Effectively remove p-arsanilic acid from water over amphiphilic amino modified collagen fiber

Abstract

Efficient and rapid removal of p-arsanilic acid (p-ASA) in water is very important in environmental protection and human health, however it is still a severe challenge in actual engineering. Herein, a novel sorbent (CF-PEI) was successfully fabricated by simply modifying the amphiphilic skin collagen fiber (CF) substrate with Polyethylenimine (PEI). The as-prepared CF-PEI exhibits high-efficiency adsorption for negatively charged p-ASA with aromatic rings due to the introduction of amino groups and the existence of hydrophobic bands, and the maximum adsorption capacity of CF-PEI for p-ASA was high up to 285.71 mg g^-1. In addition, the adsorption mechanism of CF-PEI on p-ASA mainly includes electrostatic interaction, hydrogen bond and amphiphilicity. The multi-level all-fiber structure of CF makes it mainly focus on surface mass transfer with short mass transfer distance, and its capillary drainage effect can realize large flow and rapid separation. CF-PEI based on CF can realize the ability to separate low-concentration p-ASA with high flow rate and high efficiency. The effective processing volume was 12.5 L g^-1 when the separation flux reached as high as 9931.27 L m^-2 h^-1. Notably, the p-ASA adsorbed on CF-PEI was almost completely eluted by NaOH (0.5 mol L^-1). The adsorbent is convenient to prepare, recyclable, high in efficiency, and has a great application prospect in removing organic micro-pollutants.

Keywords: Amphiphilicity; Capillary drainage; Collagen fiber; Continuous separation; p-arsanilic acid.