University of Massachusetts Amherst , USA

Baoshan Xing is Full Professor of Environmental & Soil Chemistry at Stockbridge School of Agriculture, University of Massachusetts Amherst (USA) ...

... He received his Ph.D. from University of Alberta (Canada). He is a leading authority on the environmental fate and processes of the contaminants of emerging concern (e.g., PPCPs, nanomaterials). He group published over 400 refereed journal articles with citations over 36,200 and h-index currently at 94 (Google Scholar). He is one of the “Highly Cited Researchers” since 2014 (5 years in a row) recognized by the Clarivate Analytics for “the best and brightest scientific minds of our time”. Xing serves on several journal editorial boards & scientific advisory committees. He is the director of his university off-campus M.Sc. of soil science program, and co-director of environmental science program. He won many awards and his research program is internationally recognized.

 

Abstract


MECHANISTIC INSIGHT INTO ADSORPTION MECHANISM OF IONIZABLE ORGANIC COMPOUNDS ON CARBONACEOUS MATERIALS THROUGH USING CARBON NANOTUBES

Baoshan Xing1, *

1 Stockbridge School of Agricuilture, University of Massachusetts, Amherst, MA 01003, USA

Adsorption is one of the most important processes in the environment regulating the fate and bioavailability of organic contaminants including ionizable antibiotics. Carbonaceous materials such as black carbon, biochar, and activated carbon are a principal group of adsorbents. The often discussed molecular mechanisms in the literature for sorption of organic compounds by these carbonaceous materials include: π-π stacking, hydrophobic effect, electrostatic attraction, cation-π force, cation bridging, and H-bond. However, these mechanisms are not able to explain the strong adsorption of negatively charged organic molecular species on the negatively charged surface of carbonaceous materials. In this presentation, charge-assisted H-bond [(-)CAHB] will be demonstrated to be a key mechanism for adsorption of ionizable organic compounds onto the surface of carbonaceous materials. Experimental, molecular and thermodynamic evidence for [(-)CAHB] will be presented. Formation of [(-)CAHB] has major significance and implication for the fate of ionizable antibiotics in the environment, and carbon sequestration in soils.


 Li, X.Y., B. Gámiz, Y.Q. Wang, J.J. Pignatello and B.S. Xing. 2015. Competitive sorption used to probe strong hydrogen bonding sites for weak organic acids on carbon nanotubes. Environ. Sci. Technol. 49: 1409–1417.