Adsorbent nanoarchitectonics of mMnO2/nFeOOH/KIT-6 for As(iii) adsorption from wastewater

A manganese dioxide and ferric hydroxide doped KIT-6 adsorbent (8MnO2/FeOOH/KIT-6) was prepared and employed for As(iii) adsorption. The studies indicated that the large surface area, particular pore structure and the synergy interaction between FeOOH and MnO2 endow the adsorbent with excellent adsorption performance. The adsorption rate of 8MnO2/FeOOH/KIT-6 for As(iii) could reach 92% when the As(iii) initial concentration was 20 mg L−1 and the adsorbent dose was 1 g L−1, at pH 1. During five consecutive cycles, 8MnO2/FeOOH/KIT-6 exhibited good stability, and the adsorption rate was consistently above 90%. The adsorption capacity of the 8MnO2/FeOOH/KIT-6 for As(iii) was 39.77 mg g−1 when 10 mg of adsorbent and 10 mL of As(iii) ion solution (20 mg L−1) were used at pH 1 and 303 K. The adsorption of As(iii) on 8MnO2/FeOOH/KIT-6 was a spontaneous process and in line with the pseudo-second-order kinetic model. More importantly, 8MnO2/FeOOH/KIT-6 showed excellent selectivity in a complex system, for example Cl−, NO3−, SO42−, SiO32− or Ge4+ coexisting with As(iii) in wastewater.