Effects of iron oxide on antimonyV adsorption in

Authors: Yuxian Shangguan Xiaopeng Qin Long Zhao Linquan Wang Hong Hou

Publish Date: 2015/08/19

Volume: 16, Issue: 2, Pages: 509-517

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Abstract

Antimony Sb contamination in the environment is a worldwide concern To address such contamination issues we studied the adsorption of Sb in four different types of soils We investigated the main chemical and physical factors that influenced the adsorption of Sb and distinguished between the different adsorption abilities of naturally occurring crystalline and amorphous iron Fe compounds in these soilsAdsorption of Sb in ferrosol primosol isohumosol and sandy soil was studied using batch experiments Transmission electron microscopy and Xray photoelectron spectroscopy were used to examine the character and location of Sb adsorbed on individual particles in these soils without affecting its geochemical environment In addition the crystalline and amorphous Fe compounds in these soils were separated and analyzed using Xray diffraction The relationship between these Fe compounds and Sb adsorption was also exploredThe sorption capacities of the four soils increased on addition of Sb in solution reaching values of 108 433 545 and 119 g kg−1 for ferrosol primosol isohumosol and sandy soil respectively The adsorption of Sb in ferrosol was much higher than for other soils because of its higher Fe oxide content In fact the Sb content adsorbed on ferrosol showed a good exponential relationship with its Fe content The Xray photoelectron spectroscopy results indicated that the Fe2p and O1s binding energies decreased after the adsorption of Sb in the ferrosol This suggests that an electron transfer occurred between Sb and Fe through an oxidationreduction reaction after Sb adsorption in the ferrosolThe adsorption abilities of Sb in the four soils were in the order of ferrosol isohumosol primosol sandy soil The amounts of Sb adsorbed by these soils were significantly positively correlated with their Fe contents Sb = −378 + 288 × Fe P  001 but were negatively correlated with their sand contents Sb = 1230 − 012 × Sand P  001 The Xray diffraction analysis results showed that crystalline Fe compounds have a higher capacity for Sb adsorption than amorphous Fe compounds

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