Synthesis of Fly Ash and Bentonite-Supported Zero-Valent Iron and Its Application for Removal of Toxic Cationic Dyes from Aqueous Solutions Article uri icon

abstract

  • A new adsorbing material for crystal violet (CV) and methylene blue (MB) dye removal, fly ash and bentonite-supported microscale zero-valent iron (FB-mZVI), was synthesized by using iron-ore tailings (IOT) as the iron source. Palm kernel shells (PKSs) were used to reduce the iron oxide of the IOT to Feo. A statistical orthogonal method was used to evaluate the factors determining the adsorbent synthesis. It was found that the important factors were the mass ratio of the fly ash, bentonite, IOT, and PKSs as well as the synthesis time, temperature, and heating rate. Optimum mass ratio of the fly ash, bentonite, PKSs, and IOT was found to be 2:2:1:1, and optimum synthesis temperature, time, and heating rate were found to be 800°C, 10 min, and 10°C/min, respectively. An FB-mZVI adsorbent was used to remove the CV and MB from aqueous solutions. Removal efficiency for CV was much higher than that for MB. UV, XRD, and FTIR analyses revealed that the adsorption mechanisms for removal of CV were different from those for MB. Adsorption process was well described by the pseudo-second-order kinetic model, and Langmuir isotherm model better represented the adsorption isotherm data. © Copyright 2017, Mary Ann Liebert, Inc. 2017.

publication date

  • 2017-01-01