The Zinc Adsorption Study by Using Orhaneli Fly Ash, Bentonite, and Molasses in Wastewater

Abstract

Fly ash is currently being generated at a rate of million tons every year and represents an important waste problem. Bentonite and molasses are used in a wide range of applications. The samples of Orhaneli fly ash were analyzed by X-ray fluorescence, Fourier transform infrared spectroscopy, and scanning electron microscope. Depending on the results of the analysis, morphology and chemical compositions of Orhaneli fly ash were investigated in detail. Orhaneli fly ash, bentonite (0 and 1 % in terms of fly ash, w/w), and molasses (0-0.75 mL) were pelletized under 30 MPa of pressure for zinc adsorption in wastewater. As a result, it was seen that the usage of Orhaneli fly ash was proper for zinc (Zn2+) adsorption and an optimum adsorption yield with 90 % was found at a compound with Orhaneli fly ash (10 g), bentonite (0 %), and molasses (0.25 mL) at 2.5 h of reaction time, pH5, 20 C of reaction temperature, and 300 rpm of stirring rate. Sorption isotherm and sorption kinetics for Zn2+ on fly ash (with bentonite and molasses) can be explained by Freundlich isotherm and pseudo-second-order kinetic models. Based on the experimental data, it was seen that Orhaneli fly ash and molasses waste could be evaluated for Zn2+ adsorption from wastewater, environmentally.