Adsorption of Lanthanum (III)-Iron (III)-Doped Waste Coal Fly Ash Composite Adsorbent for Reactive Dyes from Aqueous Solution

Abstract

A composite adsorbent La/Fe/FA for reactive turquoise blue KN-G (RTB KN-G) and reactive brilliant blue KN-R (RBB KN-R) removal from aqueous solution was prepared by loading lanthanum (III) and iron (III) onto waste coal fly ash (FA). The adsorption behavior of RTB KN-G and RBB KN-R on La/Fe/FA was investigated systematically. The results show that the initial dye concentration, contact time, pH value and temperature are all the important factors influencing the adsorption. The adsorption of La/Fe/FA for two reactive dyes at different temperatures were very fast and can establish sorption equilibrium at 30min, and agreed well with pseudo-second-order kinetics. The equilibrium adsorption data could be described by the Langmuir isotherm equation well, and obtained maximum adsorption capacities at 25°C were 56.28 mg/g for RTB KN-G and 116.82mg/g for RBB KN-R, respectively. The rise of temperature was not conducive to adsorption. The results show that the La/Fe/FA adsorbent displays high effective adsorption for reactive dyes and will have potential as a promising application in the field of water pollution control and recycling utilization of resources.