Heterogeneous Fenton-like oxidative degradation of sulfanilamide catalyzed by RuO2-rectorite composite

RuO 2 -rectorite (RuO 2 -Rec) was prepared by intercalation, deposition and calcination. Its structure was characterized by XRD, XPS, SEM and EDS. It was used as a catalyst for the sulfanilamide (SA) degradation in the presence of H 2 O 2 . Unlike sodium-rectorite and RuO 2 which couldn’t catalyze the degradation of SA, RuO 2 -Rec could effectively catalyze the decomposition of H 2 O 2 into hydroxyl radicals to degrade SA. The degradation rate could reach ~ 100% under the optimal conditions of 58 μmol/L of SA, 1.16 mmol/L of H 2 O 2 , 0.133 g/L of RuO 2 -Rec, pH 3.5 and 25 °C in 5 h. The degradation process conformed to pseudo-first-order kinetic correlation. This degradation was affected by pH, the amount of RuO 2 -Rec and the concentrations of H 2 O 2 and SA. However, under the optimal pH value of 3.5, a high degradation rate could be achieved with the increase in SA concentration from 58 μmol/L to 290 μmol/L as long as the optimal ratio of RuO 2 -Rec, H 2 O 2 and SA kept unchanged. In addition, RuO 2 -Rec was stable and possessed low ruthenium leaching rate and excellent reusability. Therefore, RuO 2 -Rec is expected to be an active catalyst for the pollutant removal in the heterogeneous Fenton-like system.