Adsorption Kinetics for the Removal of Biochemical Oxygen Demand (BOD) From Dye Effluent onto Poultry Droppings Activated Carbon

Abstract

Aims/ Objectives: To prepare activated carbon from poultry droppings using H3PO4 as an activating agent and to determine the uptake of BOD from dye effluents at different contact time. Study Design: Experimental study on the effectiveness of the activated carbon at various contact time. Place and Duration of Study: Department of Chemistry Federal University of Technology Minna Niger State Nigeria, between April and November 2010. Methodology: Batch adsorption experiments were carried out for the removal of BOD from dye effluent using poultry droppings as an adsorbent. A two-step process was adopted with H3PO4 as an activating agent and the adsorption was carried out at various contact time. The rate of adsorption was carried out at various contact time. The adsorption kinetic were analysed using pseudo first-order, pseudo second-order, Natarajan and Khalaf first order and Elovich model. Results: The ash content of poultry droppings was low which is an indication of high carbon yield. It is known that as the activation burn off increases the percentage of carbon yield decreases, this is so because more volatiles are released from the char at higher burn off. The lower conductivity values obtained in the study implied that the activated carbon contain less leachable waste that are considered impurity and undesirable. Equilibrium contact time was indicated at short contact time corresponding to 30 minutes for PD/ H3PO4/10 and at long contact time or 120 minutes for PD/H3PO4/5 adsorbent. Furthermore, the pseudo second-order kinetic model was found to be the most appropriate model that best describes the adsorption kinetics. Conclusion: The findings indicated that the poultry droppings could be good raw material for the preparation of activated carbon that could be effectively used for the removal of BOD from dye effluent. The kinetics involved in the adsorption process was intraparticle diffusion control mechanism.