Batch zinc removal from aqueous solution using dried animal bones

The effectiveness of animal bones (AB) to adsorb zinc from aqueous solution was studied. Batch kinetics and isotherm studies were carried out to investigate the effect of contact time, initial concentration of the adsorbate, particle size, temperature, pH, and the addition of salt (NaCl) on this adsorption process. It was noted that an increase in the zinc concentration, temperature, and initial pH of the metal solution resulted in an increase in the metal uptake per unit weight of the sorbent. The decrease in the particle size of the sorbent resulted in an increase in the metal uptake per unit weight of the sorbent. The concentration of salt in the metal solution showed significant influence on the zinc ion sorption by the sorbent. Freundlich and Langmuir isotherm models were found to be applicable for the experimental data of Zn²⁺ sorption by AB. Desorption of metals from pre-loaded AB with zinc ions was carried out with different acid eluants and it was found that H₂SO₄ is the most effective desorbent. (C) 2000 Elsevier Science B.V. All rights reserved.