Comparative study of differently treated animal bones for Co super(2) super(+) removal

• Published in: Journal of hazardous materials 2009-05, Vol.164 (1), p.279-287
• Main Authors: Dimovic, S, Smiciklas, I, Plecas, I, Antonovic, D, Mitric, M
• Format: Article
• Language: English
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2008.08.013

The objective of the present study was the evaluation of differently treated bovine bones for Co super(2) super(+) removal from aqueous media. Powdered bones (B), as well as samples prepared by H sub(2)O sub(2) oxidation (BH sub(2)O sub(2)) and annealing at 400-1000 super(o)C (B400-B1000), were tested as sorbent materials. A combination of XRD, FTIR spectroscopies, DTA/TGA analyses, specific surface area (S sub(p)) and point of zero charge (pH sub(P) sub(Z) sub(C)) measurements was utilized for physicochemical characterization of sorbents. Sorption of Co super(2) super(+) was studied in batch conditions as a function of pH, contact time and Co super(2) super(+) concentration. Initial pH values in the range 4-8 were found optimal for sorption experiments. Equilibrium time of 24h was required in all investigated systems. The maximum sorption capacities differ significantly from 0.078 to 0.495mmol/g, whereas the affinity towards Co super(2) super(+) decreased in the order: B400>BH sub(2)O sub(2)>B600>B>B800>B1000. The pseudo-second-order model and Langmuir theoretical equation were used for fitting the kinetic and equilibrium data, respectively. Ion-exchange with Ca super(2) super(+) and specific cation sorption were identified as main removal mechanisms. The amounts of Co super(2) super(+) desorbed from loaded bone sorbents increased with the decrease of pH as well as with the increase of Ca super(2) super(+) concentration. Heating at 400 super(o)C was found to be an optimal treatment for the production of the Co super(2) super(+) removal agent.