In-situ production and activation of H2O2 for enhanced degradation of roxarsone by FeS2 decorated resorcinol-formaldehyde resins

Fenton technology performs well in high-risk roxarsone (ROX) removal, but it is limited by the high H 2 O 2 transportation and storage risks. Herein, FeS 2 decorated resorcinol-formaldehyde resins (FeS 2 -RFR) were successfully prepared to in-situ produce and utilize H 2 O 2 for efficient removal of ROX. Under solar light illumination, resorcinol-formaldehyde resins (RFR) efficiently generated a high concentration of H 2 O 2 , with a yield of 500 μmol g −1 h −1 . FeS 2 can in-situ decompose H 2 O 2 to generate · OH, participating in the oxidation of ROX. As a result, the FeS 2 -RFR catalyst degraded more than 97% of ROX within 2 h and ROX was selectively degraded into low-toxic As(V), which can be simply removed by traditional adsorption or precipitation processes. During the degradation of ROX, · OH played a dominant role. Moreover, the cations (Na + , K + , and Ca 2+ ), anions (SO 4 2− , Cl − ), and humic acid had no noticeable inhibition effect on ROX removal. Furthermore, FeS 2 -RFR can still remove 70% of ROX even after three cycles, proving that this in-situ photo-Fenton system exhibited stability. This study innovatively proposed a double-active site FeS 2 -RFR photocatalyst for in-situ production and activation of H 2 O 2 and showed a sustainable and eco-friendly way for organoarsenic compounds degradation.