Optimization of Chromium(VI) and Copper(II) Adsorption on Chemically Treated Sawdust Using Response Surface Methodology

Abstract

Chromium(VI) and copper(II) are the most significant industrial effluent whose direct discharge into nearby waterways creates water pollution. Wastewater containing Cr(VI) is released from several industrial activities like electroplating, tanning, plastic surfaces coating and it causes cancer in digestive tract and lungs. Copper(II) is found in industrial effluents including acid mine drainage and galvanizing plants and higher doses leads to anemia, kidney and liver damage. Sawdust is a waste by-product of the timber industry that can be utilized as bio adsorbent for the removal of heavy metals. In the present study, the potential of sawdust for the removal of Cr(VI) and Cu(II) from an aqueous solution through column based adsorption process has been investigated. Response surface methodology is applied for optimization of variables e.g. metal concentration, pH and column bed height. The optimum conditions for maximum removal of chromium (89.74 %) and copper (93.17 %) from aqueous medium are: column bed height (20 cm, 20 cm), initial concentration (30 mg/L, 10 mg/L) and pH (2, 4), respectively. The results indicated that sawdust is a promising, effective and an inexpensive material for the removal of Cr(VI) and Cu(II) from industrial wastewater.