Elucidating the role of double-confined effect in hollow MOFs/GO catalytic membrane for deep arsenic pollution treatment

The significance of addressing arsenic contamination is huge, given its widespread environmental impact and detrimental effects on human health. Herein, we developed a double-confined catalytic membrane capable of activating peroxymonosulfate (PMS) by integrating hollow Prussian blue analogues (H-PBA) with a unique void-confinement effect into graphene oxide (GO) laminates. This delicately designed H-PBA/GO membrane displayed 98.8 % p-arsanilic acid (p-ASA) removal with a 9.03 s retention time, surpassing most reported studies. Our experiments underscored that the dual-confined architecture not only drove mass transfer but also bolstered reactant concentration, thereby multiplying catalytic activities. Remarkably, this double-confinement conduced to a sustained dominance of surface-radicals (SO₄[rad]⁻) and singlet oxygen (¹O₂), bolstering p-ASA degradation across a broad pH spectrum and numerous aqueous realms, inclusive of high salinity waters pertinent to desalination pre-treatment processes. Crucially, the H-PBA/GO membrane demonstrated over 90 % degradation of p-ASA and immobilized total As, unfaltering over 80 h of continuous operation. This signified an evolution in membrane technology, promising enhanced and steadfast performance. This innovation bore profound implications for devising double-confined efficacious and robust catalysts, poised to revolutionize advanced wastewater treatment, notably augmenting desalination systems by fortifying pre-treatment and safeguarding reverse osmosis membranes from organic and arsenic fouling.