Sorption Mechanism of Cadmium from Aqueous Solution on Iron Sulphide

Abstract

The characterization and adsorption studies of Cd 2＋ on FeS were performed. Adsorption of Cd 2＋ from aqueous solutions on synthetic iron sulphide (FeS) was investigated as a function of pH (5-7) and temperature (303-323 K). It was found that the iron sulphide (FeS) had adsorptive properties comparable with those of other adsorbents reported in the literature. The sorption of Cd 2＋ was observed to increase with the increase in pH but not strongly sensitive to temperature. The adsorption data fitted both the Kurbatov and Langmuir adsorption models. In addition, ∆G values were calculated from the values of the binding constant, which showed that the cadmium adsorption process was spontaneous in nature.

Mackinawite formation from elemental iron and sulfur

“…The adsorption of Cd 2+ ions on the mackinawite surface follows an ion exchange mechanism replacing iron ions from the mackinawite surface as shown by Mustafa et al 2010. 13 Such an adsorption behavior would be expected for charged mackinawite particles. The point of zero charge of mackinawite was determined to be around pH pzc = 3 on the one hand and around pH pzc ≈ 7.5–8 on the other.…”

“…[3][4][5][6][7][8][9][10][11][12] Related to these studies are the investigations of mackinawite's pronounced capabilities to adsorb heavy and rare earth metalions what is of interest from many points of view. [13][14][15] Organic chemists have studied its reducing power towards organic nitro and chlorinated compounds that may be useful for wastewater treatment. [16][17][18] Its intrinsic physical properties like electrical conductivity and superconductivity have been studied by materials scientists.…”