Resistance of mass transfer, kinetic and isotherm study of ammonium removal by using a Hybrid Plug-Flow Column Reactor (HPFCR)

Abstract

Adsorption technique has been widely used for NH4 + removal from an effluent Wastewater Treatment Plant (WWTP). Still, the resistances of mass transfer, kinetics and equilibrium isotherm of NH 4 + onto Granular Activated Carbon (GAC) need to be verified. In this study, the Hybrid Plug-Flow Column Reactor (HPFCR) with a combination of sand and GAC was used to remove NH4 + from a WWTP's effluent. Mass transfer model was applied to determine the global, external and internal mass transfer. The data obtained from batch study were analysed using Langmuir and Freundlich equations; Langmuir equation fitting with the NH4 + adsorption more appropriate. The adsorption kinetics have found match well with pseudo first-order. The dependency of resistance of mass transfer on film mass transfer was slightly higher than porous diffusion, for the bed depths of 2 to 12 cm, while the dependency of resistance of mass transfer on film mass transfer was lower than porous diffusion, for the bed depths of 15 cm. The effect of varying bed depths of column on resistance of mass transfer for the adsorption of NH4 + on GAC was verified to contribute to optimizing the adsorption process for the removal of NH4 + from wastewater of containing multi-pollutants.