REMOVAL OF COPPER AND LEAD FROM AQUEOUS SOLUTIONS BY PINUS BARK

Bark that was obtained from Korean Red Pine (Pinus densiflora) was used in this study to identify it as a potential adsorbent and ion exchanger of copper and lead ions in trace concentrations from aqueous solutions. Both equilibrium and non-equilibrium tests were conducted. Adsorption of copper and lead ions was pH dependent. Removal of these ions in a single component system could be well described by Langmuir and Freundlich adsorption isotherms. By treatment with nitric acid, sorption capacity of the bark was increased and the problem of initial leaching of the dark brown color could be overcome. At equilibrium, the acid treated bark showed approximately 97% of the sorption capacity of granular activated carbon. Regeneration of the spent bark with nitric acid provided almost the same capacity as fresh material.