School of Water Resources and Environment, China University of Geosciences, Beijing 100083, People's Republic of China; Jixi Ecological Environment Monitoring Center, Heilongjiang Province 158305, People's Republic of China.
School of Water Resources and Environment, China University of Geosciences, Beijing 100083, People's Republic of China.
Ecotoxicol Environ Saf. 2024 Jan 1;269:115734. doi: 10.1016/j.ecoenv.2023.115734. Epub 2023 Nov 27.
Dissolved organic matter (DOM) which can help the transportation of nutrients and pollutants plays essential role in the aquatic ecosystems. However, the dynamics of individual DOM component under the change of latitude have not been elucidated to date. The composition and dynamics of DOM were assessed in this study. Two individual parallel factor analysis (PARAFAC) components were found in each sampling site in Heilongjiang. To further characterize the inner change of the identified PARAFAC components, two-latitude correlation spectroscopy (2DCOS) technique was applied to the excitation loadings data. Interestingly, not all the fluorophore in a PARAFAC component change in the same direction as the overall change of a component. From upstream to downstream, the peak A1 in PARAFAC component C1 showed a downward trend, but peak A2 presented an upward trend. In PARAFAC component C2, the peak T2 and peak T3 showed an inverse changing trend under latitude perturbation. Furthermore, basic nutrients parameters in Heilongjiang were also characterized in each sampling sites. The relationships between DOM and nutrients showed that component C1 made a significant contribution to chemical oxygen demand (COD) and biochemical oxygen demand (BOD5). The evolutions of DOM peak A1 and peak A2 were accompanied by the changing of Total phosphorus (TP). The findings in this study could make a contribution to explore the fate of DOM in high humic-like substance containing river.
溶解有机质（DOM）可以帮助营养物质和污染物的运输，在水生生态系统中起着至关重要的作用。然而，迄今为止，还没有阐明纬度变化下单个 DOM 成分的动态变化。本研究评估了 DOM 的组成和动态。在黑龙江的每个采样点都发现了两个个体平行因子分析（PARAFAC）成分。为了进一步描述所识别的 PARAFAC 成分的内部变化，应用双纬度相关光谱（2DCOS）技术对激发载荷数据进行分析。有趣的是，并非 PARAFAC 成分中的所有荧光团都与成分的整体变化朝着相同的方向变化。从上游到下游，PARAFAC 成分 C1 中的峰 A1 呈下降趋势，而峰 A2 呈上升趋势。在 PARAFAC 成分 C2 中，在纬度扰动下，峰 T2 和峰 T3 呈现出相反的变化趋势。此外，还对黑龙江的每个采样点的基本营养参数进行了表征。DOM 与营养物质之间的关系表明，成分 C1 对化学需氧量（COD）和生化需氧量（BOD5）有显著贡献。DOM 峰 A1 和峰 A2 的演变伴随着总磷（TP）的变化。本研究中的发现有助于探索富含腐殖质的河流中 DOM 的命运。
