Study On The Treatment Of Azo Dye Wastewater By Combination Of Liquid High Voltage Pulsed Discharge And Ozonation

Azo dye wastewater has the features of strong biological toxicity, deep color, high COD, complex compositions and refractory. If azo dye wastewater is direct discharged that will seriously pollute the environment. The practice shows that it is not ideal of the azo dye wastewater effect through the conventional biochemical and physico-chemical methods. Advanced oxidation processes in wastewater treatment has drawn worldwide attention due to its fast reaction velocity, high removal efficiency, harmlessness,Applicability, etc. It is an important research direction that both ozone technology and high voltage pulsed discharge technology.In this paper, the Acid Red B is mixed to simulated wastewater was chosen to be experimental object,and then through degradation experimental study on high voltage pulsed discharge and ozone oxidation technology, which achieved good results. Firstly,selecting four experimental oxidation technology(ozone, high-voltage pulsed discharge,high voltage pulsed discharge with oxygen, high-voltage pulse discharge with ozone) to study the removal efficiency of acid red B wastewater color, COD. Secondly, investigating and analyzing the effect of treatment efficiency through p H、radical scavenger(Na2CO3)and inorganic salt(Na Cl and Na2SO4). Finally, analyzing the mechanism of high-voltage pulsed discharge with ozonation to degrade Acid Red B wastewater.Experimental results show that:(1)The high voltage pulsed discharge can improve the ozone oxidization effect. Using the technology of High voltage pulsed discharge with ozone oxidation. After 10 min, the decolorization rate of azo dye wastewater more than 79%, COD removal efficiency is11%,after 40 min, the decolorization rate is more than 98%, COD removal efficiency is44%.(2)Under the conditions of initial p H is 5.14, 7.56, 9.74 and reaction time is 40 mins,it was found that with the increase of initial p H, the azo dyes decolorization rate is decreased, indicating that it was found that acidic conditions are more conducive to the Acid red B decolorization under the pulse discharge with ozone oxidation.(3)After adding 50 mmol Na2CO3, to Acid Red B, the decolorization rate and COD removal rate of Acid Red B are both reduced, indicating that the Na2CO3 had played inhibitory effect on the hydroxyl radicals.(4)Under high-voltage pulse discharge with Ozone conditions,adding 50 mmol Na Clor Na2SO4 to Acid Red B, It was found that the two salts for the decolorization rate is not obvious, but they can significantly increase COD removal, Adding Na Cl enable the COD removal rate reached 75.79%, Adding Na2SO4 enable the COD removal rate reached53.32%.(5)By the GC/MS and IC, the analysis of degradation of Acid Red B can be initially speculated that the azo bond of Acid Red B molecules were disconnected and thus generate aromatic aminesthen be oxidized to nitrobenzene and benzene sulfonamide acid.Final, the part of the product will be oxidized to acetic acid, formic acid, oxalic acid,nitrate, sulfate. In the light of the results,the proposed pathways of degradation of Acid Red B was put forword.