Degradation of an Organic Dye by Bisulfite Catalytically Activated with Iron Manganese Oxides: The Role of Superoxide Radicals

Abstract

Metal-activated bisulfite systems have been widely used to treat recalcitrant wastewater. However, due to the disadvantages of their narrow effective pH range and difficulty in recovering metal ions, homogeneous systems are severely limited in practical applications. To overcome these problems, Fe/Mn bimetallic catalysts with different molar ratios were prepared using a simple sol–gel method to activate bisulfite. Influential factors, such as catalyst and system types, catalyst dosage, bisulfite concentration, pH value, and bisulfite addition modes, were investigated. The new system exhibited a wide effective pH range and high degradation efficiency, and it was found that the dissolved oxygen content played an important role in the activation system. The radical quenching test showed that a superoxide radical (O 2 •– ), instead of a hydroxyl radical (HO • ) or a sulfate radical (SO 4 •– ), was the main oxide species for the degradation of rhodamine B (RhB).

Vicinal halo-trifluoromethylation of alkenes

“…Finally, it should be noted that transition metal complexes play important role in halo-triuoromethylation of alkenes and other compounds. [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65]…”

Hydroxysulfonylation of alkenes: an update

“…Finally, it should be noted that transition metal complexes play important role in the hydroxysulfonylation of alkenes and other compounds. [35][36][37][38][39][40][41][42] 9. Conclusion b-Hydroxysulfones are valuable skeletons found in many biologically active molecules, and provide useful building blocks in organic synthesis.…”

Transition‐metal‐catalyzed dehydrogenative coupling of alcohols and amines: A novel and atom‐economical access to amides

“…Finally, it should be noted that transition metal complexes play an important role in synthesis of alcohols, amines, and other compounds. [ 63–89 ]…”