043

Title:

Microwave-enhanced Membrane Filtration for degradation of PFASs

Discipline: environmental engineering

Presenter:

Fangzhou Liu

Abstract:

In recent years per- and poly fluorinated alkylated substances (PFASs) have been increasingly studied as a new class of global pollutants due to the broad historic uses in diverse industrial products. PFASs are extremely resistant to natural weathering and degradation processes such as hydrolysis, photolysis, and microbial degradation. Microwave-assisted membrane (MWM) filtration was explored to facilitate the degradation of refractory PFASs from wastewater. Microwave-absorbing catalyst (e.g., BiFeO3) coated on the ceramic membrane produced hydroxyl radicals that enhance oxidative degradation of PFASs (specifically PFOA as a model molecule). MW irradiation was selectively absorbed by catalysts and hydrogen peroxide to produce ‘‘hotpots” on membrane surface that promoted generation of nanobubbles, which prevented membrane fouling and assisted degradation of PFASs. The contributions from physical separation (size exclusion and sorption or chemical binding with ceramic membrane) and MW-Fenton-like degradation to the PFASs removal were analyzed and quantified by switching microwave irradiation “on” or “off”. Furthermore, the LC-QQQ mass spectrometry was used to identify degradation byproducts (e.g., PFPeA) and confirmed the transformation pathway of PFASs.

Author(s):

Fangzhou Liu

Funding Acknowledgements:

This research is supposed by a EPA SBIR Phase I project: Development of Microwave-assisted Membrane Filtration for Pretreatment of PFAS in Industrial Wastewater. Federal Contract #: 68HERD19C0014.