Boosting brackish water treatment via integration of mesoporous γ-Al2O3NPs with thin-film nanofiltration membranes

Gamal K Hassan; Mona Al-Shemy; Abeer M Adel; Aly Al-Sayed

doi:10.1038/s41598-022-23914-2

Boosting brackish water treatment via integration of mesoporous γ-Al₂O₃NPs with thin-film nanofiltration membranes

Sci Rep. 2022 Nov 16;12(1):19666. doi: 10.1038/s41598-022-23914-2.

Authors

Gamal K Hassan¹, Mona Al-Shemy², Abeer M Adel², Aly Al-Sayed³

Affiliations

¹ Water Pollution Research Department, National Research Centre, 33 El Buhouth St. (Former El-Tahrir St.), P.O. Box 12622, Dokki, Giza, Egypt.
² Cellulose and Paper Department, National Research Center, 33 El-Bohouth St. (Former El-Tahrir St.), P.O. 12622, Dokki, Giza, Egypt.
³ Water Pollution Research Department, National Research Centre, 33 El Buhouth St. (Former El-Tahrir St.), P.O. Box 12622, Dokki, Giza, Egypt. al.mohamed@nrc.sci.eg.

Abstract

In this study, a simple method based on non-ionic surfactant polysorbates-80 was used to create mesoporous γ-Al₂O₃NPs. The properties of the prepared mesoporous alumina nanoparticles (Al₂O₃NPs) were verified using ATR-FTIR, XRD, SEM, TEM, DLS, and BET surface area analysis. Then, thin-film nanocomposite (TFN) nanofiltration membranes were fabricated by interfacial polymerization of embedded polyamide layers with varied contents (0.01 to 0.15 wt.%) of mesoporous γ-Al₂O₃NPs. The surface roughness, porosity, pore size, and contact angle parameters of all the prepared membranes were also determined. The performance of the fabricated membranes was investigated under various mesoporous γ-Al₂O₃NPs loads, time, and pressure conditions. Mesoporous γ-Al₂O₃NPs revealed an important role in raising both the membrane hydrophilicity and the surface negativity. The addition of 0.03 wt.% mesoporous γ-Al₂O₃NPs to the TFN membrane increased water flux threefold compared to the TF control (TFC) membrane, with maximum water flux reaching 96.5, 98, 60, and 52 L/(m².h) for MgSO₄, MgCl₂, Na₂SO₄, and NaCl influent solutions, respectively, with the highest salt rejection of 96.5%, 92.2%, 98.4%. The TFN-Al₂O₃ membrane was also able to soften water and remove polyvalent cations such as Mg²⁺ with a highly permeable flux. The TFN-Al₂O₃ membrane successfully removed the hardness of the applied water samples below the WHO limit compared to using merely the TFC membrane. Furthermore, the TFN-Al₂O₃ nanofiltration membrane unit proved to be a promising candidate for the desalination of real brine like that collected from the Safaga area, Egypt.