微气泡O3/H2O2深度处理某化工园区二级出水效能与机制

化工园区废水经过二级处理后，仍含有多种有毒污染物，依然对生态环境存在较大风险，为此，建立微气泡O₃/H₂O₂深度处理工艺，研究某工业园区二级出水处理效能，确定最佳工艺参数，探究污染物降解机制，并对处理出水进行毒性评价。结果表明：在pH为7.3、臭氧投加量为60 mg/L、H₂O₂初始投加量为114 mg/L、反应时间为15 min条件下，微气泡O₃/H₂O₂对二级出水中有毒污染物具有良好的降解效果，COD和TOC去除率分别达到47.41%和46.61%;微气泡O₃能够显著提高臭氧利用效率，缩短反应时间；与普通O₃曝气相比，臭氧利用率提高10%,反应时间缩短2/3;微气泡O₃/H₂O₂工艺过程中，有机物去除过程遵循表观二级反应动力学；电子顺磁共振(EPR)技术证明羟基自由基(·OH)参与有机物的降解过程，H...

Efficiency and mechanism of microbubble O3/H2O2 advanced treatment of secondary effluent from a chemical park

The secondary effluent of the chemical industry park contains a variety of toxic pollutants, which still poses a great risk to the ecological environment. In this study, the microbubble O₃/H₂O₂ process was established for advanced treatment of secondary effluent from a chemical industry park, and the operation parameters, pollutant degradation mechanism and toxicity evaluation were studied. The best operating parameters were pH 7.3, ozone dosage 60 mg/L, H₂O₂ initial dosage 114 mg/L, reaction time 15 min. Under this condition, the removal rates of COD and TOC were 47.41% and 46.61% respectively in microbubble O₃/H₂O₂ process. The microbubble O₃ can significantly improve the ozone utilization efficiency and shorten the reaction time. Compared with ordinary O₃ aeration, the ozone utilization rate increased by 10% and the reaction time shortened by two thirds. The removal process of organics by microbubble O₃/H₂O₂ process followed the apparent second-order reaction kinetics; the electron paramagnetic resonance (EPR) technology proved that hydroxyl radical (·OH) played a role in the degradation of organic substances, H₂O₂ promoted the formation of ·OH and microbubbles aeration promoted the production of more ·OH by O₃/H₂O₂ through the process. Dissolved organic matter had the tendency of transforming macromolecular substances into small molecular substances in the process of advanced treatment. H₂O₂ can enhance the removal ability of ozone to hydrophobic neutral components and change the degradation path of ozone to pollutants. Compared with 100% luminescence inhibition rate of microbubble O₃, the luminescence inhibition rate of microbubble O₃/H₂O₂ was less than 20%, suggesting that the addition of H₂O₂ can effectively inhibit the increase of acute toxicity.