Work

Modified polyvinylidene fluoride membranes for effective removal of iron ions (Fe2+) from water

Year: 2025

Type: article

Abstract: Paper introduces an efficient technique for removing excess Fe(II) ions from water using modified polyvinylidene fluoride membranes. Capability for Fe(II) removal was investigated for three types of PVDF membranes (pristine PVDF, PVDF/Fe 3 O 4 blend, and PVDF/Fe 3 O 4 blend membrane with additional immobilization of Fe 3 O 4 nanoparticles using polymer spacer. Structures and morphologies of membranes were analyzed through various techniques (IR, SEM, AFM, water contact angle, zeta potential), revealing that Fe 3 O 4 nanoparticles were successfully incorporated into the membrane matrix and/or the membrane surface. The surface modification resulted in increased hydrophilicity of the membrane surface, as indicated by a decrease of WCA from 106.1°±3° to 74.8°±2°. The isoelectric point changed from 3.5 ± 0.2 to 7.9 ± 0.2 after the attachment of polyethyleneimine (PEI) owing to the cationic nature of the polymer linker. Membranes were tested in an ultrafiltration process using polyacrylic acid (PAA) as an agent for the binding of Fe(II) into the coordination complex. The modified membranes demonstrated a hydrodynamic permeability coefficient of 17.1 LMH·bar -1 , which is approximately 2.5 times higher than the pristine PVDF membrane. The surface-modified PVDF membranes maintained a high rejection of Fe(II)-PAA coordination complex (97.1 and 99.4 %, respectively) at a pH of 8, leading to the decrease of concentration of Fe(II) in permeate from 20 ppm to 0.08 ppm and 0.11 ppm, meeting the standards set by the World Health Organization (0.3 ppm) and European Union Regulation (0.2 ppm). Modified PVDF/Fe 3 O 4 membranes show potential applications in water purification from heavy metals owing to many advantages, including higher flux rates and rejection ability.

Source: Results in Engineering

DOI: 10.1016/j.rineng.2025.104312

Authors: Halyna Bubela, Viktoriia Konovalova, Joanna Kujawa, Wojciech Kujawski

Institutions: National University of Kyiv-Mohyla Academy, Nicolaus Copernicus University

Language: English

Topic: Membrane Separation Technologies

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDG: Clean water and sanitation

Open Access status: gold

Estimated APC paid: $1,940