Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters

This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe<sub>3</sub>O<sub&...

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Main Authors: Yesica Vicente-Martínez, Manuel Caravaca, Antonio Soto-Meca, Miguel Ángel Martín-Pereira, María del Carmen García-Onsurbe
Format: Article
Language:English
Published: MDPI AG 2021-06-01
Series:Water
Subjects:
Online Access:https://www.mdpi.com/2073-4441/13/13/1757
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author Yesica Vicente-Martínez
Manuel Caravaca
Antonio Soto-Meca
Miguel Ángel Martín-Pereira
María del Carmen García-Onsurbe
author_facet Yesica Vicente-Martínez
Manuel Caravaca
Antonio Soto-Meca
Miguel Ángel Martín-Pereira
María del Carmen García-Onsurbe
author_sort Yesica Vicente-Martínez
collection DOAJ
description This paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe<sub>3</sub>O<sub>4</sub>@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe<sub>3</sub>O<sub>4</sub>@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increased. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.
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spelling doaj.art-45208580eb8840e998d20357e494db6a2023-11-22T01:46:02ZengMDPI AGWater2073-44412021-06-011313175710.3390/w13131757Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from WatersYesica Vicente-Martínez0Manuel Caravaca1Antonio Soto-Meca2Miguel Ángel Martín-Pereira3María del Carmen García-Onsurbe4Department of Science, University Centre of Defence at the Spanish Air Force Academy, Ministry of Defence-Technical University of Cartagena, C/Coronel López Peña s/n, Santiago de la Ribera, 30720 Murcia, SpainDepartment of Science, University Centre of Defence at the Spanish Air Force Academy, Ministry of Defence-Technical University of Cartagena, C/Coronel López Peña s/n, Santiago de la Ribera, 30720 Murcia, SpainDepartment of Science, University Centre of Defence at the Spanish Air Force Academy, Ministry of Defence-Technical University of Cartagena, C/Coronel López Peña s/n, Santiago de la Ribera, 30720 Murcia, SpainDepartment of Science, University Centre of Defence at the Spanish Air Force Academy, Ministry of Defence-Technical University of Cartagena, C/Coronel López Peña s/n, Santiago de la Ribera, 30720 Murcia, SpainCampus Alfonso XIII, Technical University of Cartagena, 30203 Cartagena, SpainThis paper presents a novel procedure for the treatment of contaminated water with high concentrations of nitrates, which are considered as one of the main causes of the eutrophication phenomena. For this purpose, magnetic nanoparticles functionalized with silver (Fe<sub>3</sub>O<sub>4</sub>@AgNPs) were synthesized and used as an adsorbent of nitrates. Experimental conditions, including the pH, adsorbent and adsorbate dose, temperature and contact time, were analyzed to obtain the highest adsorption efficiency for different concentration of nitrates in water. A maximum removal efficiency of 100% was reached for 2, 5, 10 and 50 mg/L of nitrate at pH = 5, room temperature, and 50, 100, 250 and 500 µL of Fe<sub>3</sub>O<sub>4</sub>@AgNPs, respectively. The characterization of the adsorbent, before and after adsorption, was performed by energy dispersive X-ray spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller analysis and Fourier-transform infrared spectroscopy. Nitrates can be desorbed, and the adsorbent can be reused using 500 µL of NaOH solution 0.01 M, remaining unchanged for the first three cycles, and exhibiting 90% adsorption efficiency after three regenerations. A deep study on equilibrium isotherms reveals a pH-dependent behavior, characterized by Langmuir and Freundlich models at pH = 5 and pH = 1, respectively. Thermodynamic studies were consistent with physicochemical adsorption for all experiments but showed a change from endothermic to exothermic behavior as the temperature increased. Interference studies of other ions commonly present in water were carried out, enabling this procedure as very selective for nitrate ions. In addition, the method was applied to real samples of seawater, showing its ability to eliminate the total nitrate content in eutrophized waters.https://www.mdpi.com/2073-4441/13/13/1757adsorptionmagnetic nanoparticlesnitratepollutant removalwater remediation
spellingShingle Yesica Vicente-Martínez
Manuel Caravaca
Antonio Soto-Meca
Miguel Ángel Martín-Pereira
María del Carmen García-Onsurbe
Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters
Water
adsorption
magnetic nanoparticles
nitrate
pollutant removal
water remediation
title Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters
title_full Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters
title_fullStr Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters
title_full_unstemmed Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters
title_short Adsorption Studies on Magnetic Nanoparticles Functionalized with Silver to Remove Nitrates from Waters
title_sort adsorption studies on magnetic nanoparticles functionalized with silver to remove nitrates from waters
topic adsorption
magnetic nanoparticles
nitrate
pollutant removal
water remediation
url https://www.mdpi.com/2073-4441/13/13/1757
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AT antoniosotomeca adsorptionstudiesonmagneticnanoparticlesfunctionalizedwithsilvertoremovenitratesfromwaters
AT miguelangelmartinpereira adsorptionstudiesonmagneticnanoparticlesfunctionalizedwithsilvertoremovenitratesfromwaters
AT mariadelcarmengarciaonsurbe adsorptionstudiesonmagneticnanoparticlesfunctionalizedwithsilvertoremovenitratesfromwaters