How Dimensionally Stable Anodes(DSA) Performed in Phenol Degradation?

How Dimensionally Stable Anodes(DSA) Performed in Phenol Degradation?

Aqueous wastes containing aromatic compounds are recalcitrant and toxic towards the microorganism in conventional biological treatment reactions. Alternatives have been introduced for the destruction of toxic organic waste, including supercritical water oxidation, photochemical degradation, peroxide/UV, ozone oxidation, etc. Electrochemical degradation (ECD) is another alternative to the degradation method, which is suitable for low-volume application and environmental compatibility, and especially electrolysis can be used as a pre-treatment technology in detoxifying ahead of bio-treatment, rather than mineralizing them completely.

Although organic wastes, in general, can be oxidized at numerous electrode materials, an important factor for the application of electrochemical degradation is the anode materials and the electrolysis conditions, which can make toxic organic waste transfer to innocuous products with high current efficiency. High stability, high activity, and low cost are the desirable properties of electrodes. Poor current efficiency was usually found with the traditional electrodes, such as graphite and Ni. Toxic phenols can be oxidized rapidly at the Pt anode, but it is reported that phenols can cause the inactivation of Pt anode by the deposition of oligomers.

Dimensionally stable anodes (DSA) have been used in electrochemical applications recently. Application of electrodes based on RuO2 in chlorine-alkali cells and the mixed RuO2/IrO2 anode used for oxygen evolution in sulfuric acid media are two examples. DSAs are prepared by thermal deposition of a thin layer (a few micrometers) of metal oxides (RuO2, IrO2, SnO2, PbO2, etc) on a base metal, such as Ti,Ta, etc. 

Phenol can be electrochemically degraded on the surface of DSA anodes and Pt anodes. Phenol can be totally mineralized to CO2 and H2O on PbO2 anode. An interlayer of Sndoped SbO2 into Ti substrate and RuO2 coating in RuO2 base electrode can enhance the conductivity of the electrode and results in increasing catalytic characteristics.