Remediation of manganese in mine impacted water by clay/manganese oxide hybrid adsorbent

Equilibrium, kinetics and thermodynamic studies

A. M. Muliwa, Maurice S. Onyango, A. Maity, Aoyi Ochieng

Research output: Contribution to journalArticle

Abstract

The present study investigated the potential of clay/manganese oxide (CMnO) hybrid adsorbent for the removal of manganese (Mn2+) from mine impacted water (MIW). The adsorbent was characterised by X-ray diffraction, Fourier transform infra-red (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmet–Teller and X-ray photoelectron spectroscopy (XPS) techniques. The equilibrium sorption capacity was depended on solution pH, MnO content of the clay, concentration and temperature. Isothermal adsorption highly inclined towards Freundlich isotherm model while thermodynamic parameters directed that the adsorption process was spontaneous and endothermic in nature. The adsorption kinetics of Mn2+ onto CMnO fitted well with the pseudo-second-order model and the value of activation energy of adsorption (Ea) was 32 kJ/mol, inferring that the adsorption proceeded by activated chemisorption process. Both intra-particle and film diffusion mechanisms were found to be the sorption rate-controlling steps. Experiments with real MIW water revealed that CMnO exhibited high Mn2+ removal efficiency in the presence of interfering ions but anions removal posed a great challenge. The XPS, FT-IR and pH analyses suggested that oxidation, complexation and ion-exchange mechanisms were responsible for Mn2+ removal by CMnO. These findings demonstrate that CMnO could serve as an inexpensive adsorbent for polishing Mn2+ polluted water.
Original languageEnglish
Pages (from-to)1-14
Number of pages14
JournalInternational Journal of Environmental Science and Technology
DOIs
Publication statusPublished - 2018

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manganese oxides
Manganese oxide
manganese oxide
adsorbents
remediation
Manganese
Remediation
Thermodynamics
thermodynamics
Adsorbents
manganese
Clay
Adsorption
clay
adsorption
kinetics
Kinetics
Water
X-ray photoelectron spectroscopy
Photoelectron Spectroscopy

Cite this

@article{9811b74259754741ab73fe18de5aac75,
title = "Remediation of manganese in mine impacted water by clay/manganese oxide hybrid adsorbent: Equilibrium, kinetics and thermodynamic studies",
abstract = "The present study investigated the potential of clay/manganese oxide (CMnO) hybrid adsorbent for the removal of manganese (Mn2+) from mine impacted water (MIW). The adsorbent was characterised by X-ray diffraction, Fourier transform infra-red (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmet–Teller and X-ray photoelectron spectroscopy (XPS) techniques. The equilibrium sorption capacity was depended on solution pH, MnO content of the clay, concentration and temperature. Isothermal adsorption highly inclined towards Freundlich isotherm model while thermodynamic parameters directed that the adsorption process was spontaneous and endothermic in nature. The adsorption kinetics of Mn2+ onto CMnO fitted well with the pseudo-second-order model and the value of activation energy of adsorption (Ea) was 32 kJ/mol, inferring that the adsorption proceeded by activated chemisorption process. Both intra-particle and film diffusion mechanisms were found to be the sorption rate-controlling steps. Experiments with real MIW water revealed that CMnO exhibited high Mn2+ removal efficiency in the presence of interfering ions but anions removal posed a great challenge. The XPS, FT-IR and pH analyses suggested that oxidation, complexation and ion-exchange mechanisms were responsible for Mn2+ removal by CMnO. These findings demonstrate that CMnO could serve as an inexpensive adsorbent for polishing Mn2+ polluted water.",
author = "Muliwa, {A. M.} and Onyango, {Maurice S.} and A. Maity and Aoyi Ochieng",
year = "2018",
doi = "10.1007/s13762-018-1817-5",
language = "English",
pages = "1--14",
journal = "International Journal of Environmental Science and Technology",
issn = "1735-1472",
publisher = "CEERS",

}

TY - JOUR

T1 - Remediation of manganese in mine impacted water by clay/manganese oxide hybrid adsorbent

T2 - Equilibrium, kinetics and thermodynamic studies

AU - Muliwa, A. M.

AU - Onyango, Maurice S.

AU - Maity, A.

AU - Ochieng, Aoyi

PY - 2018

Y1 - 2018

N2 - The present study investigated the potential of clay/manganese oxide (CMnO) hybrid adsorbent for the removal of manganese (Mn2+) from mine impacted water (MIW). The adsorbent was characterised by X-ray diffraction, Fourier transform infra-red (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmet–Teller and X-ray photoelectron spectroscopy (XPS) techniques. The equilibrium sorption capacity was depended on solution pH, MnO content of the clay, concentration and temperature. Isothermal adsorption highly inclined towards Freundlich isotherm model while thermodynamic parameters directed that the adsorption process was spontaneous and endothermic in nature. The adsorption kinetics of Mn2+ onto CMnO fitted well with the pseudo-second-order model and the value of activation energy of adsorption (Ea) was 32 kJ/mol, inferring that the adsorption proceeded by activated chemisorption process. Both intra-particle and film diffusion mechanisms were found to be the sorption rate-controlling steps. Experiments with real MIW water revealed that CMnO exhibited high Mn2+ removal efficiency in the presence of interfering ions but anions removal posed a great challenge. The XPS, FT-IR and pH analyses suggested that oxidation, complexation and ion-exchange mechanisms were responsible for Mn2+ removal by CMnO. These findings demonstrate that CMnO could serve as an inexpensive adsorbent for polishing Mn2+ polluted water.

AB - The present study investigated the potential of clay/manganese oxide (CMnO) hybrid adsorbent for the removal of manganese (Mn2+) from mine impacted water (MIW). The adsorbent was characterised by X-ray diffraction, Fourier transform infra-red (FT-IR), scanning electron microscopy (SEM), Brunauer–Emmet–Teller and X-ray photoelectron spectroscopy (XPS) techniques. The equilibrium sorption capacity was depended on solution pH, MnO content of the clay, concentration and temperature. Isothermal adsorption highly inclined towards Freundlich isotherm model while thermodynamic parameters directed that the adsorption process was spontaneous and endothermic in nature. The adsorption kinetics of Mn2+ onto CMnO fitted well with the pseudo-second-order model and the value of activation energy of adsorption (Ea) was 32 kJ/mol, inferring that the adsorption proceeded by activated chemisorption process. Both intra-particle and film diffusion mechanisms were found to be the sorption rate-controlling steps. Experiments with real MIW water revealed that CMnO exhibited high Mn2+ removal efficiency in the presence of interfering ions but anions removal posed a great challenge. The XPS, FT-IR and pH analyses suggested that oxidation, complexation and ion-exchange mechanisms were responsible for Mn2+ removal by CMnO. These findings demonstrate that CMnO could serve as an inexpensive adsorbent for polishing Mn2+ polluted water.

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