The Mechanism Research And Parameter Optimization Of Hg⁰ Removal Based On H₂O₂ Oxidation

Hg⁰,SO₂ and NO_x result in heavily global environmental pollution and serious health hazards.Up to now,the Hg⁰ removal technology is in urgent need to be optimized and how to efficiently remove mercury with SO₂ and NO_x from flue gas is still a tough task.In this study,series of high oxidizing Fenton systems were employed to purify the pollutants.The experimental results showed as follow:1)The optimal condition includes Fe³⁺concentration of 0.008 mol·L^-1,Hg⁰ inlet concentration of 40μg·m^-3,solution temperature of 50oC,pH of 3,H₂O₂ concentration of0.7 mol·L^-1 and O₂ percentage of 6%.2)When SO₂ and NO_x were taken into account under the optimal condition,Hg⁰removal efficiency could be enhanced.3)The removal of Hg⁰ with H₂O₂/Fe³⁺system was investigated and optimized by response surface analysis（RSM）in this study.Based on the results of single factor condition,Box-Behnken design（BBD）with three factors and levels was employed to investigate and used to analyze the interaction between solution temperature,H₂O₂concentration and Fe³⁺concentration on Hg⁰ removal.The experimental results showed that the optimal values for solution temperature,H₂O₂ concentration and Fe³⁺concentration were 51.78oC,0.55 mol·L^-1 and 0.0070 mol·L^-1 respectively,and 88.28%Hg⁰ removal efficiency was obtained under the optimum conditions.Meanwhile,the verifying experimental was proceeded under the optimal conditions,and it illustrated that as high as 89.23%±0.87%Hg⁰ removal efficiency could be obtained,and it was pretty in coincidence with the model predictive value.Thus the optimal parameters obtained from response surface methodology were accurate and reliable,and had directive significance for the conditions optimization of Hg⁰ removal with H₂O₂/Fe³⁺in the flue gas from steel industry.