ADSORPTIVE REMOVAL OF LEAD(II) USING ACTIVATED CARBONACEOUS ADSORBENT OBTAINED FROM WALLNUT SHELL(Juglans regia)

Abstract

Presence of heavy metal ions in excess than permissible limit in aquatic environment can cause serious problems to human being and aquatic life. Adsorption is by far the most effective method for the removal of trace amounts of toxic heavy metals from wastewater. The main aim of this thesis work is to prepare a low-cost, effective, and highly efficient adsorbent from the walnut shell by chemical modification for the removal of Pb(II) ions from an aqueous solution. Charred walnut shell (CWS) and xanthated walnut shell (XWS) as adsorbents have been prepared. FTIR, XRD, and SEM characterization are used for the characterization of adsorbents. Batch experiments are performed for analysis. The effect of pH, Pb(II) concentration, and contact time have been investigated using both CWS and XWS adsorbents. The optimum working pH of 4 and optimum time of 150 min are determined for both the adsorbents. Equilibrium sorption data are best fitted for the Langmuir isotherm model and the maximum adsorption capacity of CWS and XWS are found to be 61 mg/g and 109.9 mg/g, respectively. Kinetic modeling studies revealed that the experimental data best fit to pseudo-second-order kinetic model. These results demonstrate that XWS may be an attractive alternative bio-adsorbent for the removal of Pb(II) from an aqueous solution