Biochar-based asymmetric membrane for selective removal and oxidation of hydrophobic organic pollutants.

Hydrophobic organic pollutants (HOCs) in the complex groundwater and soil pose serious technical challenges for sustainable remediation. Herein, an asymmetric membrane (PCAM), inspired by the plant cuticle, was comprised of a top polydimethylsiloxane layer being selectively penetrable to HOCs from complex solution with humic acid, followed by transfer and catalyst layers with biochar pyrolyzed by 300 °C (BC300) and 700 °C (BC700). The PCAM triggered the advanced oxidation of the coming pollutant. The graphitized biochar layer of the PCAM acted as catalysts that induced HOC removal through a non-radical oxidation pathway. Compared to one type biochar membrane, the sequential multi-biochar composite membrane had a faster removal efficiency. The greater uptake and transport performance of multi-biochar composite membrane could be due to the larger pore size and distribution properties of PCAM physicochemical properties and oxidative degradation of peroxymonosulfate. The developed PCAM technology benefits from selective adsorption and catalytic oxidation and has the potential to be applied in complex environmental restoration. [Display omitted] • A selective layer of PCAM was permeable to organics rather than humic acid and water. • A transfer layer of PCAM supported the selective layer and quickly adsorbed HOC. • A catalytic layer of PCAM was beneficial to a high mass transfer flux and activated oxidant. • The PCAM and oxidation degradation favor superior removal of HOCs in complex system. [ABSTRACT FROM AUTHOR]