Colorimetric detection and membrane removal of arsenate by a multifunctional L-arginine modified FeOOH

Abstract

Arsenic pollution in water is endangering the environment safe and human health around the world. Thus, it is highly desirable to develop a new strategy to simultaneously detect and remove inorganic arsenic from polluted water. In this study, L-arginine modified FeOOH (2Arg@FeOOH) with perfect peroxidase-like activity to catalyze decomposition of H2O2 to generate hydroxyl radicals was firstly prepared, which is able to turn the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxidized TMB (TMBox). The catalytic active sites of 2Arg@FeOOH can be masked by As(V), resulting in inhibition of peroxidase-like activity of 2Arg@FeOOH. Based on this strategy, a visual quantitative detection platform towards As(V) was established, offering a wide detection ranging from 0.67 to 3333.33 µg L−1 and a low limitation of detection (LOD) of 0.42 µg L−1 (S/N = 3). Moreover, 2Arg@FeOOH was loaded on the fiber membrane (FM) to form 2Arg@FeOOH/FM, which was employed to remove As(V) from polluted water. The static and dynamic removal of As(V) by 2Arg@FeOOH/FM display that 2Arg@FeOOH/FM possesses excellent removal efficiency to As(V), and the maximum removal efficiency of 2Arg@FeOOH/FM towards As(V) reaches more than 95%. Meanwhile, 2Arg@FeOOH/FM exhibits excellent regeneration performance, remaining 76.1% removal efficiency after five cycles. In addition, 2Arg@FeOOH/FM have antibacterial activity, which is benefit for avoiding membrane contamination by bacteria. Thus, 2Arg@FeOOH has a promising application prospect for simultaneous colorimetric detection and membrane removal of As(V) from environmental water.