Study of the iron(III)-modified clinoptilolite in the adsorption of phosphate from aqueous medium: mechanism and kinetics
Abstract
Clinoptilolite-rich tuff (Z) enriched with Fe(III) was studied in the removal of phosphate ions present in aqueous medium at pH = 6.5. Fe(III) modification was performed by a simple wet impregnation giving the product (FeZ) with about 18 wt% Fe. Transmission electron microscopy showed the presence of a flaky Fe(III) amorphous precipitate on the clinoptilolite sheets and a preserved clinoptilolite crystallinity. The modification increased the specific surface area from 28.6 to 140.3 m(2) g(-1). FeZ effectively adsorbed phosphate, the removal rate at 298 K varying from 86% to 42.5% (for C-0 = 50 mg dm(-3) and C-0 = 400 mg dm(-3)). The sorption isotherms were in accord with the Langmuir model, giving for the Langmuir constant (R-L) values in the range 0-1 that are characteristic of a favourable adsorption. The data for adsorption kinetics were best described by the pseudo-second-order model suggesting chemisorption as the phosphate sorption mechanism. Intra-particle diffusion was present ...in the adsorption, but it was not the rate-limiting step. A P-31 static spin-echo mapping nuclear magnetic resonance (NMR) measurement was performed for studying the phosphate-FeZ interaction. The results showed that the phosphate adsorption on FeZ proceeds through electrostatic interactions and covalent bonding, the latter being more pronounced.
Keywords:
Clinoptilolite / Phosphate adsorption / Adsorption mechanism / P-31 NMR / Kinetics / TEMSource:
Desalination and Water Treatment, 2017, 78, 231-240Publisher:
- Desalination Publ, Hopkinton
Funding / projects:
DOI: 10.5004/dwt.2017.20875
ISSN: 1944-3994
WoS: 000408475200023
Scopus: 2-s2.0-85025810628
Institution/Community
Tehnološko-metalurški fakultetTY - JOUR AU - Kaplanec, Iva AU - Recnik, Aleksander AU - Mali, Gregor AU - Rajić, Nevenka PY - 2017 UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/3581 AB - Clinoptilolite-rich tuff (Z) enriched with Fe(III) was studied in the removal of phosphate ions present in aqueous medium at pH = 6.5. Fe(III) modification was performed by a simple wet impregnation giving the product (FeZ) with about 18 wt% Fe. Transmission electron microscopy showed the presence of a flaky Fe(III) amorphous precipitate on the clinoptilolite sheets and a preserved clinoptilolite crystallinity. The modification increased the specific surface area from 28.6 to 140.3 m(2) g(-1). FeZ effectively adsorbed phosphate, the removal rate at 298 K varying from 86% to 42.5% (for C-0 = 50 mg dm(-3) and C-0 = 400 mg dm(-3)). The sorption isotherms were in accord with the Langmuir model, giving for the Langmuir constant (R-L) values in the range 0-1 that are characteristic of a favourable adsorption. The data for adsorption kinetics were best described by the pseudo-second-order model suggesting chemisorption as the phosphate sorption mechanism. Intra-particle diffusion was present in the adsorption, but it was not the rate-limiting step. A P-31 static spin-echo mapping nuclear magnetic resonance (NMR) measurement was performed for studying the phosphate-FeZ interaction. The results showed that the phosphate adsorption on FeZ proceeds through electrostatic interactions and covalent bonding, the latter being more pronounced. PB - Desalination Publ, Hopkinton T2 - Desalination and Water Treatment T1 - Study of the iron(III)-modified clinoptilolite in the adsorption of phosphate from aqueous medium: mechanism and kinetics EP - 240 SP - 231 VL - 78 DO - 10.5004/dwt.2017.20875 ER -
@article{ author = "Kaplanec, Iva and Recnik, Aleksander and Mali, Gregor and Rajić, Nevenka", year = "2017", abstract = "Clinoptilolite-rich tuff (Z) enriched with Fe(III) was studied in the removal of phosphate ions present in aqueous medium at pH = 6.5. Fe(III) modification was performed by a simple wet impregnation giving the product (FeZ) with about 18 wt% Fe. Transmission electron microscopy showed the presence of a flaky Fe(III) amorphous precipitate on the clinoptilolite sheets and a preserved clinoptilolite crystallinity. The modification increased the specific surface area from 28.6 to 140.3 m(2) g(-1). FeZ effectively adsorbed phosphate, the removal rate at 298 K varying from 86% to 42.5% (for C-0 = 50 mg dm(-3) and C-0 = 400 mg dm(-3)). The sorption isotherms were in accord with the Langmuir model, giving for the Langmuir constant (R-L) values in the range 0-1 that are characteristic of a favourable adsorption. The data for adsorption kinetics were best described by the pseudo-second-order model suggesting chemisorption as the phosphate sorption mechanism. Intra-particle diffusion was present in the adsorption, but it was not the rate-limiting step. A P-31 static spin-echo mapping nuclear magnetic resonance (NMR) measurement was performed for studying the phosphate-FeZ interaction. The results showed that the phosphate adsorption on FeZ proceeds through electrostatic interactions and covalent bonding, the latter being more pronounced.", publisher = "Desalination Publ, Hopkinton", journal = "Desalination and Water Treatment", title = "Study of the iron(III)-modified clinoptilolite in the adsorption of phosphate from aqueous medium: mechanism and kinetics", pages = "240-231", volume = "78", doi = "10.5004/dwt.2017.20875" }
Kaplanec, I., Recnik, A., Mali, G.,& Rajić, N.. (2017). Study of the iron(III)-modified clinoptilolite in the adsorption of phosphate from aqueous medium: mechanism and kinetics. in Desalination and Water Treatment Desalination Publ, Hopkinton., 78, 231-240. https://doi.org/10.5004/dwt.2017.20875
Kaplanec I, Recnik A, Mali G, Rajić N. Study of the iron(III)-modified clinoptilolite in the adsorption of phosphate from aqueous medium: mechanism and kinetics. in Desalination and Water Treatment. 2017;78:231-240. doi:10.5004/dwt.2017.20875 .
Kaplanec, Iva, Recnik, Aleksander, Mali, Gregor, Rajić, Nevenka, "Study of the iron(III)-modified clinoptilolite in the adsorption of phosphate from aqueous medium: mechanism and kinetics" in Desalination and Water Treatment, 78 (2017):231-240, https://doi.org/10.5004/dwt.2017.20875 . .