Heavy Metal Removal from Aqueous Solutions Using Fly-Ash Derived Zeolite NaP1
Archibald Frank Ankrah, Begüm Tokay, Colin E. Snape
Abstract
Abstract Fly-ash derived zeolites have recently -received great attention as cheaper adsorbents to remove heavy metals from water since they can be synthesized from a waste product. In this study, we evaluated the single- and multi-cation adsorption efficiencies of fly-ash derived NaP1 for the removal of zinc (Zn), copper (Cu) and lead (Pb). We also determined precipitation and leaching from NaP1 during the adsorption. Results showed that the uptake capacities for Zn (34 mg/g) and Pb (192 mg/g) were higher than other fly-ash derived NaP1 and adsorbents such as clinoptilolite and activated carbon. The Cu uptake was estimated ~ 14.6 mg/g. Pb 2+ > Cu 2+ > Zn 2+ is the order for the metal cation selectivity of NaP1. Langmuir adsorption isotherm and pseudo-second order kinetic model fitted best for all elements. The metal uptake occurred in 15 min. Diffusion of hydrated metals through microporous channels is the rate-determining step.