Fast and almost 100 % of roxarsone conversion to As(V) on CoFe2O4/peracetic acid system

The increased discharge of organoarsenic to natural waters, brings significant risks to ecosystems and human health. It is curial to rapidly transform organoarsenic to harmless arsenate (As(V)) before conventional coagulation-sedimentation treatment. In this study, the roxarsone (ROX) was destroyed to form As(V) with almost 100 % transformation rate and reaction rate of 0.43 min−1 via the CoFe2O4/peracetic acid (PAA) system. Specifically, PAA was primarily activated to form singlet oxygen (1O2) and organic radicals (R-O·) by Co(II)/Co(III) redox cycle existed on the CoFe2O4 surface, the presence of iron (Fe) in the CoFe2O4 facilitated the transformation of Co(III) to Co(II), and then that reactive oxygen species (ROS) was employed to mineralize ROX. The presence of common anions, and natural organic matters (NOM) hardly inhibit the degradation of ROX. Furthermore, the catalytic efficiency of CoFe2O4/PAA system remained above 94 % after five cycles. These findings suggest that the CoFe2O4/PAA system is a promising technique for enhanced arsenic decontamination. [Display omitted] •CoFe2O4 enhanced peracetic acid activation to remove roxarsone.•The removal kinetic of roxarsone reached 0.43 min−1 by CoFe2O4/ peracetic acid system.•Singlet oxygen played a predominant role in roxarsone degradation.