Single and binary component adsorption of copper(II) and cadmium(II) from aqueous solutions using tea-industry waste

The adsorption ability of Turkish tea waste (fibrous) obtained from various tea-processing factories was investigated for the removal of Cu(II) and Cd(II) from single (non-competitive) and binary (competitive) aqueous systems. Adsorption of the investigated heavy metal ions by tea waste strongly depends on pH, contact time, initial concentration of the heavy metal ions and adsorbent dosage. The maximum adsorption capacities of Cu(II) and Cd(II) per gram tea waste were calculated as 8.64 +/- 0.51 and 11.29 +/- 10.48 mg for single and 6.65 +/- 0.31 and 2.59 +/- 10.28 mg for binary systems, respectively. The experimental data for single and binary Cu(II) and Cd(II) systems fitted the Freundlich isotherm model excellently (r(2) = 0.977-0.992). The results show that tea-processing factory waste, which has a very low economical value, may be used effectively in removal of Cu(II) and Cd(II) ions from aqueous systems for environmental cleaning purposes. (C) 2004 Elsevier B.V. All rights reserved.