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Quantitative and spectroscopic investigations of the co‐sorption of myo ‐inositol hexakisphosphate and cadmium( II ) on to haematite
Author(s) -
Wan B.,
Yan Y. P.,
Zhu M. Q.,
Wang X. M.,
Liu F.,
Tan W. F.,
Feng X. H.
Publication year - 2017
Publication title -
european journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 1351-0754
DOI - 10.1111/ejss.12424
Subject(s) - chemistry , sorption , ternary operation , aqueous solution , phosphate , cadmium , inorganic chemistry , fourier transform infrared spectroscopy , nuclear chemistry , adsorption , chemical engineering , organic chemistry , computer science , engineering , programming language
Summary The interactions between phosphates, both inorganic and organic ones, and heavy metals on mineral surfaces affect their environmental fate and transport. In this research, we investigated the co‐sorption of myo ‐inositol hexakisphosphate ( IHP ) and cadmium ( C d( II )) on to haematite at various pHs in batch experiments, zeta ( ζ ) potential measurement and in situ attenuated total reflectance F ourier transform infrared ( ATR‐FTIR ) spectroscopy. In the haematite– IHP binary system, IHP formed inner‐sphere complexes on haematite in which some phosphate groups of the IHP molecule bonded with the haematite surface, and other dissociated phosphate groups were ionized. In the haematite– IHP–C d ternary system, the presence of aqueous C d( II ) increases IHP sorption and the ζ potential of haematite relative to that in the haematite– IHP binary system. The enhancement is more obvious at higher pHs , reversing the initial pH dependence of IHP sorption in the binary system. Similarly, the coexisting IHP promotes the retention of C d( II ) on haematite. The ATR‐FTIR spectroscopy indicates the formation of two structurally distinct ternary surface complexes (the H m– IHP–C d surface complex and the H m– C d– IHP–C d surface complex). Our results suggest that simultaneous sorption not only increases the sorption density of IHP and C d( II ), but also changes the surface complex configuration of IHP and Cd( II ) on haematite. Highlights The interactions between IHP and C d( II ) on haematite were investigated. The presence of C d( II ) increases IHP sorption and vice versa . IHP and C d( II ) co‐sorption is enhanced as pH increases. Two structurally distinct ternary surface complexes form on haematite surfaces.