Enhanced Removal of p-Arsanilic Acid Using a Collagen Fiber-Derived Mg–Zn–Fe Metal Oxide Monolith

As an emerging micropollutant, p-arsanilic acid (p-ASA) would release highly toxic arsenate and arsenite during migration transformation. Herein, a three-dimensional polyethylenimine-aminated leather collagen fiber (CF-PEI) decorated with MgZnFe (MZF) metal oxides, i.e., CF-PEI@MZF monolith, was reported for the ultradeep p-ASA removal. The synergetic functions of hydrogen bonding and electrostatic interaction from the CF-PEI and coordinative interaction from the MZF on the monolith allow an ultrarapid kinetic that could achieve ca. 80% of the adsorption equilibrium within 20 min and a benchmarked exothermic Langmuir adsorption capacity as high as 588.24 mg g–1 for the p-ASA. It also performed an unparalleled feasibility in the continuous treatment to reduce the concentration of p-ASA to below 0.05 mg L–1 for real applications. We also highlight the monolith structure with great features of easy separation and recycling use for real industrial applications. All these demonstrate the merits of our CF-PEI@MZF monolith in addressing environmental engineering challenges.