Study On Degradation Of Aqueous Methyl Orange Solution With Ultrasonic Assisted Fenton Reagent

Sonochemistry is a new branch of chemistry and chemical engineering. Ultrasound can intensify the process of mass transfer, heat transfer and chemical reaction, and can raise the rate of chemical process.Sonochemical oxidation makes use of cavitations phenomenon result from ultrasound. The formation, growth, and subsequent collapse of millions of microbubbles or cavities occur in extremely short intervah (micro-seconds). In the process, large amount of energy is released. Cavitations can bring on generation of local hot spots, release of highly reactive free radicals, continuous cleaning as well as an increase in the surface area (resulting from fragmentation and deagglomeration) of the solid catalysts, and enhancement in the mass transfer rates attributed to turbulence generated by acoustic streaming.The discharge amount of dye waste water reported is as much as 3×10⁶ - 3×10⁶t³ /d. Dye waste water could not be treated effectively with traditional method for its deep color, poor biochemical degradation and complicated components. Therefore, worldwide attention has been paid on exploring novel techniques to degrade dye waste water.A new method to degrade dye waste water was studied in the current dissertation. For convenient, methyl orange (MO) solution was taken as a representative of dye waste water. MO degraded by Ultrasonic assistant Fenton was studied in the experiments. The main results were as following:(1) Degradation of MO was studied by different methods include Fenton reagent degradation, ultrasonic (US) degradation, ultrasonic-Fenton reagent degradation. The results showed that US/Fenton was the most efficient process for MO degradation. MO degradation could be promoted by ultrasonic. Effects of Fenton reagent amount, initial pH value and concentration of MO on MO degradation were also studied.(2) Study on degradation residue indicated that MO was degraded and the final product is H₂O, CO₂, NO₃^-, SO₄^2- and other non-degradable compounds.(3) By the methods of ultrasound, Fenton reagent and ultrasound-Fenton, performance and mechanism of decolorization and COD removal of methyl orange were investigated. Results indicated that with ultrasound solely, decolorization was low. When 400mg/L methyl orange solution was treated 30 min by Fenton reagent, the decolorization ratio and COD removal ratio were 67.51% and 63.15%. In the same operation conditions, the...