Experimental Study On The Treatment Of Printing And Dyeing Wastewater Using Ultrasonic Coupling With Fenton

The printing and dyeing wastewater emissions of our coutry are large, it has highchromaticity and complex ingredients, which pollutes the environment heavily, and itbecomes an environmental problem of interest to the people. Using Fenton reagent totreat printing and dyeing wastewater yields results, but Fenton reagent has someshortcomings, such as easy to form precipitations, narrow pH applicable scope, etc.Effects of Fenton reagent treatment of printing and dyeing wastewater has been made,ultrasound technology has fast response speed, wide applicable scope, but it is also notperfect. In recent years, scholars at home and abroad use ultrasonic technology withFenton method to deal with a variety of wastewater and make progress, but the processconditions are not perfect.Ultrasonic technology is combined with Fenton method to treat printing anddyeing wastewater, using Fenton method only, ultrasonic technology only,ultrasonic technology with homogeneous Fenton method, ultrasonic technology with heterogeneous Fenton method, to study COD and chroma removal rate of printing and dyeing wastewater, and study the dynamics of heterogeneous Fenton, theexperimental results show:Separately using Fenton reagent to deal with printing and dyeing wastewater, theresults show that, the main factors influencing the removal rate are the addition of H2O2,the addition of FeSO47H2O, reaction time, pH, and the optimal reaction conditions are:the addition of FeSO47H2O is0.8g, the addition of H2O2is5mL, reaction time is45min, pH value is3.Separately using ultrasonic technology to treat printing and dyeing wastewater, theresults tell that, the main factors influencing the removal rate are pH value, ultrasonictime, ultrasonic power, the optimal reaction conditions are as follows: the ultrasonictime is3h, ultrasonic power is120W, pH value is8.Using Fenton reagent combined with ultrasonic to treat printing and dyeingwastewater, experiments about single factor show that, ultrasonic has certain reinforcement on Fenton reagent. The best level combination of orthogonal experimentsare: pH value is3, reaction time is1.5h, the addition of H2O2is4.5mL, the addition ofFeSO47H2O is0.7g, ultrasonic power is142.5W. When the parameters are in the firstplace, the removal rate of COD and chroma are respectively as high as94.8%and87.1%.The effects of baking time, roasting temperature and the types of iron salts oncatalyst performance are examined, nine heterogeneous Fenton catalysts are prepared indifferent roasting time and roasting temperature, using heterogeneous Fenton catalystswith orthogonal test to remove COD and chroma of printing and dyeing wastewater, tostudy printing and dyeing wastewater using ultrasonic combined with Fenton reagent.The results show that, the solution of0.5mol/L FeSO4is the optimal impregnationliquid, the best roasting temperature is400℃, the best roasting time is4h, catalystsmade in this condition have the best removal rate of printing and dyeing wastewater,and the best parameters are: ultrasonic time is2.5h, the addition of H2O2is5.5mL, theaddition of heterogeneous Fenton catalyst is1g, ultrasound power is135W. Whenparameters are best, the removal rate of COD and chroma are respectively as high as95.8%and88.5%.Catalysts are characterized, the SEM results show that, activated carbon has verygood adhesion effect on iron ion. Besides, mass spectrometry analysis tells, catalystshave high iron ion and some impurities on them. Contrast test results of homogeneousand heterogeneous Fenton to treat printing and dyeing wastewater show, heterogeneousFenton has a wider range of application than homogeneous Fenton.The heterogeneous Fenton reaction kinetics are studied, the results tell,heterogeneous Fenton system of the degradation of printing and dyeing wastewaterconforms to a first-order reaction kinetics, the apparent reaction series a, b, c aboutinitial concentration, dosing quantity of H2O2, the addition of catalysts of printing anddyeing wastewater from the experiments are respectively1.15,0.64and1.15, activationenergy is87.1KJ·mol-1, and the reaction kinetics equation of printing and dyeingwastewater is obtained.