【摘要】 基于鼓泡塔反应器,研究了WFGD系统中Hg⁰再释放特性,并探索了芬顿（Fenton）试剂抑制Hg⁰再释放的效果及机理。结果表明:还原性离子SO₃^2-、HSO₃^-是引起Hg⁰再释放的主要原因。单独添加H₂O₂对Hg⁰再释放的抑制效果较差,但同时添加H₂O₂和Fe³⁺、Fe²⁺、Cu²⁺等金属离子时可有效抑制Hg⁰再释放,其抑制效果为Fe²⁺>Fe³⁺>Cu²⁺。芬顿试剂抑制Hg⁰再释放主要是由于氧化性基团OH·和OOH·可将Hg⁰氧化成Hg²⁺。添加Fe²⁺-Fenton试剂时,当脱硫液pH值为3.0～4.0,脱硫液温度为50℃左右,烟气温度为120℃左右时,WFGD系统脱汞性能较好;增大Fe²⁺浓度有利于提高脱汞效率,但当Fe²⁺浓度>5×10^-5后,脱汞效率几乎不再受Fe²⁺浓度影响。更多还原

【Abstract】 In order to inhibit the re-emission of Hg⁰ in the WFGD system and improve the mercury removal efficiency, the re-emission characteristics of Hg⁰ in the WFGD system based on the bubbler reactor were studied, and the inhibiting effect of Fenton reagent on the re-emission of Hg⁰ and its inhibiting mechanism were explored. The results show that the reduction of Hg²⁺by SO₃^2- and HSO₃^- in desulfurization solution is the main cause of Hg⁰ re-emission. H₂O₂ had a poor inhibiting effect on Hg⁰ re-emission, but the addition of H₂O₂ together with metal ions such as Fe³⁺, Fe²⁺and Cu²⁺can effectively inhibit the re-emission of Hg⁰, and inhibitory effect is Fe²⁺> Fe³⁺> Cu²⁺. The main reason of Fenton reagent inhibiting Hg⁰ re-emission is that oxidizing groups OH·and OOH·can oxidize Hg⁰ to Hg²⁺. When adding Fe²⁺-Fenton reagent: pH value of the desulfurization solution is in the range of 3.0 ～ 4.0, desulfurization liquid temperature is about 50 ℃, flue gas temperature is 120 ℃, the mercury removal efficiency of WFGD system is the best. Increasing the concentration of Fe²⁺is conducive to improve the efficiency of mercury removal. However, when the concentration of Fe²⁺is greater than 5×10^-5,the efficiency of mercury removal is hardly influenced by the concentration of Fe²⁺.更多还原