Study On The Degradation Of Reactive Brilliant Blue Wastewater By Goethite Fenton-like System

The discharge of dye wastewater with great quantity has caused serious environmental pollution.With the promulgation and implementation of the ?discharge Standard of Water pollutants for dyeing and finishing of textile Industry?,the discharge requirements of dye wastewater are more stringent.As an important reactive dye,reactive brilliant blue K-GR is widely used in various dyeing industries.Active brilliant blue wastewater has the characteristics of high chroma,complex composition,high organic matter content and poor biodegradability.It is difficult to meet the discharge standard by traditional treatment method.It is one of the internationally recognized industrial wastewater that is difficult to degrade.As a new technology of wastewater treatment,advanced oxidation process has been widely used because of its advantages of fast reaction,low selectivity and good treatment effect.Because of its strong oxidizing properties,Fenton reagent method is especially suitable for industrial wastewater which is difficult to biodegrade,so it has become a common method for wastewater treatment.However,the Fenton reagent method has some shortcomings,such as the narrow range of pH value,difficulty in reclaim of catalyst,which seriously affects the popularization and application of the technology.But after continuous efforts to study,Fenton-like technology began to come into being,and has made a major breakthrough.In this paper,Fenton reagent method and goethite Fenton-like reagent method were used to study the efficiency of simulated reactive brilliant blue(K-GR)wastewater treatment.Firstly,the active brilliant blue wastewater was treated by Fenton reagent method,and the main factors of the treatment effect were studied by single factor analysis method.At the same time,the influence of common inorganic anions on the treatment efficiency of dye wastewater was investigated.According to the design principle of Box-Benhnken,the experimental parameters were designed.The factors and interactions were studied by response surface methodology and the degradation rate of reactive brilliant blue K-GR was optimized.The results show that in many factors,the pH value affect the treatment significantly;inorganic salt anion has inhibitory effect on ability of Fenton reagent,size: H2PO4->S2->Cl-;H2O2 and Fe SO4 dosage and the degradation rate had significant correlation,the best reaction conditions after correction for: pH=2.8,hydrogen peroxide concentration was 3.7mmol/l,the concentration of ferrous sulfate was 0.75mmol/l,.Under this optimal condition,the average decolorization rate is 98.5%.Secondly,in this experiment,synthetic goethite(?-FeOOH)was used as a catalyst to construct an heterogeneous Fenton-like system to degrade reactive brilliant blue wastewater.The effects of reaction time,catalyst dosage,H2O2 concentration and initial pH value on the treatment efficiency were studied by single factor experiment.The optimal reaction conditions were obtained by optimizing the treatment effect of goethite Fenton-like method by response surface methodology.The experimental results show that the iron ore Fenton-like reagent method has a good effect on the treatment of reactive brilliant blue wastewater,and the response surface experimental data are fitted by software Design-expert 8.0,and the mathematical model of the decolorization rate of reactive brilliant blue K-GR is established.The model determination coefficient R2=0.9984 shows that the model correlation and reliability are better.The initial pH value,hydrogen peroxide concentration and goethite dosage is not a simple linear relationship.Through parameter optimization,the best operation parameters are as follows: initial pH=3.13.concentration of H2O2 2.92mmol/l and dosage of goethite 0.67g/l.Finally,in order to better understand the degradation of reactive brilliant blue wastewater by goethite Fenton-like system,the kinetics of degradation of active brilliant blue in goethite Fenton system was studied.The effects of the initial concentration of reactive brilliant blue,the amount of catalyst and the concentration of H2O2 on the degradation rate of active brilliant blue in goethite Fenton-like system were investigated and the kinetic model equation was deduced.The experimental results show that the first-order reaction kinetics can better describe the system,and the parameters of the kinetic model can be calculated by measuring the concentration changing regulation of reactive brilliant blue at different times in the reaction process.Thus the kinetic model equation for the treatment of reactive brilliant blue wastewater by Fenton-like oxidation of goethite is obtained.