Abstract
The aim of this work was to study of the kinetic of Pb(II) sorption, in high lead concentration aqueous solution, by the natural hydroxyapatite (HA) and to verify whether there is a different behavior between natural and synthetic HA under different lead concentrations. Batch experiments were carried out using solutions with high lead concentration, with the objective to evaluate the effect of contact time, HA dosage and initial metal concentration on lead removal. Kinetic data were analyzed by pseudo-first and pseudo-second order models. The sorption data was then correlated with the Langmuir and Freundlich isotherm models. The PZC obtained was slightly different than those reported by other authors, who evaluated the process under low concentrations and synthetic HA as adsorbent. It was possible to identify the optimum relation between Pb(II) concentrations and mass of HA for efficiency of approximately 100% at optimum contact time. Although the results show a certain instability during the removal of lead when the concentration is much higher, the process can be considered effective. Liquid samples were analyzed by atomic absorption spectroscopy and solid samples were by X-ray diffraction and Fourier transform infrared spectroscopy.
Highlights
Heavy metals are not biodegradable and tend to accumulate in living organisms, causing various diseases and disorders
The present study focuses on the removal of Pb(II) from aqueous solution by hydroxyapatite obtained from bovine bone
According to results obtained for the study of the adsorption balance and the kinetics of the Pb(II) on HA, obtained from bovine bone, we can consider that natural HA exhibits a similar behavior to the synthetic HA reported in the literature, where a high percentage of removal is observed in the first few minutes and its speed is reduced until a point of saturation
Summary
Heavy metals are not biodegradable and tend to accumulate in living organisms, causing various diseases and disorders. Lead ion-Pb(II) has been classified as a hazardous heavy metal with high priority in the context of environmental risk[1]. Various methods have been developed to eliminate or reduce heavy metals from wastewaters. In many cases, these methods are very expensive and non-viable, including chemical precipitation, membrane filtration, ion exchange, carbon adsorption and co-precipitation/ adsorption[5]. An adsorption processes involve high efficiency materials for heavy metals removal from aqueous solutions, easy handling, availability of different raw materials and low cost[6]. Different raw materials[10,11] have been used as adsorbents for the removal of heavy metals from aqueous media and soil contaminated. The authors reported the optimum parameters to obtain approximately 90% of metal removal within the first 15 min
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
