Effect of Functional Groups and pH on the Affinity and Adsorption Capacity of Activated Carbon: Comparison of Homogeneous and Binary Langmuir Model Parameters

The adsorption of p -nitrophenol (an electrolyte) and nitrobenzene (a non-electrolyte) on activated carbon was carried out at 301 K under controlled pH conditions. The experimental isotherms were fitted to the homogeneous Langmuir model and the binary Langmuir model. Variation of the model parameter...

Full description

Saved in:
Bibliographic Details
Main Author: Sirous Nouri
Format: Article
Language:English
Published: SAGE Publishing 2003-07-01
Series:Adsorption Science & Technology
Online Access:https://doi.org/10.1260/026361703771953578
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1841564554222370816
author Sirous Nouri
author_facet Sirous Nouri
author_sort Sirous Nouri
collection DOAJ
description The adsorption of p -nitrophenol (an electrolyte) and nitrobenzene (a non-electrolyte) on activated carbon was carried out at 301 K under controlled pH conditions. The experimental isotherms were fitted to the homogeneous Langmuir model and the binary Langmuir model. Variation of the model parameters with solution pH was studied. The fitted parameters obtained from the Langmuir equations (homogeneous and binary models) showed that both the maximum amount of solute adsorbed (Q max ) and the adsorption affinity of the carbon (K 1 ) towards the electrolytic adsorbate exhibited the more significant decrease. Under pH conditions below the pK a value of p -nitrophenol (when the adsorbate existed in a molecular form), both the solubility of the adsorbate and the electron density of its aromatic ring were significant factors affected the extent of London dispersion interactions. At higher solution pH values, electrostatic forces had a significant impact on the extent of adsorption. The influence of pH must be considered in terms of its combined effect on the carbon surface and on the solute molecules. It was confirmed that the uptake of the molecular forms of the aromatic solutes was dependent on the substituents attached to the aromatic ring. The adsorption of p -nitrophenol at higher pH values depended on the concentration of the anionic form of the solute present in the aqueous solution.
format Article
id doaj-art-8e4798d00d824e7c8ca560958ccb0c97
institution Kabale University
issn 0263-6174
2048-4038
language English
publishDate 2003-07-01
publisher SAGE Publishing
record_format Article
series Adsorption Science & Technology
spelling doaj-art-8e4798d00d824e7c8ca560958ccb0c972025-01-02T22:37:56ZengSAGE PublishingAdsorption Science & Technology0263-61742048-40382003-07-012110.1260/026361703771953578Effect of Functional Groups and pH on the Affinity and Adsorption Capacity of Activated Carbon: Comparison of Homogeneous and Binary Langmuir Model ParametersSirous NouriThe adsorption of p -nitrophenol (an electrolyte) and nitrobenzene (a non-electrolyte) on activated carbon was carried out at 301 K under controlled pH conditions. The experimental isotherms were fitted to the homogeneous Langmuir model and the binary Langmuir model. Variation of the model parameters with solution pH was studied. The fitted parameters obtained from the Langmuir equations (homogeneous and binary models) showed that both the maximum amount of solute adsorbed (Q max ) and the adsorption affinity of the carbon (K 1 ) towards the electrolytic adsorbate exhibited the more significant decrease. Under pH conditions below the pK a value of p -nitrophenol (when the adsorbate existed in a molecular form), both the solubility of the adsorbate and the electron density of its aromatic ring were significant factors affected the extent of London dispersion interactions. At higher solution pH values, electrostatic forces had a significant impact on the extent of adsorption. The influence of pH must be considered in terms of its combined effect on the carbon surface and on the solute molecules. It was confirmed that the uptake of the molecular forms of the aromatic solutes was dependent on the substituents attached to the aromatic ring. The adsorption of p -nitrophenol at higher pH values depended on the concentration of the anionic form of the solute present in the aqueous solution.https://doi.org/10.1260/026361703771953578
spellingShingle Sirous Nouri
Effect of Functional Groups and pH on the Affinity and Adsorption Capacity of Activated Carbon: Comparison of Homogeneous and Binary Langmuir Model Parameters
Adsorption Science & Technology
title Effect of Functional Groups and pH on the Affinity and Adsorption Capacity of Activated Carbon: Comparison of Homogeneous and Binary Langmuir Model Parameters
title_full Effect of Functional Groups and pH on the Affinity and Adsorption Capacity of Activated Carbon: Comparison of Homogeneous and Binary Langmuir Model Parameters
title_fullStr Effect of Functional Groups and pH on the Affinity and Adsorption Capacity of Activated Carbon: Comparison of Homogeneous and Binary Langmuir Model Parameters
title_full_unstemmed Effect of Functional Groups and pH on the Affinity and Adsorption Capacity of Activated Carbon: Comparison of Homogeneous and Binary Langmuir Model Parameters
title_short Effect of Functional Groups and pH on the Affinity and Adsorption Capacity of Activated Carbon: Comparison of Homogeneous and Binary Langmuir Model Parameters
title_sort effect of functional groups and ph on the affinity and adsorption capacity of activated carbon comparison of homogeneous and binary langmuir model parameters
url https://doi.org/10.1260/026361703771953578
work_keys_str_mv AT sirousnouri effectoffunctionalgroupsandphontheaffinityandadsorptioncapacityofactivatedcarboncomparisonofhomogeneousandbinarylangmuirmodelparameters