Removal of Zn(II) and Pb (II) ions Using Rice Husk in Food Industrial Wastewater

Abstract

T he adsorption behavior of Zn 2+ and Pb 2+ ions on rice husk was investigated using Rice Husk to remove the metals ions in dairy wastewater. The removal of mentioned heavy metal ions from aqueous solutions was studied by batch method. The main parameters that influencing Zn 2+ and Pb 2+ sorption on rice husk were: amount of adsorbent, contact time and pH value of wastewater. The influences of pH (2-9), contact time (5-70min) and adsorbent amount (0.5-3 g) have been studied. The percent adsorption of Zn 2+ and Pb 2+ ions increased with an increase in contact time and dosage of rice husk. The binding process was strongly affected by pH and the optimum pH for Zn 2+ and Pb 2+ ions were 7.0 and 9.0, respectively. The experimental data were analyzed by Langmuir isotherm. The maximum adsorption capacity of the adsorbent for Zn 2+ and Pb 2+ ions was calculated from the Langmuir isotherm and found to be 19.617 and 0.6216 mg/g, respectively. Actually the percent of removing Zn 2+ and Pb 2+ ions reached maximum to 70% and 96.8%, respectively. @JASEM Symbols: adsorbed metal on the sorbent , (mol/Kg adsorbent) weight of sorbent , (Kg) volume of metal solution , (m 3) initial metal concentration , (mol/ m 3) metal concentration at any time , (mol/ m 3) maximum sorption capacity adsorption equilibrium constant , (m 3 /mol) weight adsorbed per unit weight of adsorbent , (mol/Kg adsorbent) Freundlich constant adsorption coefficient q e-m-V-C o-C e-q m-K L-q-n-K f