Experimental Study On Ultrasonic Enhanced Fe₃O₄-MnO₂ Fenton System For The Treatment Of Methylene Blue Wastewater

Printing and dyeing wastewater has the characteristics of high chroma,high organic content,high toxicity and poor biodegradability.It is a kind of difficult to treat organic wastewater.In recent years,more and more attention has been paid to the treatment of printing and dyeing wastewater by advanced oxidation methods.Among them,Fenton oxidation method is widely known by scholars because of its fast reaction speed and easy operation.However,the Fenton oxidation method has the disadvantages of large dosage,narrow range of p H value,and low catalyst utilization,so it also limits its application.This subject mainly studies the strengthening effect of ultrasound on the Fe₃O₄-Mn O₂Fenton system,experimentally studies the treatment effect of ultrasonically strengthened Fe₃O₄-Mn O₂-PAC Fenton system on methylene blue wastewater and the best process conditions,and provides technology for the popularization and application of Fenton-like oxidation method.in accordance with.In the experiment,the methylene blue simulated printing and dyeing wastewater was used as the treatment object.The effects of the Fenton reagent method,Fe₃O₄-Mn O₂-PAC Fenton reagent method,and ultrasonic-enhanced Fe₃O₄-Mn O₂-PAC Fenton reagent method on the treatment of methylene blue wastewater were investigated in the laboratory.Strengthening effect of ultrasound on Fenton-like reagent method.The traditional Fenton method has a good treatment effect on methylene blue wastewater.The dosage of H₂O₂and Fe SO₄·7H₂O,the p H value and the reaction time all have an effect on the treatment effect,and the dosage of H₂O₂has the largest effect.When p H=3,the dosage of H₂O₂is Q_th（3m L/L）,the dosage of Fe²⁺is 800mg/L,and the reaction time is120min,the color removal rate can reach 98.79%,and the COD removal efficiency can reach81.82%.The experimental results of Fe₃O₄-Mn O₂-PAC-based Fenton method for the treatment of methylene blue wastewater show that the system extends the effective range of p H to 2.5.Fe₃O₄-Mn O₂-PAC composites are used instead of Fe²⁺catalysts.The catalysts can be recycled and reused.p H=3,the dosage of the catalyst Fe₃O₄-Mn O₂-PAC was 0.8g/L,the amount of H₂O₂was 0.8Q_th,and the reaction rate was 99.34%after reacting for 120min at a temperature of 25°C.The removal efficiency of COD was 85.45%.The ultrasonic-enhanced Fe₃O₄-Mn O₂-PAC-based Fenton method has a better treatment effect on methylene blue wastewater.At p H=3,the dosage of catalyst Fe₃O₄-Mn O₂-PAC is0.8g/L,and the dosage of H₂O₂is 0.8Q_th.The temperature was 25°C,the ultrasonic power was 120W,and the ultrasonic frequency was 28KHz.After 120 minutes of reaction,the chroma removal rate was 100%,and the average COD removal rate was 87.62%.Under the condition that the removal effect is maintained,the strengthening of ultrasound can reduce the dosage,The amount of Fe₃O₄-Mn O₂-PAC catalyst was reduced from 0.8g/L to 0.5g/L,and the amount of H₂O₂was reduced from 0.8Q_thto 0.5Q_th.The ultrasonic-enhanced Fe₃O₄-Mn O₂-PAC-based Fenton method has a better treatment effect on methylene blue wastewater,and is a treatment technology worthy of promotion.Compared with the traditional Fenton method,this method not only widens the effective range of p H,but also reduces the dosage of medicament under the condition of comparable removal effect,saves processing costs,and the reuse of catalyst is realized.