High-performance catalytic ultrafiltration membrane for peroxymonosulfate activation: The utility of high-valence metal species and enhanced mass transfer

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Persulfate-based oxidation is effective for pollutant degradation but limited by mass transfer.
• Developing advanced materials is crucial to overcome these limitations in water treatment.

Purpose of the Study:

• To fabricate and optimize a spinel-incorporated catalytic poly(vinylidene fluoride) membrane (spinel-PVDF).
• To investigate the catalytic mechanism and assess the performance of the spinel-PVDF membrane in pollutant degradation.

Main Methods:

• Fabrication of spinel-PVDF composite membrane.
• Molecular dynamics simulations to understand catalytic mechanisms.
• Batch experiments to evaluate pollutant degradation efficiency, kinetics, and stability.
• Analysis of active species using experimental evidence.

Main Results:

• The spinel-PVDF membrane achieved a high pseudo-first-order reaction kinetics constant (k_m) of 1256.47 min^-1.
• Demonstrated broad pH tolerance (3-12) and resistance to humic acid and anions.
• Effective degradation of various pollutants, especially electron-rich compounds.
• High stability with >95% degradation efficiency maintained for 120 hours at 100 LMH flux.

Conclusions:

• The spinel-PVDF membrane significantly enhances catalytic efficiency in persulfate-based water treatment.
• The membrane exhibits robust performance, stability, and broad applicability for wastewater treatment.
• High-valent metal species and singlet oxygen are key active agents in the degradation process.