Characterization of Fe(III) Adsorption onto Zeolite and Bentonite.

Tomáš Bakalár,Anna Girová,Zuzana Hajduová,Henrieta Pavolová,Mária Kaňuchová,Rudolf Hromada

doi:10.3390/ijerph17165718

Abstract

In this study, the adsorption of Fe(III) from aqueous solution on zeolite and bentonite was investigated by combining batch adsorption technique, Atomic adsorption spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy analyses. Although iron is commonly found in water and is an essential bioelement, many industrial processes require efficient removal of iron from water. Two types of zeolite and two types of bentonite were used. The results showed that the maximum adsorption capacities for removal of Fe (III) by Zeolite Micro 20, Zeolite Micro 50, blue bentonite, and brown bentonite were 10.19, 9.73, 11.64, and 16.65 mg.g−1, respectively. Based on the X-ray photoelectron spectroscopy (XPS) and X-ray fluorescence (XRF) analyses of the raw samples and the solid residues after sorption at low and high initial Fe concentrations, the Fe content is different in the surface layer and in the bulk of the material. In the case of lower initial Fe concentration (200 mg.dm−3), more than 95% of Fe is adsorbed in the surface layer. In the case of higher initial Fe concentration (4000 mg.dm−3), only about 45% and 61% of Fe is adsorbent in the surface layer of zeolite and bentonite, respectively; the rest is adsorbed in deeper layers.

Highlights

Iron [Fe(III)] is commonly found in almost all types of water, including surface and drinking water, but in some types of water, e.g., water used in heating systems and water-tube boilers, it is unfavorable.Iron is a biogenic element
Bentonites, and other natural material are widely used for removal of iron and other heavy metals and inorganic pollutants
In the case of lower initial Fe concentration, more than 95% of Fe is adsorbed in the surface layer

Summary

Introduction

Iron [Fe(III)] is commonly found in almost all types of water, including surface and drinking water, but in some types of water, e.g., water used in heating systems and water-tube boilers, it is unfavorable.Iron is a biogenic element. Iron [Fe(III)] is commonly found in almost all types of water, including surface and drinking water, but in some types of water, e.g., water used in heating systems and water-tube boilers, it is unfavorable. Its removal has been widely studied due to precipitation in water distribution systems [1,2]. The most advantageous material is natural material, e.g., zeolite, bentonite, etc. Bentonites, and other natural material are widely used for removal of iron and other heavy metals and inorganic pollutants. Zeolites are often used in water treatment for drinking water purposes. Both zeolites and bentonites are used in wastewater treatment [8,9,10]

Results

Discussion

Conclusion