Insight into transformation of dissolved organic matter in the Heilongjiang River
- 693 Downloads
Heilongjiang is a “browning” river that receives substantial terrestrial organic matter, where reactivity of dissolved organic matter (DOM) may have important effect on ecosystem function and carbon biogeochemical cycle. However, little is known about microbial transformations of different DOM components, which could provide valuable insight into biogeochemical reactivity of DOM. In this study, bioavailability experiments were conducted for 55 days to determine changes of different DOM components by microbial transformations. Labile matter (C1) was detected only in initial DOM, and tryptophan-like substances (C4) were observed from day 5 onwards. Thus, three individual components were identified at each sampling time of the bioavailability experiment. The increase of Fmax in DOM components revealed that microbial humic-like substances (C2), terrestrial humic-like substances (C3), and C4 were produced by microbial transformation, especially in the spring samples. Further, two-dimensional correlation spectroscopy (2D-COS) indicated that shorter wavelength tryptophan-like and microbial humic-like substances can be degraded by microbes or transformed into longer wavelength complex substances. Relatively simple microbial humic-like substances were preferentially produced compared to complex terrestrial humic-like substances. The results make sense to understand the biogeochemical cycling and environmental effects of DOM in the Heilongjiang River.
KeywordsHeilongjiang River Dissolved organic matter Components transformation Parallel factor analysis Generalized two-dimensional correlation spectroscopy Two-dimensional hetero-spectral correlation spectroscopy
This work was financially supported by the Major Projects on Control and Rectification of Water Body Pollution (2009ZX07106-001) and the Projects on Control and Rectification of Water Body Pollution—the Cross-border Aquatic Environment Investigation and Policy Research (2039001001011).
- Coble PG, Del Castillo CE, Avril B (1998) Distribution and optical properties of CDOM in the Arabian Sea during the 1995 southwest monsoon. Deep-Sea Res II 45: 2195–2223Google Scholar
- He XS, Xi BD, Li WT, Gao RT, Zhang H, Tan WB, Huang CH (2015) Insight into the composition and evolution of compost-derived dissolved organic matter using high-performance liquid chromatography combined with Fourier transform infrared and nuclear magnetic resonance spectra. J Chromatogr A 1420:83–91CrossRefGoogle Scholar
- Jiang T, Chen X, Wang D, Liang J, Bai W, Zhang C, Wang Q, Wei S (2018) Dynamics of dissolved organic matter (DOM) in a typical inland lake of the three gorges reservoir area: fluorescent properties and their implications for dissolved mercury species. J Environ Manag 206:418–429CrossRefGoogle Scholar
- Shi JH, Cui HY, Jia LM, Qiu LL, Zhao Y, Wei ZM, Wu JQ, Wen X (2016) Bioavailability of riverine dissolved organic carbon and nitrogen in the Heilongjiang watershed of northeastern China. Environ Monit Assess 188(113):1–9Google Scholar