Optical properties and compositions of dissolved organic matter (DOM) along trophic gradients: Implications for a COD proxy in urban lakes

Abstract

Aiming to control lake eutrophication, proposed methods for convenient and faithworthy lake water quality evaluation are warranted. Optical measurement of dissolved organic matter (DOM) demonstrates great potential for estimating organic matter (OM) composition, and can thus serve as a proxy for conventional chemical oxygen demand (COD_Mn) measurements, which are considered as imprecise and environmentally unfriendly. Hence, we conducted a field campaign across 30 lakes in Wuhan's metropolitan area, collecting 255 samples from varying trophic states to evaluate the predictive capability of COD_Mn using DOM optical measurements combined with parallel factor (PARAFAC) analysis. The DOM optical properties and chemical composition exhibited considerable variability across varying trophic state levels (TSLs). Fluorescence components C1-C3 and C5, fluorescence index (FI), and absorption at 254 nm (α₂₅₄), increased as TSL increased, while the DOM spectral slope (S_R) decreased. COD_Mn was positively and significantly correlated with fluorescence components C1–C3 and C5, freshness index (β/α), autochthonous index (BIX), humification index (HIX), α₂₅₄, the ratio of α₂₅₀ to α₃₆₅ (E2/E3) while being negatively correlated with S_R. Parameters α₂₅₄, C1, C3, C4, FI, β/α, and HIX were identified as key predictors of COD_Mn. The multiple linear regression model successfully predicted COD_Mn (r² = 0.63, p < 0.01, n = 1113) and demonstrated superior performance in mesotrophic lakes. These findings highlight the potential for establishing high-frequency, continuous, and multi-regional COD monitoring programs.

Keywords

chemical oxygen demand / DOM chemical composition / DOM quality / eutrophication / water quality

References

[1] Azadi, F., Ashofteh, P. S., & Chu, X. (2021). Evaluation of the effects of climate change on thermal stratification of reservoirs. Sustainable Cities and Society 66, 102531.

[2] Azadi, F., Ashofteh, P. S., Shokri, A., & Loáiciga, H. A. (2021). Simulation-optimization of reservoir water quality under climate change. Journal of Water Resources Planning and Management, 147(9), 04021054.

[3] Borges, A. V., Darchambeau, F., Teodoru, C. R., Marwick, T. R., Tamooh, F., Geeraert, N., Omengo, F. O., Guérin, F., Lambert, T., & Morana, C. (2015). Globally significant greenhouse-gas emissions from African inland waters. Nature Geoscience, 8(8), 637-642.

[4] Carlson, R. E. (1977). A trophic state index for lakes. Limnology and Oceanography, 22(2), 361-369.

[5] Chen, K., Liu, X., Chen, X., Guo, Y., & Dong, Y. (2020). Spatial characteristics and driving forces of the morphological evolution of East Lake, Wuhan. Journal of Geographical Sciences 30, 583-600.

[6] Cory, R. M., & McKnight, D. M. (2005). Fluorescence spectroscopy reveals ubiquitous presence of oxidized and reduced quinones in dissolved organic matter. Environmental Science & Technology, 39(21), 8142-8149.

[7] Crawford, J. T., Loken, L. C., Casson, N. J., Smith, C., Stone, A. G., & Winslow, L. A. (2015). High-speed limnology: Using advanced sensors to investigate spatial variability in biogeochemistry and hydrology. Environmental Science & Technology, 49(1), 442-450.

[8] Davidson, T. A., Audet, J., Svenning, J. C., Lauridsen, T. L., Søndergaard, M., Landkildehus, F., Larsen, S. E., & Jeppesen, E. (2015). Eutrophication effects on greenhouse gas fluxes from shallow-lake mesocosms override those of climate warming. Global Change Biology, 21(12), 4449-4463.

[9] Dickey, T., Itsweire, E. C., Moline, M., & Perry, M. (2008). Introduction to the Limnology and Oceanography special issue on autonomous and Lagrangian platforms and sensors (ALPS). Limnology and Oceanography, 53(5), 2057-2061.

[10] Du, Y. X., Lu, Y. H., Roebuck, A., Liu, D., Chen, F. Z., Zeng, Q. F., Xiao, K., He, H., Liu, Z. W., Zhang, Y. L., & Jaffe, R. (2020). Direct versus indirect effects of human activities on dissolved organic matter in highly impacted lakes. Science of the Total Environment, 752, 141839.

[11] Duan, G., & Niu, R. (2018). Lake area analysis using exponential smoothing model and long time-series landsat images in Wuhan, China. Sustainability, 10(2), 149.

[12] Dubber, D., & Gray, N. F. (2010). Replacement of chemical oxygen demand (COD) with total organic carbon (TOC) for monitoring wastewater treatment performance to minimize disposal of toxic analytical waste. Journal of Environmental Science and Health Part A, Toxic/Hazardous Substances & Environmental Engineering, 45(12), 1595-1600.

[13] Fang, T., Yang, C., & Liao, L. (2012). Photoelectrocatalytic degradation of high COD dipterex pesticide by using TiO₂/Ni photo electrode. Journal of Environmental Sciences (China), 24(6), 1149-1156.

[14] Goffin, A., Guérin-Rechdaoui, S., Rocher, V., & Varrault, G. (2019). An environmentally friendly surrogate method for measuring the soluble chemical oxygen demand in wastewater: Use of three-dimensional excitation and emission matrix fluorescence spectroscopy in wastewater treatment monitoring. Environmental Monitoring and Assessment, 191(7), 421.

[15] Goldman, J. H., Rounds, S. A., & Needoba, J. A. (2012). Applications of fluorescence spectroscopy for predicting percent wastewater in an urban stream. Environmental Science & Technology, 46(8), 4374-4381.

[16] Gons, H. J., Auer, M. T., & Effler, S. W. (2008). MERIS satellite chlorophyll mapping of oligotrophic and eutrophic waters in the Laurentian Great Lakes. Remote Sensing of Environment 112(11), 4098-4106.

[17] He, D., He, C., Li, P., Zhang, X., Shi, Q., & Sun, Y. (2019). Optical and molecular signatures of dissolved organic matter reflect anthropogenic influence in a coastal river, Northeast China. Journal of Environmental Quality, 48(3), 603-613.

[18] Henderson, R. K., Baker, A., Murphy, K. R., Hambly, A., Stuetz, R. M., & Khan, S. J. (2009). Fluorescence as a potential monitoring tool for recycled water systems: A review. Water Research, 43(4), 863-881.

[19] Hur, J., & Cho, J. (2012). Prediction of BOD, COD, and total nitrogen concentrations in a typical urban river using a fluorescence excitation-emission matrix with PARAFAC and UV absorption indices. Sensors (Basel, Switzerland), 12(1), 972-986.

[20] Hur, J., Lee, B. M., Lee, T. H., & Park, D. H. (2010). Estimation of biological oxygen demand and chemical oxygen demand for combined sewer systems using synchronous fluorescence spectra. Sensors (Basel, Switzerland), 10(4), 2460-2471.

[21] Jiao, N., Liu, J., Edwards, B., Lv, Z., Cai, R., Liu, Y., Xiao, X., Wang, J., Jiao, F., & Wang, R. (2021). Correcting a major error in assessing organic carbon pollution in natural waters. Science Advances, 7, 7318.

[22] Khorsandi, M., Ashofteh, P. S., & Singh, V. P. (2024). Development of a multi-objective reservoir operation model for water quality-quantity management. Journal of Contaminant Hydrology, 205, 104385.

[23] Langergraber, G., Fleischmann, N., & Hofstädter, F. (2003). A multivariate calibration procedure for UV/VIS spectrometric quantification of organic matter and nitrate in wastewater. Water Science and Technology, 47(2), 63-71.

[24] Laurion, I., Ventura, M., Catalan, J., Psenner, R., & Sommaruga, R. (2000). Attenuation of ultraviolet radiation in mountain lakes: Factors controlling the among-and within-lake variability. Limnology and Oceanography, 45(6), 1274-1288.

[25] Li, S., Zheng, F., Cai, S., Liang, W., & Li, Y. (2013). A visible light assisted photocatalytic system for determination of chemical oxygen demand using 5-sulfosalicylic acid in situ surface modified titanium dioxide. Sensors & Actuators, B: Chemical 188, 280-285.

[26] Liu, H., He, B., Zhou, Y., Yang, X., Zhang, X., Xiao, F., Feng, Q., Liang, S., Zhou, X., & Fu, C. (2021). Eutrophication monitoring of lakes in Wuhan based on Sentinel-2 data. GIScience & Remote Sensing 58(5), 776-798.

[27] Liu, H., Xia, J., Zou, L., & Huo, R. (2022). Comprehensive quantitative evaluation of the water resource carrying capacity in Wuhan City based on the “human–water–city” framework: Past, present and future. Journal of Cleaner Production, 366, 132847.

[28] Liu, S. S., Hou, J. W., Suo, C. Y., Chen, J. Y., Liu, X. H., Fu, R., & Wu, F. C. (2022). Molecular level composition of dissolved organic matter in distinct trophic states in Chinese lakes: Implications for eutrophic lake management and the global carbon cycle. Water Research, 217, 118438.

[29] Liu, X., Zhang, Y., Shi, K., Zhu, G., Xu, H., & Zhu, M. (2014). Absorption and fluorescence properties of chromophoric dissolved organic matter: Implications for the monitoring of water quality in a large subtropical reservoir. Environmental Science and Pollution Research, 21(24), 14078-14090.

[30] Luo, J. C., & Li, S. Y. (2021). Optical properties of dissolved organic matter in a monsoonal headwater stream, China: Insights for structure, source and riverine pCO₂. Journal of Cleaner Production, 282, 124545.

[31] Maberly, S. C., Barker, P. A., Stott, A. W., & De Ville, M. M. (2013). Catchment productivity controls CO₂ emissions from lakes. Nature Climate Change, 3(4), 391-394.

[32] McKnight, D. M., Boyer, E. W., Westerhoff, P. K., Doran, P. T., & Kulbe, A. (2001). Spectrofluorometric characterization of dissolved organic matter for indication of precursor organic material and aromaticity. Limnology and Oceanography, 46(1), 38-48.

[33] Mladenov, N., Bigelow, A., Pietruschka, B., Palomo, M., & Buckley, C. (2017). Using submersible fluorescence sensors to track the removal of organic matter in decentralized wastewater treatment systems (DEWATS) in real time. Water Science and Technology, 77(3), 819-828.

[34] Murphy, K. R., Stedmon, C. A., Graeber, D., & Bro, R. (2013). Fluorescence spectroscopy and multi-way techniques. PARAFAC Analytical Methods, 5(23), 6557-6566.

[35] Murphy, K. R., Stedmon, C. A., Waite, T. D., & Ruiz, G. M. (2008). Distinguishing between terrestrial and autochthonous organic matter sources in marine environments using fluorescence spectroscopy. Marine Chemistry, 108(1–2), 40-58.

[36] Ni, M., & Li, S. (2022). Dynamics and internal links of dissolved carbon in a karst river system: Implications for composition, origin and fate. Water Research, 226, 119289.

[37] Ni, M., & Li, S. (2023). Ultraviolet humic-like component contributes to riverine dissolved organic matter biodegradation. Journal of Environmental Sciences (China), 124, 165-175.

[38] Ni, M. F., & Li, S. Y. (2020). Optical properties as tracers of riverine dissolved organic matter biodegradation in a headwater tributary of the Yangtze. Journal of Hydrology, 582, 124497.

[39] Niu, C., Zhang, Y., Zhou, Y., Shi, K., Liu, X., & Qin, B. (2014). The potential applications of real-time monitoring of water quality in a large shallow lake (Lake Taihu, China) using a chromophoric dissolved organic matter fluorescence sensor. Sensors (Basel, Switzerland), 14(7), 11580-11594.

[40] Osburn, C. L., Wigdahl, C. R., Fritz, S. C., & Saros, J. E. (2011). Dissolved organic matter composition and photoreactivity In prairie lakes of the U.S. Great Plains. Limnology and Oceanography, 56(6), 2371-2390.

[41] Philibert, M., Luo, S., Moussanas, L., Yuan, Q., Filloux, E., Zraick, F., & Murphy, K. R. (2022). Drinking water aromaticity and treatability is predicted by dissolved organic matter fluorescence. Water Research, 220, 118592.

[42] Ren, W., Wu, X., Ge, X., Lin, G., Zhou, M., Long, Z., Yu, X., & Tian, W. (2021). Characteristics of dissolved organic matter in lakes with different eutrophic levels in southeastern Hubei Province, China. Journal of Oceanology and Limnology 39(4), 1256-1276.

[43] Reynolds, D. M. (2002). The differentiation of biodegradable and non-biodegradable dissolved organic matter in wastewaters using fluorescence spectroscopy. Journal of Chemical Technology and Biotechnology, 77(8), 965-972.

[44] Smith, V. H., Tilman, G. D., & Nekola, J. C. (1999). Eutrophication: Impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems. Environmental Pollution (Barking, Essex: 1987), 100(1–3), 179-196.

[45] Stedmon, C. A., & Bro, R. (2008). Characterizing dissolved organic matter fluorescence with parallel factor analysis: A tutorial. Limnology and Oceanography: Methods, 6(11), 572-579.

[46] Wang, K., Pang, Y., He, C., Li, P., Xiao, S., Sun, Y., Pan, Q., Zhang, Y., Shi, Q., & He, D. (2019). Optical and molecular signatures of dissolved organic matter in Xiangxi Bay and mainstream of Three Gorges Reservoir, China: Spatial variations and environmental implications. The Science of the Total Environment, 657, 1274-1284.

[47] Wang, X., Zhang, F., Kung, H., Ghulam, A., Trumbo, A. L., Yang, J., Ren, Y., & Jing, Y. (2017). Evaluation and estimation of surface water quality in an arid region based on EEM-PARAFAC and 3D fluorescence spectral index: a case study of the Ebinur Lake Watershed, China, (Vol. 155, pp. 62–74). Elsevier BV.

[48] Wei, H., Yu, H., Pan, H., & Gao, H. (2018). Application of UV-visible absorption spectroscopy combined with two-dimensional correlation for insight into DOM fractions from native halophyte soils in a larger estuarine delta. Environmental Science and Pollution Research, 25(14), 14197-14205.

[49] Xenopoulos, M. A., Barnes, R. T., Boodoo, K. S., Butman, D., Catalán, N., D'Amario, S. C., Fasching, C., Kothawala, D. N., Pisani, O., & Solomon, C. T. (2021). How humans alter dissolved organic matter composition in freshwater: Relevance for the Earth's biogeochemistry. Biogeochemistry, 154(2), 323-348.

[50] Yang, X., Zhou, Y., Yang, X., Zhang, Y., Spencer, R., Brookes, J. D., Jeppesen, E., Zhang, H., & Zhou, Q. (2024). Optical measurements of dissolved organic matter as proxies for COD_Mn and BOD₅ in plateau lakes. Environmental Science and Ecotechnology, 19(19), 100326.

[51] Zhang, L. Q., & Li, S. Y. (2024). Anthropogenic DOM accumulation fuels greenhouse gas diffusion in urban lakes along trophic gradient. Process. Saf. Environ, 186, 474-485.

[52] Zhang, L. Q., Xu, Y. J., & Li, S. Y. (2023a). Changes in CO₂ concentration and degassing of eutrophic urban lakes associated with algal growth and decline. Environmental Research, 237, 117031.

[53] Zhang, L. Q., Xu, Y. J., & Li, S. Y. (2023b). Source and quality of dissolved organic matter in streams are reflective to land use/land cover, climate seasonality and pCO₂. Environmental Research, 216, 114608.

[54] Zhang, Y., van Dijk, M. A., Liu, M., Zhu, G., & Qin, B. (2009). The contribution of phytoplankton degradation to chromophoric dissolved organic matter (CDOM) in eutrophic shallow lakes: Field and experimental evidence. Water Research, 43(18), 4685-4697.

[55] Zhang, Y., Yin, Y., Feng, L., Zhu, G., Shi, Z., Liu, X., & Zhang, Y. (2011). Characterizing chromophoric dissolved organic matter in Lake Tianmuhu and its catchment basin using excitation-emission matrix fluorescence and parallel factor analysis. Water Research, 45(16), 5110-5122.

[56] Zhang, Y., Zhang, E., Yin, Y., Van Dijk, M. A., Feng, L., Shi, Z., Liu, M., & Qin, B. (2010). Characteristics and sources of chromophoric dissolved organic matter in lakes of the Yungui Plateau, China, differing in trophic state and altitude. Limnology and Oceanography, 55(6), 2645-2659.

[57] Zhang, Y., Zhou, Y., Shi, K., Qin, B., Yao, X., & Zhang, Y. (2018). Optical properties and composition changes in chromophoric dissolved organic matter along trophic gradients: Implications for monitoring and assessing lake eutrophication. Water Research, 131, 255-263.

[58] Zhang, Y., Zhu, G., Qin, B., Zhou, Y., & Shi, K. (2020). Application feasibility of chromophoric dissolved organic matter (CDOM) absorption coefficient as the substitute for chemical oxygen demand concentration in lakes and reservoirs. Journal of Lake Sciences 32(6), 1575-1584.

[59] Zhou, Y., Song, K., Han, R., Riya, S., Xu, X., Yeerken, S., Geng, S., Ma, Y., & Terada, A. (2020). Nonlinear response of methane release to increased trophic state levels coupled with microbial processes in shallow lakes. Environmental Pollution (Barking, Essex: 1987), 265, 114919.

[60] Zhou, Y., Zhang, Y., Jeppesen, E., Murphy, K. R., Shi, K., Liu, M., Liu, X., & Zhu, G. (2016). Inflow rate-driven changes in the composition and dynamics of chromophoric dissolved organic matter in a large drinking water lake. Water Research, 100, 211-221.

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2025 The Author(s). River published by Wiley-VCH GmbH on behalf of China Institute of Water Resources and Hydropower Research (IWHR).