Construction Of Fenton System With High Fe(Ⅱ) Concentration And Study On Enhancing Degradation Performance Of Rhodamine B

With the increasing awareness of environmental protection,the national standard of discharge water quality is becoming more and more strict,it’s urgent to popularize advanced wastewater treatment technology in various industries.Fenton oxidation process with many advantages has been widely used in wastewater treatment,but it still exists some problems,such as lower pH condition,and large amount of iron mud produced and so on.Aiming at the defects existing in traditional Fenton system,this paper explored the role of reductant Cysteine(Cys)in promoting Fe3+/Fe2+ cycle,enhancing catalytic oxidation activity of Fenton system.The experiment used Rhodamine B(RhB)as substrate,found that RhB degradation efficiency was clearly improved by introducing Cys to Fenton system,and the optimal reaction conditions for RhB oxidation degradation by Fenton/Cys were H2O2 concentration 1.0 mM,Fe2+ concentration 0.1 mM,Cys concentration 0.1 mM,pH 4.0.Fe3/Cys,H2O2/Fe2+Cys blank systems and Fenton/Cys degrading glycerol system were used to verify the effect of Cys on promoting Fe3+/Fe2+ redox cycle,found that in Fe3+/Cys system with pH 4.0,Cys reducd Fe3+ to the best,· OH production in H2O2/Fe2+/Cys system was 1.65 times as much as that in H2O2/Fe2+ system at 20 min.In Fenton/Cys degrading glycerol system with pH 5.0,both Fe2+ concentration and H2O2 utilization rate reached the maximum.Fenton/cys system existed in Cysteine/Cystine and Fe3+/Fe2+two groups of redox cycles.Exploring the role of dissolved oxygen in Fenton system,this study found that RhB degradation efficiencies in Fenton/02 system under different COD/H202 ratios were lower than those in Fenton/without O2 system.At COD/H202 10,difference of RhB degradation efficiencies between two systems was the largest.At this ratio,RhB degradation efficiency and H2O2 utilization rate in Fenton/without 02 system were respectively 32.6%,53.8%higher at 20 min,OH concentration was about 1.5 times higher at 10 min than those in Fenton/O2 system.This indicated dissolved oxygen had a negative effect on RhB degradation in Fenton system.Besides,dissolved oxygen also exerted a negative effect on RhB degradation in Fenton/Cys system and the higher content of dissolved oxygen,the greater negative effect.