Weakly hydrophobic microenvironment-assisted membrane-based confined catalysis for efficient organoarsenic contamination removal

Enhancing the peroxymonosulfate (PMS) activation in powder Fe-based metal-organic frameworks (MOFs) for addressing insufficient mass transfer and reactivity loss in humid environments remains a significant challenge. In response to this issue, we proposed a novel approach involving the creation of a weakly hydrophobic microenvironment-assisted confined strategy for the fabrication of a mixed dimensional GO-HT@ bimetallic Prussian blue analogues (PBA) confined catalytic membrane through low-temperature treatment (GO-HT). This innovative method has demonstrated improved mass transfer capabilities for the safe treatment of organoarsenic compounds. The optimized GO-HT@PBA confined membrane exhibited a marked improvement in the removal efficiency of p-arsanilic acid (p-ASA) compared to its unconfined counterpart, showing a substantial increase in the reaction kinetic constant by 6-7 orders of magnitude (0.46 ms-1) compared to unconfined GO-HT@PBA/ PMS system. Additionally, the GO-HT@PBA membrane exhibited superior pH tolerance, and resistance to inorganic ions, humic acid, and complex water matrices. Notably, the membrane achieved nearly complete degradation of p-ASA and immobilization of total arsenic over a continuous operation period of 107 h, highlighting its exceptional reactivity and stability. Overall, our research will inform the development of MOF-based composites, with the potential to enhance the reactivity of the catalytic component and mitigate its inherent limitations by leveraging the host's properties.