Optimization of polyvinylpyrrolidone-SiO₂ microfiber membranes for efficient water purification

Author(s)

Alvarenga, Augusto D. ; Andre, Rafaela S. ; Alves, Ana Laura M. M. ; Correa, Daniel S.

• Document type: Journal article
• Source: JOURNAL OF WATER PROCESS ENGINEERING; v. 67, p. 14-pg., 2024-09-10.

Abstract

Efficient removal of persistent organic pollutants from water remains a significant challenge for conventional water treatment methods. Materials containing carbon and/or SiO2 have demonstrated remarkable adsorption capacities for these pollutants. In this study, we explore the combination of carbonaceous structures and SiO2 through calcination (200 degrees C to 500 degrees C) of microfiber membranes produced with polyvinylpyrrolidone and tetraethyl orthosilicate by the solution blow spinning method, followed by chemical activation using NaOH. The developed membranes were thoroughly characterized to assess their physical and chemical properties. The performance of the ecofriendly microfiber membranes was evaluated in both batch and fixed-bed adsorption systems for methylene blue. Our findings revealed that chemical activation with NaOH effectively removed SiO2 from fibers, increasing the surface area and promoting oxidation of residual carbon, resulting in adsorption efficiency by at least 1000 %. Specifically, the fibers exhibited an average batch adsorption capacity of 873.3 mg/g, with a maximum capacity reaching 1862.4 mg/g. Fixed bed adsorption achieved 273.6 mg/g. Besides, the membrane was also tested for other organic pollutants and metal ions. The production cost of these microfibers was US$1.82/g. The strategy employed in this study, involving the creation of pores and increasing the surface area of fibers proved to be a promising approach for removing dyes and can be expanded to other water pollutants. (AU)

• FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants