Yale Univ., New Haven, CT (United States); Yale Univ., New Haven, CT (United States). Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT); Yale Univ., New Haven, CT (United States). Yale Center for Green Chemistry and Green Engineering; Princeton Univ., NJ (United States)
Yale Univ., New Haven, CT (United States); Yale Univ., New Haven, CT (United States). Yale Center for Green Chemistry and Green Engineering
Yale Univ., New Haven, CT (United States)
Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source II (NSLS-II)
Yale Univ., New Haven, CT (United States); Yale Univ., New Haven, CT (United States). Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT); Yale Univ., New Haven, CT (United States). Yale Center for Green Chemistry and Green Engineering
The ability of transition metal chitosan complexes (TMCs) of varying valence and charge to selectively adsorb As(III) and As(V) over their strongest adsorptive competitor, phosphate is examined. Fe(III)-chitosan, Cu(II)-chitosan, Al(III)-chitosan, Ni(II)-chitosan, and Zn(II)-chitosan are synthesized, characterized via Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR) and X-ray Diffractometry (XRD), and their selective sorption capabilities towards arsenite and arsenate over phosphate are evaluated. It was found that the stability of the metal-chitosan complexes varied, with Al(III)- and Zn(II)-chitosan forming unstable complexes resulting in precipitation of gibbsite, and Wulfingite and zincite, respectively. Cu(II)-, Ni(II)-, and Fe(III)- chitosan formed a mixture of monodentate and bidentate complexes. The TMCs which formed the bidentate complex (Cu(II)-, Ni(II)-, and Fe(III)-) showed greater adsorption capability for arsenate in competitive systems with phosphate. Using the binary separation factor αt/c, it can be shown that only Fe(III)-chitosan is selective for As(V) and As(III) over phosphate. Density Functional Theory (DFT) modeling and extended X-ray absorption fine structure (EXAFS) determined that Fe(III)-chitosan and Ni(II)-chitosan adsorbed As(V) and As(III) via inner-sphere complexation, while Cu(II)-chitosan formed mainly outer-sphere complexes with As(V) and As(III). These differences in complexation likely result in the observed differences in selective adsorption capability towards As(V) and As(III) over phosphate.
Pincus, Lauren N., et al. "Selective adsorption of arsenic over phosphate by transition metal cross-linked chitosan." Chemical Engineering Journal, vol. 412, Jan. 2021. https://doi.org/10.1016/j.cej.2021.128582
Pincus, Lauren N., Petrović, Predrag V., Gonzalez, Isabel S., et al., "Selective adsorption of arsenic over phosphate by transition metal cross-linked chitosan," Chemical Engineering Journal 412 (2021), https://doi.org/10.1016/j.cej.2021.128582
@article{osti_1785109,
author = {Pincus, Lauren N. and Petrović, Predrag V. and Gonzalez, Isabel S. and Stavitski, Eli and Fishman, Zachary S. and Rudel, Holly E. and Anastas, Paul T. and Zimmerman, Julie B.},
title = {Selective adsorption of arsenic over phosphate by transition metal cross-linked chitosan},
annote = {The ability of transition metal chitosan complexes (TMCs) of varying valence and charge to selectively adsorb As(III) and As(V) over their strongest adsorptive competitor, phosphate is examined. Fe(III)-chitosan, Cu(II)-chitosan, Al(III)-chitosan, Ni(II)-chitosan, and Zn(II)-chitosan are synthesized, characterized via Attenuated Total Reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR) and X-ray Diffractometry (XRD), and their selective sorption capabilities towards arsenite and arsenate over phosphate are evaluated. It was found that the stability of the metal-chitosan complexes varied, with Al(III)- and Zn(II)-chitosan forming unstable complexes resulting in precipitation of gibbsite, and Wulfingite and zincite, respectively. Cu(II)-, Ni(II)-, and Fe(III)- chitosan formed a mixture of monodentate and bidentate complexes. The TMCs which formed the bidentate complex (Cu(II)-, Ni(II)-, and Fe(III)-) showed greater adsorption capability for arsenate in competitive systems with phosphate. Using the binary separation factor αt/c, it can be shown that only Fe(III)-chitosan is selective for As(V) and As(III) over phosphate. Density Functional Theory (DFT) modeling and extended X-ray absorption fine structure (EXAFS) determined that Fe(III)-chitosan and Ni(II)-chitosan adsorbed As(V) and As(III) via inner-sphere complexation, while Cu(II)-chitosan formed mainly outer-sphere complexes with As(V) and As(III). These differences in complexation likely result in the observed differences in selective adsorption capability towards As(V) and As(III) over phosphate.},
doi = {10.1016/j.cej.2021.128582},
url = {https://www.osti.gov/biblio/1785109},
journal = {Chemical Engineering Journal},
issn = {ISSN 1385-8947},
volume = {412},
place = {United States},
publisher = {Elsevier},
year = {2021},
month = {01}}
