The Study On Rhodamineb Degradation Of Catalyzing Fe?0? And FeSO₄ To Reduct By Bio-Pd/Fe₃O₄ Microorganism-synthesized

With the continuous development of industry,dye wastewater has been caused to the serious environment problem.Rhodamine B is a kind of typical oxygen mixed anthracene alkaline dye.In recent years,the treatment of wastewater containing rhodamine B is particularly prominent,there is the main method of degradation of rhodamine B:photocatalytic degradation,ultrasonic chemical method,fenton reagent degradation,etc.But the method of reduction is still very rare.In this paper,Shewanella oneidensis,Pd?II?and magnetic nanometer Fe₃O₄ were used to synthesize bionano catalyst Bio-Pd/Fe3O4,and the reduction of RhB was catalyzed by zero-valent iron Fe?0?and ferrous sulfate?FeSO₄?respectively.The effects of the pH,Bio-Pd/Fe3O4 concentration,the initial concentration of RhB,Fe?0?and FeSO4 adding the quantity on the RhB removal process were studied,and a new method for degradation of RhB was explored.When Fe?0?was used as reducing agent,RhB experimental results of catalytic reduction reaction were as follows:Bio-Pd/Fe3O4 had a strong catalytic effect.The final removal rate of RhB is affected by the pH,the concentration of Bio-Pd/Fe3O4,the initial concentration of RhB and Fe?0?adding the quantity.The maximum removal rate of RhB in single factor experiment was 92.43%.The optimal reaction conditions of the orthogonal experiment is:The initial concentration of RhB is 8mg/L,Bio-Pd/Fe3O4concentrations is 300mg/L,pH=3,and Fe?0?adding the quantity is 40mg.The order of influence of each factor were obtained:Bio-Pd/Fe₃O₄ concentrations>the initial concentration of RhB>Fe?0?adding the quantity>pH.Under optimal conditions,the high removal rate is achieved and reductant dosage can be reduced.In the case of different pH,different Bio-Pd/Fe3O4 concentrations and different Fe?0?adding the quantity,the degradation process of RhB was first order reaction.The maximum value of the rate constant K is:pH=3;The concentration of Bio-Pd/Fe3O4=300mg/L;Fe?0?adding the quantity is 50mg.When FeSO₄ was used as reducing agent,RhB experimental results of catalytic reduction reaction were as follows:Bio-Pd/Fe3O4 also had a strong catalytic effect.the pH,the concentration of Bio-Pd/Fe3O4,the initial concentration of RhB and FeSO4adding the quantity will affect the removal rate of RhB.The maximum removal rate of RhB in single factor experiment was 85.88%.The optimal reaction conditions of the orthogonal experiment is:The initial concentration of RhB is 12mg/L,Bio-Pd/Fe₃O₄concentrations is 300mg/L,pH=6,and FeSO4 adding the quantity is 40mg.The order of influence of each factor were obtained:FeSO4 adding the quantity>initial concentration of RhB>pH>Bio-Pd/Fe3O4 concentrations.Under optimal conditions,the removal rate of RhB was 81.44%after 120min,which was close to the highest removal rate of single factor experiment.In the case of different factors,the degradation process of RhB is a first-order reaction.In the process of increasing pH and Bio-Pd/Fe3O4 concentration,the overall performance of the reaction constant K was firstly increased and then decreased.In the process of increasing the FeSO₄ adding the quantity,the reaction constant K generally shows which is going to increase gradually and then stabilize.