Abstract
Water quality estimation tools based on real-time monitoring are essential for the effective management of organic pollution in watersheds. This study aims to monitor changes in the levels of chemical oxygen demand (COD, CODMn) and dissolved organic matter (DOM) in Erhai Lake Basin, exploring their relationships and the ability of DOM to estimate COD and CODMn. Excitation emission matrix–parallel factor analysis (EEM–PARAFAC) of DOM identified protein-like component (C1) and humic-like components (C2, C3, C4). Combined with random forest (RF), maximum fluorescence intensity (Fmax) values of components were selected as estimation parameters to establish models. Results proved that the COD of rivers was more sensitive to the reduction in C1 and C2, while CODMn was more sensitive to C4. The DOM of Erhai Lake thrived by internal sources, and the relationship between COD, CODMn, and DOM of Erhai Lake was more complicated than rivers (inflow rivers of Erhai Lake). Models for rivers achieved good estimations, and by adding dissolved oxygen and water temperature, the estimation ability of COD models for Erhai Lake was significantly improved. This study demonstrates that DOM-based machine learning can be used as an alternative tool for real-time monitoring of organic pollution and deepening the understanding of the relationship between COD, CODMn, and DOM, and provide a scientific basis for water quality management.
Highlights
The one-way ANOVA test showed that there was no significant variation in each variable among different depths (p > 0.05) (Table S4); for all variables, the average values of surface water and bottom water are discussed (Table S5)
Similar to other lakes in China, our results showed that COD and CODMn of the lake reached their peak in summer, which may be related to phytoplankton detritus and the release of dissolved organic matter from phytoplankton [52,53,54,55]
We adopted random forest (RF) to estimate COD and CODMn in the Erhai Lake Basin based on dissolved organic matter (DOM) components
Summary
With the acceleration of the industrialization process, the problem of organic pollution in receiving river basins has become increasingly prominent [1,2]. Erhai Lake Basin, a local drinking water source, has caused deterioration of the aquatic ecosystem and poses a threat to human health [3]. Continuous water quality monitoring and evaluation for organic matter are essential for rapid pollution control, to ensure the reliability of drinking water, and to help understand the ecosystem functioning of the basin. Chemical oxygen demand (COD and CODMn) tests are widely used to determine the organic content of watersheds [4].
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
