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

• Published in: Scientific reports 2022-11, Vol.12 (1), p.19666-22, Article 19666
• Main Authors: Hassan, Gamal K., Al-Shemy, Mona, Adel, Abeer M., Al-Sayed, Aly
• Format: Article
• Language: English
• Subjects: 639/638; 639/638/455; 639/638/455/957; Aluminum oxide; Brackish water; Cations; Contact angle; Desalination; Fluctuations; Humanities and Social Sciences; Magnesium chloride; Membranes; multidisciplinary; Nanocomposites; Nanofiltration; Nanoparticles; Nanotechnology; Polyamides; Pore size; Porosity; Salt rejection; Science; Science (multidisciplinary); Sodium chloride; Sodium sulfate; Thin films; Water analysis; Water sampling; Water treatment
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-23914-2

In this study, a simple method based on non-ionic surfactant polysorbates-80 was used to create mesoporous γ-Al 2 O 3 NPs. The properties of the prepared mesoporous alumina nanoparticles (Al 2 O 3 NPs) 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-Al 2 O 3 NPs. 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-Al 2 O 3 NPs loads, time, and pressure conditions. Mesoporous γ-Al 2 O 3 NPs revealed an important role in raising both the membrane hydrophilicity and the surface negativity. The addition of 0.03 wt.% mesoporous γ-Al 2 O 3 NPs 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/(m 2 .h) for MgSO 4 , MgCl 2 , Na 2 SO 4 , and NaCl influent solutions, respectively, with the highest salt rejection of 96.5%, 92.2%, 98.4%. The TFN-Al 2 O 3  membrane was also able to soften water and remove polyvalent cations such as Mg 2+ with a highly permeable flux. The TFN-Al 2 O 3 membrane successfully removed the hardness of the applied water samples below the WHO limit compared to using merely the TFC membrane. Furthermore, the TFN-Al 2 O 3 nanofiltration membrane unit proved to be a promising candidate for the desalination of real brine like that collected from the Safaga area, Egypt.