Wang Liangjie, Sun Zhengyi, Shi Jinrui, Li Han, Fu Tao, Xu Yi, Xiao Ke, Zhao Huazhang
The Key Laboratory of Water and Sediment Sciences (Ministry of Education), College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China; Water Science and Environmental Engineering Research Center, College of Chemical and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, China.
Water Res. 2025 Feb 1;269:122804. doi: 10.1016/j.watres.2024.122804. Epub 2024 Nov 16.
In phenol-rich wastewater, such as coking wastewater, due to the high reactivity of phenol to various reactive oxygen species, it is difficult to selectively oxidize pollutants having lower biodegradability and higher toxicity than phenol. As one kind of such pollutants in coking wastewater, some nitrogenous heterocyclic compounds (NHCs) are more difficult to be removed by SO or HO• than phenol, but this study found that NHCs (quinoline, isoquinoline, and pyridine) can be selectively removed by peroxymonosulfate (PMS) direct oxidation in the presence of 10 mM phenol under thermal condition. The selective oxidation of NHCs needs a suitable pH range (4 < constant pH < 9) because protonated state of NHCs (pH < 4) is unfavorable to their oxidation and high pH would improve the extra PMS consumption by phenol. Under the conditions benefiting the removal of NHCs in heat/PMS system, there was no generation of SO and HO•. Being treated by 60 °C/PMS for 60 min, the biodegradability (BOD/COD) of real coking wastewater (RCW) was improved from 0.21 to 0.44 with low removal rate of phenols (about 10 %). Quinoline and indole, as the two typical NHCs in the studied RCW, their removal rates can be up to 45 % and 85 %, respectively. Thus, heat/PMS pretreatment is a potential good way to selectively remove high toxic pollutants in phenol-rich wastewater.
在富含苯酚的废水中，如焦化废水，由于苯酚对各种活性氧具有高反应性，因此难以选择性氧化比苯酚生物降解性更低且毒性更高的污染物。作为焦化废水中此类污染物的一种，一些含氮杂环化合物（NHCs）比苯酚更难通过SO或HO•去除，但本研究发现，在热条件下，在10 mM苯酚存在下，NHCs（喹啉、异喹啉和吡啶）可通过过一硫酸盐（PMS）直接氧化被选择性去除。NHCs的选择性氧化需要合适的pH范围（4 < 恒定pH < 9），因为NHCs的质子化状态（pH < 4）不利于其氧化，而高pH会增加苯酚对额外PMS的消耗。在有利于热/PMS系统中NHCs去除的条件下，不会生成SO和HO•。用60 °C/PMS处理60分钟后，实际焦化废水（RCW）的生物降解性（BOD/COD）从0.21提高到0.44，而苯酚的去除率较低（约10%）。喹啉和吲哚作为所研究的RCW中的两种典型NHCs，它们的去除率分别可达45%和85%。因此，热/PMS预处理是选择性去除富含苯酚废水中高毒性污染物的一种潜在的好方法。
