Removal of Hg⁰ from Simulated Flue Gas by Fenton Process in A Hollow Fiber Reactor

A novel hollow fiber reactor was used to remove Hg⁰ from simulated flue gas by Fenton process.The effects of several parameters and impurity gases such as SO₂、NO and O₂ on removal efficiency of Hg⁰ by Fenton process were investigated.The results indicated that the Hg⁰ removal efficiency increased first and then decreased upon increasing H₂O₂ concentration,Fe²⁺ concentration,initial pH value of solution,and temperature.The optimum conditions were:H₂O₂ concentration of 6 mmol/L, Fe²⁺ concentration of 9 mmol/L,initial pH value of solution of 2.5, and temperature of 20℃.The increase in liquid-gas ratio and the residence time (the decrease of gas flow rate) enhanced the removal of Hg⁰,while the removal efficiency didn't increase any more when the liquid-gas ratio was over 0.11.Hg⁰ removal efficiency exceeded 85% when gas flow rate was 0.6 L/min.SO₂ and NO can inhibit the removal of Hg⁰, while O₂ has no obvious impact on Hg⁰ removal efficiency.In the hollow fiber reactor,the specific surface area (a) and mass transfer-reaction coefficient (k_L,k_G) between Fenton reagent and Hg⁰ were 270.29 m^-1,8.13×10^-4 m/s,0.786×10^-6 mol/(m²·s·Pa) (20℃),respectively.