| 引用本文: | 刘新,吴定桂,江和龙,宋娜.草源型可溶性有机物降解过程中活性氧物种产生过程.湖泊科学,2020,32(2):440-449. DOI:10.18307/2020.0213 |
| LIU Xin,WU Dinggui,JIANG Helong,SONG Na.The production process of reactive oxygen radicals in the degradation process of grass-source dissolved organic matter. J. Lake Sci.2020,32(2):440-449. DOI:10.18307/2020.0213 |
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| 摘要: |
| 活性氧物种（ROS）参与天然水体系统中的光化学反应、氧化还原反应，是影响水体中有机污染物的迁移、转化、环境归宿及生态效应的重要因素.然而目前对草源型可溶性有机物（DOM）分解过程中ROS的产生过程并不清楚.本文通过室内模拟实验，首先构建了室内测定3种ROS （3CDOM*、1O2、·OH）的方法，进而分析草源植物——苔草（Carex tristachya）残体浸出液中DOM光降解过程中ROS的产生过程.结果表明：ROS累积含量的产生随着DOM的降解逐渐升高，在3种自由基含量中，3CDOM*的产生含量最多，·OH产生含量低于另外2种ROS两个数量级.CDOM含量与3CDOM*、1O2、·OH浓度呈现正相关关系，尤其与3CDOM*和1O2浓度的显著性水平最高，·OH次之.ROS浓度与水质指标呈现出不同的线性相关关系，与硝态氮浓度呈负相关关系，而与亚硝态氮浓度呈现正相关关系，并且亚硝态氮对ROS浓度影响效果极显著.同时类蛋白荧光峰值强度的衰减与ROS累积含量呈现极显著负相关关系，说明在DOM的光降解过程中蛋白质小分子的降解是产生ROS很重要的一个部分.综上，通过对草源型DOM光降解过程中ROS产生过程的研究，增加了对湖泊生态系统中水生植物产生ROS的过程、迁移、转化、归宿及其作用机制的认识. |
| 关键词: 可溶性有机物 活性氧物种 植物残体 光降解 湖泊水体 |
| DOI：10.18307/2020.0213 |
| 分类号: |
| 基金项目:国家自然科学基金项目（51879256， 5187091383）和江苏省高校优势学科建设工程资助项目（PAPD）联合资助. |
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| The production process of reactive oxygen radicals in the degradation process of grass-source dissolved organic matter |
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LIU Xin1, WU Dinggui1,2, JIANG Helong2, SONG Na2
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1.Nanjing Forestry University, College of Biology and the Environment, Key Laboratory of Environmental Engineering of Jiangsu Province, Nanjing 210037, P. R. China;2.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P. R. China
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| Abstract: |
| Reactive oxygen species (ROS) participate in photochemical reactions and redox reactions in natural water systems, and are important factors affecting the migration, transformation, environmental destination and ecological effects of organic pollutants in water. However, ROS production process in the degradation of grass-source soluble organic matter (DOM) is not clear at present. In this paper, an indoor simulation experiment was conducted to establish a method for the determination of the cumulative values of three ROS (3CDOM*, 1O2 and·OH) in the laboratory, and then the production process of ROS in the DOM photodegradation process in the residual leaching solution of Carex tristachya was analyzed. Results showed that the cumulative content of ROS increased with the degradation of DOM. Among the three free radical contents, 3CDOM* has the highest production content, and·OH production content was two orders of magnitude lower than the other two ROS. CDOM content was significantly positively correlated with the cumulative concentration of 3CDOM*, 1O2 and·OH, especially with the highest significance level of 3CDOM* and 1O2, followed by·OH, consistent with the ROS production mechanism of CDOM. The accumulation value of ROS concentration has a different linear correlation with the water quality index, which is negatively correlated with nitrate nitrogen, but positively correlated with nitrite nitrogen(NO2--N), and the effects of NO2--N on ROS concentration are extremely significant. Meanwhile, the attenuation of the peak fluorescence intensity of protein-like proteins is negatively correlated with the cumulative content of ROS, indicating that the degradation of small protein molecules is an important part of the ROS production in the process of DOM photodegradation. In conclusion, the research on ROS production process in the photodegradation process of grass-source DOM has increased the understanding of ROS production process, migration, transformation, home and mechanism of aquatic plants in the lake ecosystem. |
| Key words: Dissolved organic matter reactive oxygen species plant residue photodegradation lake waters |
