Membrane anodic Fenton treatment

Wang Q, EM Scherer, AT Lemley (2004) Metribuzin degradation by membrane anodic Fenton treatment and its interaction with ferric iron. Environ Sci Technol 38 1221-1227. 

Wang, Q. and Lemley, A. T. (2003) Oxidative degradation and detoxification of aqueous carbofiiran by membrane anodic Fenton treatment. J. Hazard. Mater. B98, 241-255. 

Figure 6. Membrane anodic Fenton treatment appartus. (1) Anodic halfcell (2) Cadiodic half-cell (3) Ion exchange monbrane (4) Iron plate (S) Graphite stick (6) Magnetic stirring plate...

This section is devoted to discuss the main results obtained for the treatment of organics in wastewaters by electro-Fenton using a divided cell usually with a cationic membrane (e.g., of Nation) to separate the anolyte and catholyte. Although the anode reactions do not affect the degradation of pollutants under these conditions, it is interesting to know the characteristics of their homogeneous oxidation with OH when this radical is uniquely formed in the medium from Fenton s reaction (19.12). 

In contrast, in the cation membrane AFT system, the membrane only allows anodic Na and H to pass through to the cathodic half-cell. With an increase of cathodic NaCl concentration, the movement of Na firom anode to cadiode may become more difficult because of die concentration gradient between the two half-cells. More H" than Na may move into the cathodic half-cell. To regenerate H and keep the optimal pH for the Fenton reaction, some of the Fenton reagent may be consumed. This can result in a decrease of treatment efficiency in the cation membrane AFT system when the NaCl concentration ratio (cathode/anode) is high. The functional stebility of the membrane was also evaluated in this study, and it was found that treatment efficiency for degradation of carbaryl did not change after the membrane was used 100 times. 

---