Abstract

The adsorption of Cu²⁺ and Zn²⁺ ions on bamboo root biomass from an aqueous solution was studied. Some parameters that determine metal uptake including contact time, adsorbent dose and initial concentration of the metal ions were evaluated. The optimum contact time to attain equilibrium is of the order of 15 to 20 min for both metal ions. The kinetic studies showed that the sorption rates could be described by a pseudo-second order process. Rate constants were determined as 9.13 x 10^-2 and 6.30 x 10^-2 g mg^-1 min^-1 for Cu²⁺ and Zn²⁺ ions, respectively. The equilibrium sorption capacity of Cu²⁺ and Zn²⁺ ions were determined from the Langmuir equation as 28.57 and 50.00 mg g^-1, respectively. The results from this study showed that acid treated bamboo root could be a good adsorbent for the removal of Cu²⁺ and Zn²⁺ ions from industrial effluents. The sorption process is adjudged endothermic as the apparent free energy change (∆G^o_ad) values were found to be 4.14 and 5.22 kJ mol^-1 for Cu²⁺ and Zn²⁺ ions, respectively.

Key words: Industrial effluents, adsorption, adsorbent, biomass, endothermic