Removal of Elemental Mercury by Sodium Chlorite Solution

The important step for increasing gaseous elemental mercury (Hg⁰) removal in wet scrubber systems is altering the chemical form of the Hg⁰ to a water‐soluble oxidized species. This work focuses on the removal of elemental mercury from simulated flue gas by aqueous sodium chlorite in a bubble reactor. The effects of initial oxidizing solution concentration, reaction temperature, pH and mercury concentration in the inlet of the reactor on mercury oxidative absorption in sodium chlorite were investigated. The results indicate that higher concentrations of sodium chlorite favor Hg⁰ removal, with a greater efficiency observed in acidic than in alkaline solution. High temperature inhibits Hg⁰ absorption in aqueous sorbent when the reaction temperature is lower than ca. 40 °C, and the removal efficiency increases when the temperature is higher than that value. In conclusion, the major influencing factors on the levels of Hg⁰ removal are pH and chlorite concentration in solution.