Teaching adsorption chemistry by constructing surface complexation models (SCM) in PHREEQC
Author(s)
Bullen, Jay C
Landa-Cansigno, Oriana
Weiss, Dominik J
Type
Journal Article
Abstract
Adsorption modeling is important to understand and predict both how water contamination occurs, and how it might be prevented or remediated. Surface complexation models (SCM) help us understand adsorption under changing environmental conditions. This computational class introduces undergraduate students to adsorption and surface complexation and provides a foundation in geochemical modeling using freely available PHREEQC software from USGS. Practical capabilities are developed by (1) performing aqueous speciation reactions, (2) determining the surface charge of suspended metal oxide/mineral powders using potentiometric titration data, (3) calculating pH adsorption edges and adsorption isotherms, (4) applying PHREEQC to answer possible water treatment scenarios, and (5) using Visual Basic coding with loops to generate large data sets. This class is contextualized around arsenic contaminated groundwater and its treatment using iron oxide minerals, with hundreds of millions at risk worldwide (e.g., India, Bangladesh, Mexico). Participants report increases in their understanding of adsorption chemistry and confidence in the application of geochemical models to perform predictive SCM calculations.
Date Issued
2024-05-14
Date Acceptance
2024-03-20
Citation
Journal of Chemical Education, 2024, 101 (5), pp.1914-1924
ISSN
0021-9584
Publisher
American Chemical Society
Start Page
1914
End Page
1924
Journal / Book Title
Journal of Chemical Education
Volume
101
Issue
5
Copyright Statement
Copyright © 2024 The Authors. Published by American Chemical Society and Division of Chemical Education, Inc. This publication is licensed under CC-BY 4.0 .
License URL
Identifier
10.1021/acs.jchemed.3c01195
Subjects
ACTIVATED CARBON
Adsorption
Chemistry
Chemistry, Multidisciplinary
Colloids
Computational Chemistry
Computer-BasedLearning
Education & Educational Research
Education, Scientific Disciplines
Environmental Chemistry
Geochemistry
GOETHITE
Hands-On Learning
LANGMUIR
Modeling
PH
PHOSPHATE
Physical Sciences
REMEDIATION
Research
Science & Technology
Second-Year Undergraduate
Social Sciences
SPECTROSCOPY
Surface Science
WATER
Publication Status
Published
Date Publish Online
2024-04-03