Carena Luca, Vione Davide
Dipartimento di Chimica, Università di Torino, Via Pietro Giuria 5, 10125 Torino, Italy.
Molecules. 2020 Jan 20;25(2):424. doi: 10.3390/molecules25020424.
The abiotic photochemical reactions that take place naturally in sunlit surface waters can degrade many contaminants that pose concern to water bodies for their potentially toxic and long-term effects. This works aims at assessing the ability of European rivers to photoproduce reactive transient intermediates, such as HO radicals and the excited triplet states of chromophoric dissolved organic matter (CDOM*), involved in pollutant degradation. A photochemical mapping of the steady-state concentrations of these transients was carried out by means of a suitable modeling tool, in the latitude belt between 40 and 50°N. Such a map allowed for the prediction of the photochemical lifetimes of the phenylurea herbicide isoproturon (mostly undergoing photodegradation upon reaction with HO and especially CDOM*) across different European countries. For some rivers, a more extensive dataset was available spanning the years 1990-2002, which allowed for the computation of the steady-state concentration of the carbonate radicals (CO). With these data, it was possible to assess the time trends of the photochemical half-lives of further contaminants (atrazine, ibuprofen, carbamazepine, and clofibric acid). The calculated lifetimes were in the range of days to weeks, which might or might not allow for efficient depollution depending on the river-water flow velocity.
在阳光照射的地表水自然发生的非生物光化学反应可以降解许多因其潜在毒性和长期影响而对水体造成威胁的污染物。这项工作旨在评估欧洲河流光生成参与污染物降解的活性瞬态中间体的能力，例如羟基自由基（HO）和发色溶解有机物的激发三重态（CDOM*）。借助合适的建模工具，在北纬40至50°的纬度带内，对这些瞬态中间体的稳态浓度进行了光化学绘图。这样的地图可以预测苯基脲类除草剂异丙隆在不同欧洲国家的光化学寿命（主要在与HO尤其是CDOM*反应时发生光降解）。对于一些河流，有1990年至2002年期间更广泛的数据集，这使得能够计算碳酸根自由基（CO）的稳态浓度。利用这些数据，可以评估其他污染物（阿特拉津、布洛芬、卡马西平和氯贝酸）光化学半衰期的时间趋势。计算出的寿命在数天至数周的范围内，这可能允许也可能不允许根据河水流动速度进行有效的污染清除。
