Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences, 50 Zhongling Street, Nanjing, 210014, China.
Key Laboratory of Agro-Environment in downstream of Yangze Plain, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Nanjing, 210014, China.
Environ Sci Pollut Res Int. 2021 Jun;28(21):26584-26594. doi: 10.1007/s11356-021-12517-5. Epub 2021 Jan 23.
With the increased interest in the practical use of hydrochar, concerns about the possible environmental biotoxicity of hydrochar and its released dissolved organic matters (DOM) have grown. As a common method for removing bio-oil on the surface of hydrochar, the effect of organic solvent washing on the properties of hydrochar released DOM remains unclear. In this study, we made a comprehensive comparison of hydrochar properties and molecule structure as well as biotoxicity of DOM released from HC (raw hydrochar) and THC (hydrochar washed by tetrahydrofuran). The results indicated that the mass loss of hydrochar was obvious after tetrahydrofuran (THF) washing, and a decline of H/C atomic ratio and increase of N/C and O/C atomic ratios was observed based on Van Krevelen (VK) diagram. This result was further confirmed by FTIR, C NMR, and XPS results. Meanwhile, the molecule structure of DOM was shifted to lower molecule weight with higher O-contain compounds after THF extraction due to the demethanation process. However, the biotoxicity experiments indicated that both extracted DOM had no significant impact on germination rate of wheat, and HC-treated sample even exhibited growth superiority. Nevertheless, potential toxicity was observed with the increase of the activity of antioxidant enzymes, and THF washing aggravated the potential oxidative damage through increasing the aromaticity of DOM. Such understanding highlights the importance of evaluating hydrochar and its released DOM before applications, so as to reduce the potential environment biotoxicity.
随着人们对水热炭实际应用的兴趣增加，对水热炭及其释放的溶解有机物（DOM）可能产生的环境生物毒性的担忧也与日俱增。有机溶剂洗涤作为去除水热炭表面生物油的常用方法，其对水热炭释放 DOM 性质的影响尚不清楚。在本研究中，我们综合比较了 HC（原水热炭）和 THC（经四氢呋喃洗涤的水热炭）释放的 DOM 的水热炭性质、分子结构和生物毒性。结果表明，四氢呋喃（THF）洗涤后水热炭的质量损失明显，根据范克雷维伦（VK）图观察到 H/C 原子比下降，N/C 和 O/C 原子比上升。FTIR、C NMR 和 XPS 结果进一步证实了这一结果。同时，由于脱甲烷过程，DOM 的分子结构向低分子量、含氧量更高的化合物转移。然而，生物毒性实验表明，两种提取的 DOM 对小麦发芽率均无显著影响，且 HC 处理的样品甚至表现出生长优势。然而，随着抗氧化酶活性的增加，会观察到潜在的毒性，THF 洗涤通过增加 DOM 的芳香度加剧了潜在的氧化损伤。这种理解强调了在应用之前评估水热炭及其释放的 DOM 的重要性，以降低潜在的环境生物毒性。
