engleski

Eggshell as a new biosorbent for the removal of the pharmaceuticals from aqueous solutions

The suitability of chicken eggshell as a novel sorbent for removal of pharmaceuticals (dexamethasone (DEX), febantel (FEB), praziquantel (PRAZ), procaine (PROC) and tylosin (TYL)) from water was investigated. Batch sorption experiments were performed to detect the effect of initial concentration of pharmaceuticals, contact time and temperature on the eggshell sorption capacity. The eggshell sample was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy combined with energy dispersive spectroscopy, and with particle and pore size distribution analyses. Equilibrium data were analysed using Freundlich and Dubinin–Radushkevich isotherms. The thermodynamic parameters (G°, H° and S°) were calculated in order to predict the sorption nature. The results indicated spontaneous and exothermic sorption process of PROC ; spontaneous and endothermic for DEX, FEB, TYL and non-spontaneous nature and exothermic for PRAZ. According to the experimental results, chicken eggshell as mesoporous sorbent can be successfully used as an alternative and low-cost biosorbent. The kinetic experimental data were fitted by Lagergren’s pseudo-first order and Ho’s pseudo- second-order model. Kinetic parameters, rate constants, equilibrium sorption capacities and correlation coefficients were estimated and discussed for both kinetic models. The pseudo- second-order model was suitable for prediction of sorption capacities. The mechanism of the sorption process is determined by the Weber– Morris intraparticle diffusion model and Boyd model. The sorption rate of investigated pharmaceuticals to chicken eggshells is influenced by both diffusion types: intraparticle and film diffusion.

eggshell ; pharmaceuticals ; sorption ; isotherms ; kinetic models

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