University of Oulu

Runtti H, Sundhararasu E, Pesonen J, Tuomikoski S, Hu T, Lassi U, Kangas T. Removal of Ammonium Ions from Aqueous Solutions Using Alkali-Activated Analcime as Sorbent. ChemEngineering. 2023; 7(1):5.

Removal of ammonium ions from aqueous solutions using alkali-activated analcime as sorbent

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Author: Runtti, Hanna1; Sundhararasu, Elavarasi1; Pesonen, Janne1;
Organizations: 1Research Unit of Sustainable Chemistry, University of Oulu, FI-90570 Oulu, Finland
2Kokkola University Consortium Chydenius, University of Jyvaskyla, FI-67100 Kokkola, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.7 MB)
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Language: English
Published: Multidisciplinary Digital Publishing Institute, 2023
Publish Date: 2023-01-17


Five alkali-activated analcime (ANA) sorbents (ANA-MK 1, ANA 2, ANA 3, ANA-MK 4, and ANA-MK 5) were developed for ammonium (NH₄⁺) ion removal. Acid treatment and calcination were used as pre-treatments for analcime, and metakaolin (MK) was used as a blending agent in three sorbents. Sorption experiments were performed to evaluate the effects of sorbent dosage (1–20 g L⁻¹), initial NH₄⁺ ion concentration (5–1000 g L⁻¹), and contact time (1 min–24 h). ANA-MK 1, ANA 2, and ANA-MK 4 were the most efficient sorbents for NH₄⁺ ion removal, with a maximum experimental sorption uptake of 29.79, 26.00, and 22.24 mg g⁻¹, respectively. ANA 3 and ANA-MK 5 demonstrated lower sorption capacities at 7.18 and 12.65 mg g⁻¹, respectively. The results for the sorption of NH₄⁺ ions onto the alkali-activated analcime surfaces were modeled using several isotherms. The Langmuir, Freundlich, Sips, and Bi-Langmuir isotherms were the best isotherm models to represent the studied systems. The results of the kinetic studies showed the maximum NH₄⁺ ion removal percentage of the sorbents was ~80%, except for ANA-MK 5, which had a ~70% removal. Moreover, the pseudo-first-order, pseudo-second-order, and Elovich models were applied to the experimental data. The results showed that the sorption process for ANA-MK 1, ANA 2, ANA 3, and ANA-MK 4 followed the Elovich model, whereas the pseudo-second-order model provided the best correlation for ANA-MK 5.

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Series: ChemEngineering
ISSN: 2305-7084
ISSN-E: 2305-7084
ISSN-L: 2305-7084
Volume: 7
Issue: 1
Article number: 5
DOI: 10.3390/chemengineering7010005
Type of Publication: A1 Journal article – refereed
Field of Science: 116 Chemical sciences
Funding: This study was conducted as part of WaterPro (ERDF Project No. A74635, funded by the Central Ostrobothnia Regional Council, the European Union, the European Regional Development Fund, and the Leverage from the EU) and was supported by Maaja vesitekniikan tukiry and K.H. Renlund Foundation.
Copyright information: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (