Research On Mercury Removal By Hollow Fiber Membrane Reactor And Fenton Reagent

Mercury and its compounds had aroused the attention from the environmental protection departments since their extent of injury to human in recent years.In this paper,the properities,sources and related control technologies of mercury are introduced systematically.Compared with the adsorbent injection technology,the oxidation of mercury removal technology has a good prospect because it can avoid the follow-up treatment of adsorbent,mercury emissions and other issues.The oxidants used for mercury removal mainly are potassium permanganate,hypochlorite and potassium dichromate.However,these oxidants may need extra-treatment because new pollutions will be introduced to the system.Fenton reagent is a kind of green oxidant with strong oxidant ability,it has great potential in mercury removal even though it have not been widely used in practice.Hollow fiber membrane reactor has the advantages of convenient operation and large specific surface area so it has huge potential in gas treatment.In this paper,the mass transfer kinetics and reaction kinetics were studied by chemical absorption method in a hollow fiber membrane reactor.What's more,the process of mercury removal by Fenton reagent and the influence of impurity gas on mercury removal were systematically studied,too.The conclusions were as follow:1.In this paper,the specific phase area,the liquid film and the gas film mass transfer coefficient of the hollow fiber membrane reactor were calculated by chemical absorption method and getting their relationships about temperature and flow rate by nonlinear regression fitting.2.The kinetic parameters of H2O2 and Hg0 were measured on the basis of mass transfer kinetics.The reaction rate constant between H2O2 and Hg0 are 2.87×103m3/mol s and 5.71 ×103m3/mol.s under the condition of pH=2,T=298K and pH=2,T=308K,respectively.3.With the increase of H2O2 concentration,Fe2+ concentration,solution initial pH and temperature,the mercury removal efficiency will increase to and optimal value,and then decrease.The increase of liquid gas ratio is beneficial to the removal of Hg0,while the increase of gas flow rate is contrary.When the H2O2 concentration is 6mM,Fe2+concentration is 9mM,the initial pH of solution was 2.5,the temperature was about 20 ?,the liquid to gas ratio was 0.11 and the liquid flow rate was 0.6L/min,the removal efficiency of Hg0 is more than 85%.SO2 and NO inhibited the removal of Hg0 but O2 had no effect on the removal of Hg0.