Gu Xincai, Chen Bingfa, Liu Hong, Feng Yanfang, Wang Bingyu, He Shiying, Feng Muhua, Pan Guojun, Han Shiqun
Jiangsu Key Laboratory of Environmental Science and Technology, School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China; Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
J Hazard Mater. 2024 Jan 5;461:132591. doi: 10.1016/j.jhazmat.2023.132591. Epub 2023 Sep 21.
Hydrochar-derived dissolved organic matter (HDOM) enters aquatic ecosystems through soil leaching and surface runoff following the application of hydrochar. However, the photochemical behavior of HDOM remains unclear. The photo-transformation of HDOM was analyzed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), multiple spectroscopy methods, high-performance liquid chromatography, and combining synchronous fluorescence and Fourier-transform infrared spectroscopy with two-dimensional correlation spectroscopy. The results showed that with the increase of carbonization temperature, amide II in protein-like substances were observed to be preferentially photolyzed, and the protein-like substances were more sensitive to low irradiation time, while the duration time of the photochemical behavior of amide II and aliphatic C-H were more persistent. FT-ICR MS results showed that N and S-containing molecules, including lignins and lipids were more sensitive to ultraviolet irradiation. Furthermore, the photo-transformation of HDOMs was accompanied by the generation of triple excited state dissolved organic matter and singlet oxygen. Our findings will be beneficial for understanding the mechanisms of photo-transformation of HDOM and for predicting the possible behaviors of hydrochar produced at different temperatures before large-scale application.
水炭衍生的溶解有机物（HDOM）在施用后通过土壤淋溶和地表径流进入水生生态系统。然而，HDOM的光化学行为仍不清楚。通过傅里叶变换离子回旋共振质谱（FT-ICR MS）、多种光谱方法、高效液相色谱以及将同步荧光和傅里叶变换红外光谱与二维相关光谱相结合，对HDOM的光转化进行了分析。结果表明，随着碳化温度的升高，观察到类蛋白质物质中的酰胺II优先被光解，类蛋白质物质对低辐照时间更敏感，而酰胺II和脂肪族C-H光化学行为的持续时间更长。FT-ICR MS结果表明，含N和S的分子，包括木质素和脂质，对紫外线照射更敏感。此外，HDOMs的光转化伴随着三重激发态溶解有机物和单线态氧的产生。我们的研究结果将有助于理解HDOM光转化的机制，并预测不同温度下生产的水炭在大规模应用前的可能行为。
