Preparation, characterization of PVDF/PVP/MMT mixed matrix membranes and their application for the removal of heavy metals from wastewater

Abstract

Different composition of mixed matrix membranes comprising Polyvinylidene fluoride (PVDF) as base polymer, Polyvinylpyrrolidone and Montmorillonite clay as additive was fabricated by phase inversion technique using N, N-Dimethylacetamide as a solvent. Furnished membrane samples were characterized by X-Ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM) for phase identification, functional group analysis, thermal stability, determination of surface morphology and textural features which show that PVP and MMT successfully modified PVDF membrane and resulted in PVDF/PVP/MMT mixed matrix membrane. Different membrane characteristics such as pure water flux, water content, porosity, shrinkage ratio, fouling recovery ratio and solute rejection were studied and calculated. The contemporary membrane (PPM5) having 5 wt. % of MMT represented the increase in pure water flux, porosity, and fouling recovery ratio from 13.8 Lm⁻²h⁻¹, 33% and 52% to 19.8 Lm⁻²h⁻¹, 85%, and 87%, respectively. The PPM5 also shows a reduction in shrinkage ratio from 19% to 7% and improved hydrophilicity which results in a solute rejection factor of 83% and 87% for Pb(II) and Cd(II), respectively, in comparison to other fabricated membranes. These membranes provide an economical and effective solution for wastewater treatment.

Graphical Abstract

Keywords:

• PVDF
• MMT
• mixed-matrix membranes
• filtration
• heavy metals

Acknowledgements

Authors are highly thankful to Quaid-i-Azam University, Islamabad, National Centre for Physics, Islamabad, and Pakistan Council of Research in Water Resources (PCRWR), Islamabad, Pakistan for providing the chemicals, laboratory facilities and characterization tools required for this project.

Authors’ contributions

Asima Siddiqa: Project administrator and methodology. Sabtain Haider: Data curation, investigation, writing original draft, review, and editing. Irum Abid: Methodology and writing the original draft. Saima Farooq: validation, review, and editing. Nisar Ahmed: Validation. Srosh Fazil: Supervision and validation. Sara Qaisar: Formal analysis and validation.

Disclosure statement

No potential conflict of interest was reported by the authors.