Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions

The objective of this work is to enhance the adsorbing performance of the natural Egyptian phyllosilicate mineral, glauconite (greensand), through surface modification to obtain a particular combination of physical and chemical properties. It was found that Zn removal increased from 84% to 94%, whil...

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Main Authors: Khaled A. Selim, Rasha Smair El-Tawil, Merit Rostom
Format: Article
Language:English
Published: Egyptian Petroleum Research Institute 2018-09-01
Series:Egyptian Journal of Petroleum
Online Access:http://www.sciencedirect.com/science/article/pii/S111006211730199X
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author Khaled A. Selim
Rasha Smair El-Tawil
Merit Rostom
author_facet Khaled A. Selim
Rasha Smair El-Tawil
Merit Rostom
author_sort Khaled A. Selim
collection DOAJ
description The objective of this work is to enhance the adsorbing performance of the natural Egyptian phyllosilicate mineral, glauconite (greensand), through surface modification to obtain a particular combination of physical and chemical properties. It was found that Zn removal increased from 84% to 94%, while Pb removal varied from 96.67% to 99% by using 10–25 g/l modified glauconite in a solution having 50 mg/l Zn2+ and 30 mg/l pb2+ ions. Adsorption data were investigated using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. Linear regression methods are used to determine adsorption capacities and optimum adsorption isotherms. R2 value of Langmuir isotherm model for pb2+ is higher than other models. The maximum monolayer coverage (Qo) from Langmuir isotherm model was calculated to be 15.363 and 21.654 mg/g and the separation factor indicating a favorable sorption experiment is 0.0324 and 0.13207 for Zn2+ and Pb2+ respectively. Also from Freundlich isotherm model, the intensities of adsorption (n) that indicated favorable sorption are 1.3036 and 1.364 for Zn2+ and Pb2+ respectively. The heat of sorption process was calculated from Temkin isotherm model to be 6.44101 and 4.1353 J/mol for Zn2+ and Pb2+ respectively, that indicated to the physisorption process which B < 20 kJ/mol so, Temkin isotherm is not fitted with experimental adsorption but the mean free energy was calculated from DRK isotherm which are 24.693 and 47.093 kJ/mol, where ED < 8 proved that the adsorption experiment followed a chemisorption process. So the relative adsorption capacity for metals was in the order Pb < Zn. Keywords: Adsorption, Heavy metals, Surface modification, Glauconite, Equilibrium isotherms
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issn 1110-0621
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publishDate 2018-09-01
publisher Egyptian Petroleum Research Institute
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spelling doaj-art-37da8ae882ce4247a85a373db86fb4a62025-08-20T03:18:35ZengEgyptian Petroleum Research InstituteEgyptian Journal of Petroleum1110-06212018-09-0127339340110.1016/j.ejpe.2017.07.003Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutionsKhaled A. Selim0Rasha Smair El-Tawil1Merit Rostom2Central Metallurgical Research & Development Institute, Minerals Technology Department, CMRDI, Cairo, EgyptNational Research Center, Inorganic Chemistry Department, NRC, Cairo, EgyptAcademy of Scientific Research and Technology, ASRT, Cairo, Box 11562, Egypt; Corresponding author.The objective of this work is to enhance the adsorbing performance of the natural Egyptian phyllosilicate mineral, glauconite (greensand), through surface modification to obtain a particular combination of physical and chemical properties. It was found that Zn removal increased from 84% to 94%, while Pb removal varied from 96.67% to 99% by using 10–25 g/l modified glauconite in a solution having 50 mg/l Zn2+ and 30 mg/l pb2+ ions. Adsorption data were investigated using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. Linear regression methods are used to determine adsorption capacities and optimum adsorption isotherms. R2 value of Langmuir isotherm model for pb2+ is higher than other models. The maximum monolayer coverage (Qo) from Langmuir isotherm model was calculated to be 15.363 and 21.654 mg/g and the separation factor indicating a favorable sorption experiment is 0.0324 and 0.13207 for Zn2+ and Pb2+ respectively. Also from Freundlich isotherm model, the intensities of adsorption (n) that indicated favorable sorption are 1.3036 and 1.364 for Zn2+ and Pb2+ respectively. The heat of sorption process was calculated from Temkin isotherm model to be 6.44101 and 4.1353 J/mol for Zn2+ and Pb2+ respectively, that indicated to the physisorption process which B < 20 kJ/mol so, Temkin isotherm is not fitted with experimental adsorption but the mean free energy was calculated from DRK isotherm which are 24.693 and 47.093 kJ/mol, where ED < 8 proved that the adsorption experiment followed a chemisorption process. So the relative adsorption capacity for metals was in the order Pb < Zn. Keywords: Adsorption, Heavy metals, Surface modification, Glauconite, Equilibrium isothermshttp://www.sciencedirect.com/science/article/pii/S111006211730199X
spellingShingle Khaled A. Selim
Rasha Smair El-Tawil
Merit Rostom
Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions
Egyptian Journal of Petroleum
title Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions
title_full Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions
title_fullStr Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions
title_full_unstemmed Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions
title_short Utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions
title_sort utilization of surface modified phyllosilicate mineral for heavy metals removal from aqueous solutions
url http://www.sciencedirect.com/science/article/pii/S111006211730199X
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AT rashasmaireltawil utilizationofsurfacemodifiedphyllosilicatemineralforheavymetalsremovalfromaqueoussolutions
AT meritrostom utilizationofsurfacemodifiedphyllosilicatemineralforheavymetalsremovalfromaqueoussolutions