Study on regulation rules of the reactive oxygen species generation and vanadium extraction from vanadium slag enhanced by oxygen microbubbles in alkaline medium

 The application of microbubble enhanced oxidation technology in alkaline environments is becoming increasingly extensive． Ｒelevant studies have shown that its enhanced oxidation mechanism mainly lies in the accelerated generation of reactive oxygen species，including HO 2 and ·OH． Nevertheless，relevant research in alkaline media，especially concentrated alkaline solutions，is still insufficient． It is urgent to clarify the quantitative regulation law of HO 2 and·OH generation enhanced by microbubbles to provide theoretical support for the application of microbubble enhanced oxidation technology in complex alkaline systems． In this paper，Cr( VI) and PNP were used as probe reagents to investigate the variations of HO 2 and ·OH contents with temperature，aerator size and alkali concentration． The key parameters and action mechanisms of oxygen microbubbles regulating reactive oxygen species production in alkaline media were clarified． Meanwhile， the effect of reactive oxygen species generated by microbubble enhancement was further verified through the oxidative leaching experiment of vanadium from vanadium slag． The results indicate that an increase in temperature can promote the production of HO 2 and ·OH． Alkali concentration and aerator size present unique response rules for the formation of HO 2 and·OH． The maximum production amounts of HO 2 and ·OH reach 3．39×10－4 mol/L and 5．45×10－5 mol/L respectively． Under the conditions of 7．5 mol/L NaOH and 100 ℃，high alkali concentration and temperature facilitate the generation of reactive oxygen species． The vanadium leaching rate reaches 97．3% with the introduction of oxygen microbubbles． This research provides a solid theoretical foundation for the optimized application of oxygen microbubble technology in hydrometallurgy and other fields．