The coupling use of electro-chemical and advanced oxidation to enhance the gaseous elemental mercury removal in flue gas

A novel diffusion electro-chemical combined advanced oxidation reactor offers potential for elemental mercury (Hg-0) removal in flue gas and shown excellent performance. This study introduced an ultraviolet light into the electric catalytic system to form an UV-electric oxidation system to strengthen Hg-0 removal. Hg-0 removal efficiency in the combined UV-electric oxidation system reached up to 65%. Hg-0 is excited by UV lamp with a wavelength of 253.7 nm, and a very small amount of oxygen contained in high-purity nitrogen can still participate in Hg-0 oxidation reaction. In addition, the Fenton method has also been introduced into the simple electrolysis system. Both the above combined system can improve the efficiency of Hg-0 removal. The electrochemical GDE was characterized by SEM, BET, and contact angle and gas permeability. The electro-chemical and advanced oxidation process (Fenton method and UV illumination) combined within a system or individually in series were explored the different influencing factors. The gaseous elemental mercury removal mechanism of the combined electro-chemical and advanced oxidation was investigated via combining the experimental data and theoretical reasoning. Electrochemical coupling with other advanced oxidation technologies is a promising technology.

Automated summary

The introduction of UV in the electric catalytic system improved the efficiency of Hg-0 removal in flue gas. The combined electro-chemical and advanced oxidation technologies show promise in gaseous elemental mercury removal.