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

• Published in: Journal of hazardous materials Vol. 164; no. 1; pp. 279 - 287
• Main Authors: Dimović, S, Smiciklas, I, Plećas, I, Antonović, D, Mitrić, M
• Format: Journal Article
• Language: English
• Published: Netherlands 15-05-2009
• Subjects: Adsorption; Animals; Bone and Bones - chemistry; Cattle; Cobalt - chemistry; Cobalt - isolation & purification; Hydrogen Peroxide - chemistry; Hydrogen-Ion Concentration; Kinetics; Temperature; Waste Disposal, Fluid - methods; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; Water Purification - methods
• 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(2+) removal from aqueous media. Powdered bones (B), as well as samples prepared by H(2)O(2) oxidation (BH(2)O(2)) and annealing at 400-1000 degrees C (B400-B1000), were tested as sorbent materials. A combination of XRD, FTIR spectroscopies, DTA/TGA analyses, specific surface area (S(p)) and point of zero charge (pH(PZC)) measurements was utilized for physicochemical characterization of sorbents. Sorption of Co(2+) was studied in batch conditions as a function of pH, contact time and Co(2+) 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(2+) decreased in the order: B400>BH(2)O(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(2+) and specific cation sorption were identified as main removal mechanisms. The amounts of Co(2+) desorbed from loaded bone sorbents increased with the decrease of pH as well as with the increase of Ca(2+) concentration. Heating at 400 degrees C was found to be an optimal treatment for the production of the Co(2+) removal agent.