Preparation Of Heterogeneous Fenton Catalysts And Their Application In The Treatment Of The White Water Of Paper Machine

The pulp and paper industry produces a strongly colored effluent with high levels ofCODcr(Chemical Oxygen Demand) and suspended solids.This work explored the heterogeneous Fenton method to treat the white water of papermachine, the catalyst were prepared by loading Fe3+on active Al2O3and bamboo charcoal.The effects of quantity of H2O2, PH, concentration of catalyst impregnated, catalyst dosingquantity and reaction temperature on the white water cationic demand and CODcrremovalefficiency were studied. We can get the following main conclusions:(1)The optimal technological conditions: In the condition of20oC, carriers were added tothe Fe(NO3)3solution of fixed concentration. The shaking table speed was set as180rpm. After4h, the bamboo charcoal was filtered out, after treatment with enough sodium hydroxide thenwashed and dried; The active Al2O3were washed by distilled water until the washing liquorwithout Fe3+, and dried at105oC. The particle was baked for4h by the calcinationstemperature at550oC.(2)By the One-Factor-at-a-Time (OFAT) plan and orthogonal test, we got the optimumreaction conditions. With Fe2O3/Al2O3catalyst, at the conditions of40oC, pH=5,10g/Lcatalyst dosage which impregnation concentration was5%,0.3mL/L H2O2,56.29%cationicdemand and56.23%CODcrremoval could be achieved; With Fe(OH)3/bamboo charcoalcatalyst, the results showed that, the optimum condition were: under45oC, initial pH value1,catalyst dosage10g/L, and H2O2dosage0.5mL/L. At the optimum conditions, the CODcrandcationic demand remove rate53.68%and61.4%.(3) Catalysts were processed in two different ways to investigate the recycling times:1、catalysts were cleaned and dried after each experiment, then continue to put into using;2、continue with the experiment without any treatment. We can get the following conclusion: The Fe2O3/Al2O3catalyst still displayed good dyedecolorization performance after ten runs; thetreatment effect of Fe(OH)3/bamboo charcoal catalyst reduced significantly after three runs.This paper systemically analyzes the character of the white water in waste paper pulpingand papermaking industry, and the effects of technological factors on the white water treatmentresults by heterogeneous Fenton were studied. On basis of the above experiments, a rationaltreatment processes were established for improving the treatment results. This study providedtheory evidences and technical supports for the recycle of papermaking white water in pulp andpaper plants.