The mechanisms and kinetics of phosphate adsorption onto iron-coated waste mussel shell observed from hydrodynamic column

Abstract

he excessive amount of phosphate in domestic wastewater treatment plant effluent must be removed to protect the natural environment of healthy aquatic ecosystem. Though a number of adsorption techniques with various low-cost adsorbent have been proposed, it is still ambiguous how the iron-coated waste mussel shell properties affect the adsorption kinetics of phosphate removal from an effluent. The analysis of experimental data was carried out using the bed depth service time, Thomas, and modified mass transfer factor models to study the adsorption kinetics of phosphate deposited on the surface of iron-coated waste mussel shell observed from hybrid plug flow column reactor. The overall adsorption kinetics of phosphate investigated using the Ka and No values referred to the bed depth service time models and the KT and qo values referred to the Thomas models are still acceptable. Detailed analysis of the mechanisms of film mass transfer and porous diffusion using the modified mass transfer factor models is able to determine the kinetic rate of phosphate adsorption. Mass transfer resistance for the adsorption of phosphate onto iron-coated waste mussel shell from domestic wastewater treatment plant effluent is dependent on porous diffusion ultimately contributing to develop advanced iron-coated waste mussel shell adsorbent for enhancing the performance of hybrid plug flow column reactor in future.