Study On Degradation Of Dyeing Wastewater By Ultrasound-Fenton Method

China is the largest textile printing and dyeing country,and the textile printing and dyeing industry is the major industrial wastewater producer,it is about 35%of all industrial wastewater emissions.The discharge amount of dye waste water reported is approximately 4×10⁶m³/d.Dye waste water is one of the most difficult to treat wastewater,because it has the characteristic as:very large amount,high chromatic, complex component,bigness water quality change and biology toxicity,difficult to degrade,and no easy to oxidation and photolysis and so on.Advanced oxidation technology is a new wastewater treatment technologies which applied to the wastewater treatment in recent years,and it is becoming a hot research.Fenton reagent oxidation of dye wastewater has made some effect,but there are some drawbacks on the Fenton reagent oxidation alone:such as the utilization of hydrogen peroxide is not high;in general plus more ferrous salt to improve the effectiveness of Fenton oxidation reagents,which susceptible oxidation to formation of secondary pollution.The ultrasound technology was the emerging technology which several years developed recently,had the degeneration condition temperate,the faster reaction rate and the applicable scope broad and so on the merits,but the ultrasound as one kind of emerging technology and the edge discipline,still occupied at present the basic research stage.In recent years some scholars at home and abroad have begun to study the methods of ultrasound cooperate with and other methods,but such research is still in the early stage,it is possible bring new vitality for wastewater treatment technologies to combine the ultrasonic treatment with the traditional technology.Papers will research combine the ultrasonic oxidation with Fenton reagent to deal with a simulated dye wastewater of methyl orange in order to study the rule of the degradation processThe study found:the color removal rate is over 90%after Fenton reaction for 40 minutes,while the color removal rate reached 90%with the combination of ultrasound and Fenton in about 10 minutes,greatly accelerated the color wipe off.In COD removal,the individual ultrasonic degradation is the rate of 9,a separate Fenton degradation rate is 69,whichever the effect of combination of 83 percents.We can see that ultrasound can promote the Fenton reaction,and the effects of combination increased 5%than ultrasound and Fenton's superposition,it can be seen in ultrasound and Fenton have a certain synergy;Getting the best reaction conditions:the pH is 4, the raw water concentration is 100mg/L,Fe²⁺ concentration is 8mg/L,H₂O₂ concentration is 400mg/L.The experiment also showed that phosphate ions,chloride ions inhibit the reaction,while the purple light conditions have a very good role in the system.