Nickel adsorption on the modified pine tree materials.
Removal of nickel ions from aqueous solutions containing 1-100 mg l(-1), using pine tree (Pinus nigra) materials modified with HCl, was investigated on a laboratory scale. For this purpose, two natural adsorbents such as the modified pine bark (MPB) and the modified pine cone (MPC) materials with HCl solution were studied. At first, the required concentration level of the HCl solution for the modification was observed, and then this was followed by the determinations of optimum levels of adsorbent amount, stirring rate, contact time and pH values. Various adsorption isotherms were also obtained by using different concentrations of the heavy metal cations tested in the experiment. As a result, the maximum removal efficiency levels obtained were as follows; 97% for the modified pine bark at pH 8 and 80% for the modified pine cone at pH 8.