Elimination of methyl mercaptan in ZVI-S2O82− system activated with in-situ generated ferrous ions from zero valent iron

Abstract Activation of persulfate (PS) was conducted to oxidize methyl mercaptan (CH 3 SH) with in-situ generated ferrous ions from zero valent iron (ZVI) to generate sulfate free radicals (SO 4 − ) with high redox potential. The elimination of CH 3 SH by S 2 O 8 2− activated with ZVI was investigated through dynamic experiments. The effects of pH, inlet velocity, dosages of S 2 O 8 2− and molar ratio of S 2 O 8 2− /ZVI in the ZVI-S 2 O 8 2− system were examined. It is found that the complete CH 3 SH elimination can be achieved within the first 600 s in ZVI-S 2 O 8 2− system under optimal condition. The role of SO 4 − and OH in CH 3 SH elimination was determined and the mechanism of CH 3 SH elimination by ZVI-S 2 O 8 2− system was also examined through the identification of oxidation products and the mass balance of sulfur. In order to demonstrate the advantages of ZVI-S 2 O 8 2− system activated with in-situ generated ferrous ions from zero valent iron, the comparison experiment was conducted among using heat-S 2 O 8 2− system, Fe 2+ -S 2 O 8 2− system, and ZVI-S 2 O 8 2− system.