Functionalized carbon/alumina/silica nanofibrous membrane: preparation, characterization and heavy metal filtration performance

• Published in: Desalination and water treatment 2021-09, Vol.233, p.81-97
• Main Authors: Sepahdar, A., Almasian, A., Javar, H. Akbari
• Format: Article
• Language: English
• Subjects: Adsorption– filtration membrane; Carbon nanofibers; Filtration performance; Functionalized nanofibers
• ISSN: 1944-3986; 1944-3986
• DOI: 10.5004/dwt.2021.27520

In this paper, carbon-based membranes with an extremely high surface area were prepared as a filtration–adsorption membrane for separating Pb2+ and Cd2+ metal ions from aqueous solutions. High surface area value (1,751.1 m2 g–1) and unique microscopic structure of nanofibers were obtained with the use of polystyrene (PS) and polyethylene glycol (PEG) as organic and degradable compounds along with aluminum salt and tetraethyl orthosilicate (TEOS) in the polyacrylonitrile (PAN) matrix. The use of aluminum salt and TEOS in the PAN matrix not only influenced the Brunauer– Emmett–Teller value but also enhanced the mechanical properties of membranes. The role of PS, PEG, silica and alumina on surface area and adsorption capacity of heavy metals were evaluated. In order to improve the separation and adsorption ability of the membrane, a functionalization process was performed by triethylenetetramine. The functionalization changed some mechanical properties and hydrophilicity of the membrane resulted in better antifouling property and higher permeability. The antifouling and rejection efficiency of membranes were investigated at two different pH levels. The static adsorption capacity and the rejection efficiency of the functionalized membrane were 450.11, 431.48 mg g–1 and 93.25%, 90.11% for Pb and Cd, respectively. The role of mesopores on the adsorption of heavy metals was investigated by adsorption kinetic. The filtration studies revealed that the synthesized membrane has good filtration performance even after 10 regeneration cycles.