Predicting the Sorption of Aromatic Acids to Noncarbonized and Carbonized Sorbents

Author(s)

Gabriel Sigmund, Huichao Sun, Thilo Hofmann, Melanie Kah

Abstract

Approaches based on the octanol-water partition coefficient are commonly used to describe sorption of neutral organic compounds in environmental systems, but they are not suitable for organic acids, which can dissociate to form anions. We here investigate the applicability of an alternative approach based on the pH-dependent distribution ratio (D

_OW) to describe sorption of aromatic acids to sorbents representing different degrees of carbonization. Sorption isotherms for four structurally similar acids ((2,4-dichlorophenoxy)acetic acid (2,4-D), 4-chloro-2-15 methylphenoxy)acetic acid (MCPA), 4-(2,4-dichlorophenoxy)butanoic16 acid (2,4-DB), and 5-chloro-2-(2,4-dichlorophenoxy)phenol (triclosan)) were measured for 15 sorbents: fresh and carbonized wood shavings, pig manure, sewage sludge, carbon nanotubes, and activated carbon. Dissociation greatly affected the sorption of all acids. Sorption coefficients measured in the high pH range indicated that sorption of the anions ranged over several orders of magnitude and should not be neglected. Sorption trends for all sorbates and carbonized sorbents could be very well described by a single regression equation that included D

_OW of the sorbate and the specific surface area of the sorbent (R

² > 0.89). (Chemical Equation Presented).

Organisation(s)

External organisation(s)

University of Vienna

Journal

Environmental Science & Technology

Volume

50

Pages

3641-3648

No. of pages

8

ISSN

0013-936X

DOI

https://doi.org/10.1021/acs.est.5b06033

Publication date

2016

Peer reviewed

Yes

Austrian Fields of Science 2012

104023 Environmental chemistry, 104002 Analytical chemistry, 105906 Environmental geosciences

Keywords

ASJC Scopus subject areas

General Chemistry, Environmental Chemistry

Portal url

https://ucrisportal.univie.ac.at/en/publications/3f967255-6620-489e-9f52-7b7a8597ca8d