Influence of Industrial Wastewater Quality on Advanced Treatment of Microbubble Ozonation

Abstract

The treatment performance of microbubble ozonation used for advanced treatment of actual pharmaceutical wastewater and tannery wastewater was investigated and compared to show the influence of complicated wastewater quality. The results showed that most organic pollutants in pharmaceutical wastewater and tannery wastewater could be degraded by microbubble ozonation effectively. and COD was removed simultaneously. In addition, the biodegradability was improved and the bio-toxicity was eliminated significantly. The ratios of COD amount removed and ozone amount consumed were 0.77 and 1.02, respectively, in such advanced treatment of pharmaceutical wastewater and tannery wastewater, indicating different ozone oxidation efficiencies between pharmaceutical wastewater and tannery wastewater. The main types of organic pollutants in pharmaceutical wastewater and tannery wastewater were determined by GC-MS and 3D-EEM, which showed the influence on treatment performance of microbubble ozonation. More refractory complex aromatic organic pollutants were found in pharmaceutical wastewater, which seemed more difficult to undergo degradation by microbubble ozone oxidation. As a result, the microbubble ozone oxidation of pharmaceutical wastewater was less efficient than that of tannery wastewater. The inorganic anions in both kinds of wastewater were unfavorable for ozone mass transfer, ozone decomposition, and·OH generation, which reduced the reaction efficiency of microbubble ozonation as well as biodegradability improvement. The lower concentrations of inorganic anions were better for microbubble ozonation.