Ternary metal composite membrane FCMNCM enhances the separation of As(III) in water through the multifunctional cooperation

More cases of arsenic contamination are reported globally, making the restoration of arsenic in water an active area of research. Especially, As(III) is more difficult to remove than negatively charged As(V) due to the presence of neutral H3AsO3 in the water, so to achieve efficient separation of As(III) in water, it is very important to pre-oxidize As(III) to As(V). Herein, Fe-coated Cu-0 doped MnO2 nanowire membrane (FCMNCM) was successfully prepared to enhance the oxidation of As(III) to As(V) through the combination of superoxide anion (O-2(center dot-)) and MnO2 oxidation. Experimental results show that Cu-0 activates oxygen to generate O-2(center dot-), the generated O(2)(center dot- )not only significantly enhances the conversion efficiency of As(III) to As(V) but also oxidize the Mn(II)/Mn(III) produced by the reduction of MnO2 by As(III) to Mn(IV) again to realize multi-channel oxidation of As(III), and the maximum separation efficiency of As(III) can reach 99.34%. Acidic conditions are favorable for the separation of As(III), and carbonate and phosphate have a serious negative effect on As(III) separation by competing for the active site. Anti-fouling and repeatability experimental show that FCMNCM is an environmentally friendly material with long service life and excellent reusability, it provides a new platform for As(III)-containing sewage treatment. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The restoration of arsenic in water is an active area of research globally, with pre-oxidation being a key step for efficient separation of As(III). The use of a novel material can achieve multi-channel oxidation to improve separation efficiency, while acidic conditions are favorable for separation. The study results provide a new solution for treating As(III)-containing sewage.