| Industrial wastewater has the characteristics of high pollutant concentration,poor biodegradability,strong biological toxicity,complex water quality conditions and large fluctuation,so it needs to adopt pretreatment or advanced treatment to improve the treatment effect.In this study,microbubble ozonation technology was applied to the pretreatment and advanced treatment of industrial wastewater to investigate the performance of pollutant treatment and the influence of complex water quality conditions on the performance of microbubble ozonation.The results showed that:1)Two kinds of pharmaceutical wastewater(ZYTC1 and ZYTC2,with initial COD concentration of 7017 and 8201mg·L-1,respectively)were pretreated by microbubble ozonation technology.After 60 minutes of reaction,the COD removal rates of ZYTC1 and ZYTC2 were 24.62%and 57.38%respectively,and the reaction efficiencices R?the ratio of cumulative COD removal to O3 consumption?were 2.90 and 6.75 respectively,and the removal rates of UV254 were 19.78%and 24.81%respectively.Pretreatment improved the biodegradability and reduced the biological toxicity significantly,and B/C increased from0.033 and 0.022 to 0.291 and 0.808 respectively,and the equivalent concentrations of HgCl2decreased from 13.95 and 10.20mg·L-1 to 10.88 and 4.70 mg·L-1 respectively.The type of organic matter and initial pH had obvious influence on the treatment effect:the content of refractory protein in ZYTC1 was high,and the ozonation effect was poor;the pretreatment effect of the two kinds of wastewater had been significantly improved under the alkaline condition.2)The microbubble ozonation technology was used for advanced treatment of actual pharmaceutical wastewater biochemical treatment effluent?ZYEC?and actual tannery wastewater biochemical treatment effluent?ZGEC?wastewater(with initial COD concentration of 519 and 219 mg·L-1,respectively).After 60 minutes of reaction,the COD removal rates of ZYEC and ZGEC were 32.48%and 45.06%respectively,and the reaction efficiencice R were 0.77 and 1.02 respectively,and the removal rates of UV254 were 56.80%and 73.60%respectively.After advanced treatment,the biodegradability was improved and toxicity was also declined significantly,and B/C increased from 0.027 and 0.089 to 0.089and 0.191 respectively,and the equivalent concentration of HgCl2 decreased from 0.143 and0.071mg·L-1 to 0.079 and 0.042mg·L-1 respectively.3)The influencing factors of the performance of microbubble ozonation for advanced treatment of industrial wastewater included organic matter type,anion concentration and initial pH.GC-MS and 3D-EEM analyses showed that the main pollutants in ZYEC were the macromolecular aromatic organic compounds and long-chain alkanes which were difficult to be degraded,and the ozonation effect was poor.The pollutants in ZGEC were mainly long-chain alkanes with a small amount of aromatic organic compounds,and the ozonation effect was better than that of ZYEC;inorganic anions in wastewater were not conducive to ozone gas-liquid mass transfer and decomposition,and·OH generation,which in turn affected the microbubble ozonation reaction efficiency and biodegradability improvement.Reducing the anion concentration enhanced microbubble ozonation performance.When adjusting the initial pH to alkaline,the effect of advanced treatment of the two kinds of wastewater was improved obviously. |
PDF Full Text Request