent material ONK (organo-nanokaoline) and ONB (organo-nanobentonite) for the effective removal of Pb(II) ions from battery synthetic effluent. The organically modified adsorbents were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX), thermogravimetric analysis (TGA). Operating parameters such as pH, adsorbent dosage and contact time were experimentally optimized for the maximum removal of ions. The optimum conditions were found to be at pH of 4, a dosage of 4 g/L, 30 min equilibrium time with 400 mg/L initial concentration for ONK. The adsorption data was fitted with isotherm models such as Langmuir and Freundlich. The monolayer adsorption capacity of ONK and ONB for Pb(II) ions was reported to be about 47 mg/g (ONK), 32 mg/g (ONB), respectively. Adsorption kinetics and mechanism were analyzed using pseudo-first order, pseudo-second order, intra particle diffusion model, and Boyd model. The pseudo second order kinetic model provided the best fit for absorption of ions.