文献类型： 外文期刊

作者： Xiao, Yanchun ¹ ; Yu, Huibin ² ; Song, Yonghui ² ;

作者机构： 1.Fujian Acad Agr Sci, Inst Agr Engn Technol, Fuzhou 350003, Peoples R China

2.Chinese Res Inst Environm Sci, Watershed Res Ctr Comprehens Treatment Water Envir, Beijing 100012, Peoples R China

关键词： river sediment; fulvic acid fractions; variation; parallel factor analysis; structural equation model

期刊名称：WATER （ 影响因子：3.4； 五年影响因子：3.5 ）

ISSN：

年卷期： 2023 年 15 卷 12 期

页码：

收录情况： SCI

摘要： To identify the influences of anthropogenic activities on the composition, spatial distribution, sources, and transformation mechanism of sedimentary fulvic acid (FA) fractions from different reaches of an urban river were tracked via excitation-emission matrix (EEM) fluorescence spectroscopy with parallel factor (PARAFAC) analysis and two-dimensional correlation spectroscopy (2D-COS). Sediment samples were collected from Baitapu River (BR) along gradients with human activities (e.g., rural, town, and urban sections) in Shenyang, northeast China, from which FA fractions were extracted and then determined via EEM fluorescence spectroscopy. According to optical indices, the autochthonous sources of sedimentary FA fractions in BR were more significant than the terrestrial sources. Among the sections, the contribution from autochthonous sources decreased in the following order: Rural > Urban > Town. Six components of sedimentary FA fractions were identified via EEM-PARAFAC: C1 comprised tryptophan-like (TRL) compounds; C2 was associated with microbial humic-like (MHL) compounds; C3, C4, and C5 were associated with FA-like (FAL) compounds; and C6 comprised humic acid-like (HAL) compounds. The proportion of sedimentary FA fractions decreased in the following order: MHL + FAL + HAL (humus, 77.37-88.90%) > TRL (protein, 11.10-22.63%) for the three sections, showing that humus dominated. The town section exhibited the highest sedimentary FA fractions (5328.87 & PLUSMN; 1315.82 Raman unit [R.U.]), followed by the urban (4146.49 & PLUSMN; 535.75 R.U.) and rural (2510.56 & PLUSMN; 611.00 R.U.) sections. Three pollution sources were determined via principal component analysis (i.e., the dominant industrial source, domestic wastewater, and agricultural effluent). Additionally, the results from 2D-COS revealed that sedimentary FA fractions tended to stabilize as the protein-like component was transformed into the HAL component. Furthermore, we used the structural equation model to validate the critical environmental variables affecting the FA fraction transformation. The results can elucidate the influences of human activities on the dynamics of sedimentary FA fractions in urban rivers.