Hongyu Ding, Mingxia Zheng, Lina Yan, Xiaoyu Zhang, Lu Liu, Yuanyuan Sun, Jing Su, Beidou Xi, Huibin Yu
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引用次数: 0
Abstract
Dissolved organic matter (DOM) represents one of the most active elements in aquatic systems, whose fraction is engaged in chemical and biological reactions. However, fluorescence, molecular diversity and variations of DOM in groundwater systems with the alteration of surface water recharge remain unclear. Herein, Excitation–emission matrix (EEM) fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) combined with principal component coefficients, parallel factor analyses (PARAFAC) with two‒dimensional correlation spectroscopy (2D-COS) were applied in this study. EEM data reassembled for principal component analysis (PCA) highlighted differences in tryptophan-like peak between groundwater collected parallel to the river (PR) and those taken vertical to the river (VR). PARAFAC have identified six components, i.e., microbial-related humic substances (C1 and C6), protein-like substances (C2 and C5), and terrestrial humic-like substances (C3 and C4). In the PR direction, variations of fluorescence components were dominated by terrestrial humic-like substances, while microbial humic-like substances predominated in the VR direction, as revealed by 2D-COS analysis. FT-ICR MS data showed a similar DOM molecular evolution trend in groundwater. Specifically, biodegradable molecular formulas decreased with a diminishing contribution of river water to groundwater recharge. This decrease was accompanied by a decrease in O3S and O5S components, which highlight the influence of anthropogenic river water on groundwater DOM characteristics. Groundwater DOM variations were attributed to the influx of bioavailable and low-oxidized components and the release of terrestrial humic-like substances during river water recharge processes. This study contributes valuable insights into the transformations of DOM in groundwater systems influenced by surface water recharge, enhancing our understanding of the interplay between surface water and groundwater quality.
期刊介绍:
Water Research, along with its open access companion journal Water Research X, serves as a platform for publishing original research papers covering various aspects of the science and technology related to the anthropogenic water cycle, water quality, and its management worldwide. The audience targeted by the journal comprises biologists, chemical engineers, chemists, civil engineers, environmental engineers, limnologists, and microbiologists. The scope of the journal include:
•Treatment processes for water and wastewaters (municipal, agricultural, industrial, and on-site treatment), including resource recovery and residuals management;
•Urban hydrology including sewer systems, stormwater management, and green infrastructure;
•Drinking water treatment and distribution;
•Potable and non-potable water reuse;
•Sanitation, public health, and risk assessment;
•Anaerobic digestion, solid and hazardous waste management, including source characterization and the effects and control of leachates and gaseous emissions;
•Contaminants (chemical, microbial, anthropogenic particles such as nanoparticles or microplastics) and related water quality sensing, monitoring, fate, and assessment;
•Anthropogenic impacts on inland, tidal, coastal and urban waters, focusing on surface and ground waters, and point and non-point sources of pollution;
•Environmental restoration, linked to surface water, groundwater and groundwater remediation;
•Analysis of the interfaces between sediments and water, and between water and atmosphere, focusing specifically on anthropogenic impacts;
•Mathematical modelling, systems analysis, machine learning, and beneficial use of big data related to the anthropogenic water cycle;
•Socio-economic, policy, and regulations studies.