resumo
The global scarcity of phosphorus and increasing concern over aquatic eutrophication are driving greater interest in phosphorus (P) recovery from water. Emerging materials, such as Layered Double Hydroxides (LDH) or their calcined forms, Layered Double Oxides (LDO), are gaining attention for their excellent sorption capacity. This study aims to evaluate the performance of three different materials, a calcined MgAl-LDO, ZnAlNO3, and its calcined product ZnAl-LDO for phosphate removal in batch conditions. The foremost strength of this article is that the materials under studied are manufactured on a large scale, thereby facilitating the scaling up for practical applications. The materials were characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) before and after sorption. After calcination, MgAl-LDO reacquires its initial structure when in contact with an aqueous solution due to the "memory effect", whereas ZnAl-LDO maintains its metal oxide state. Phosphorus removal by both calcined and non-calcined materials followed a pseudo-second-order kinetics. The ZnAlNO3 revealed a higher removal capacity when compared to ZnAl-LDO, which indicates that, in this case, the calcination does not improve its sorption capacity. The equilibrium study using ZnAlNO3 demonstrated that the Langmuir isotherm provided the best fit for the experimental data, with a maximum phosphorus loading capacity of 84 mg g-1. Overall, ZnAlNO3 appears to be a promising sorbent for the efficient and cost-effective removal of phosphate ions from eutrophicated water streams.
palavras-chave
PHOSPHATE REMOVAL; AQUEOUS-SOLUTIONS; ADSORPTION; KINETICS; ISOTHERMS; CAPACITY; INSIGHT; LDHS
categoria
Chemistry
autores
Borges, ID; Rocha, CM; Maia, F; Silva, CM; Quina, MJ
nossos autores
Carlos Manuel Silva
Professor associadoProjectos
Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
Ines D. Borges acknowledges the financial support by the Portuguese Fundac & atilde;o para a Ciencia e a Tecnologia (FCT) grant PD/BD/153599/2022. This work was partially supported by project "NATURAL - Nano-argilas para remoc & atilde;o/captura de fosfatos (P) e sua reutilizac & atilde;o como fertilizante", with the reference CENTER-01-0247-FEDER-047080, supported by the Centro Portugal Regional Operational Programme (CENTRO 2020), under the Portugal 2020 (P 2020) Partnership Agreement, through the European Regional Development Fund (ERDF). This work was developed within the scope of the project CICECO - Aveiro Institute of Materials, UID/50011/2025 (DOI: 10.54499/UID/50011/2025) & LA/P/0006/2020 (DOI: 10.54499/LA/P/0006/2020), financed by national funds through the FCT/MCTES (PIDDAC). This work was carried out within the CERES Centre and supported by national funds from FCT through the projects https://doi.org/10.54499/UID/00102/2025 and https://doi.org/10.54499/UID/PRR/00102/2025.