Pang Hongjiao, Zhang Jianhua, Allinson Mayumi, Gray Stephen, Scales Peter J
Department of Chemical Engineering, The University of Melbourne, Parkville, VIC 3010, Australia.
Institute for Sustainable Industries and Liveable Cities, Victoria University, Werribee, VIC 3030, Australia.
Water Res. 2023 Apr 1;232:119671. doi: 10.1016/j.watres.2023.119671. Epub 2023 Jan 27.
Ozonation is an effective barrier for removing a wide spectrum of organic Chemicals of Concern (CoC) in a water treatment process. In this study, bench- and full-scale tests were conducted on a secondary treated effluent at the Eastern Treatment Plant (ETP) of Melbourne Water to probe the performance of ozonation in removing CoC in a wastewater discharge. From the secondary treated effluent as the feed to the ozone process, 58 organic chemicals were measured out of a possible 949 compounds by using the AIQS-DB analytical method. A chemical credit framework for the ozonation process has been established according to the bench-scale results. Chemical classifications based on the chemical structures (aromatics, aliphatic and halogenated aliphatic compounds) and reaction rate constants with O (K) and the ∙OH radical (K) and a combined O/TOC ratio and O CT value as operating parameters were confirmed to be useful and important in determining whether a chemical would be removed by ozone. It is shown that an O/TOC ratio of >0.404 was shown to be necessary to overcome the instantaneous ozone demand (IOD) to guarantee enough ozone to oxidise CoC. For CoC with K >10M s and K >10M s , an O/TOC ratio of ≥0.461 or a measurable O CT of ≥0.063 mg min/L can achieve log reduction values (LRVs) of ≥1, these are chemicals with aromatic structures; For CoC with low K and high K, a combined O/TOC ratio and O CT value inclusive of a chemical structure classification is indicated as necessary criteria to evaluate the removal. UV and TOC were demonstrated to be good online surrogates of ozone barrier performance in the absence of continuous O/TOC ratio and O CT value measurements. Full-scale operational results confirm the effective predictions of the chemical credit framework, which highlights the necessity and importance of monitoring both the O/TOC ratio and O CT values to predict the removal efficiency of a given chemical with a known response to O or a known chemical structure.
臭氧化是水处理过程中去除多种关注的有机化学品（CoC）的有效屏障。在本研究中，对墨尔本水务公司东部污水处理厂（ETP）的二级处理出水进行了实验室规模和全尺寸测试，以探究臭氧化在去除废水排放中的CoC方面的性能。以二级处理出水作为臭氧工艺的进水，通过AIQS-DB分析方法，在可能的949种化合物中检测出了58种有机化学品。根据实验室规模的结果建立了臭氧化过程的化学信用框架。基于化学结构（芳烃、脂肪族和卤代脂肪族化合物）以及与O（K）和∙OH自由基（K）的反应速率常数，并将O/TOC比值和O CT值作为运行参数进行化学分类，被证实对于确定一种化学品是否会被臭氧去除是有用且重要的。结果表明，要克服瞬时臭氧需求（IOD）以保证有足够的臭氧来氧化CoC，O/TOC比值需>0.404。对于K>10M s 且K>10M s 的CoC，O/TOC比值≥0.461或可测量的O CT≥0.063 mg min/L可实现对数去除值（LRV）≥1，这些是具有芳香结构的化学品；对于K低且K高的CoC，表明将O/TOC比值和O CT值与化学结构分类相结合作为评估去除效果的必要标准。在没有连续测量O/TOC比值和O CT值的情况下，紫外线（UV）和总有机碳（TOC）被证明是臭氧屏障性能的良好在线替代指标。全尺寸运行结果证实了化学信用框架的有效预测，这突出了监测O/TOC比值和O CT值以预测已知对O有响应或已知化学结构的特定化学品去除效率的必要性和重要性。
