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Published on: September 26, 2016
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Homogeneous Diffusion Solid Model as a Realistic Approach to Describe Adsorption onto Materials with Different
E Sabio1, F Zamora2, C M González-García3
1Departamento Física Aplicada, Escuela de Ingenieras Industriales, Universidad de Extremadura, 06006, Badajoz, Spain. esabio@unex.es.
Nanoscale Research Letters
|December 14, 2016
Summary
This study models p-nitrophenol (PNP) adsorption onto activated carbons (ACs), revealing concentration waves explain adsorption rate drops. The findings link AC properties to adsorption kinetics for better material selection.
Area of Science:
- Environmental Chemistry
- Materials Science
- Chemical Engineering
Background:
- Adsorption is crucial for removing pollutants like p-nitrophenol (PNP).
- Understanding adsorption kinetics is key to optimizing removal processes.
- Activated carbons (ACs) are widely used adsorbents with diverse properties.
Purpose of the Study:
- To investigate the adsorption kinetics of PNP onto various commercial ACs.
- To develop and validate a model that accounts for adsorbent geometry.
- To correlate observed kinetic behaviors with AC characteristics.
Main Methods:
- Utilized a homogeneous diffusion solid model (HDSM) incorporating adsorbent shape.
- Employed the finite element method (FEM) for HDSM solution via COMSOL software.
- Conducted experimental adsorption studies with commercial activated carbons.
Main Results:
- The HDSM accurately described experimental adsorption kinetic patterns.
- Identified concentration wave formation as the cause for sharp adsorption rate declines.
- Visualized concentration changes in liquid and solid phases, linking kinetics to AC features.
Conclusions:
- The developed HDSM provides insights into PNP adsorption mechanisms on ACs.
- Adsorbent shape and textural properties significantly influence adsorption kinetics.
- The model facilitates understanding and predicting adsorption performance based on AC characteristics.
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