Versatile dodecyl trimethyl ammonium bromide modified γ-FeOOH for simultaneous removal and determination of As(⠤).

ABSTRACT

Inorganic arsenic pollution in water spreads all over the world, tremendously threatening environmental safety and human health. Herein, versatile dodecyl trimethyl ammonium bromide modified γ-FeOOH (DTAB-γ-FeOOH) was prepared for sportive removal and visual determination of As(Ⅴ) in water. DTAB-γ-FeOOH displays a nanosheet-like structure with a high specific surface area calculated as 166.88 m2 g-1. Additionally, DTAB-γ-FeOOH shows peroxidase-mimicking feature, which can catalyze colorless TMB to generate blue oxidized TMB (TMBox) in presence of H2O2. Removal experiments show that DTAB-γ-FeOOH exhibits good As(Ⅴ) removal efficiency because modification of DTAB makes γ-FeOOH carry abundant positive charges, improving affinity between DTAB-γ-FeOOH and As(Ⅴ). It is found that theoretical maximum adsorption capacity is up to 126.91 mg g-1. Moreover, DTAB-γ-FeOOH can resist interference of most of co-existing ions. After that, As(Ⅴ) was detected based on peroxidase-like DTAB-γ-FeOOH. As(Ⅴ) can be adsorbed onto DTAB-γ-FeOOH surface, markedly inhibiting its peroxidase-like activity. Based on it, As(Ⅴ) ranging from 1.67 to 3333.33 µg L-1 can be well detected, with a low LOD (0.84 µg L-1). The successful sorptive removal and visual determination of As(Ⅴ) from real environmental water indicated that DTAB-γ-FeOOH has great potential in the treatment of As(Ⅴ)-containing environment water.