The impact of water-sediment regulation scheme (WSRS) on the chemistry of dissolved organic matter in the Yellow River estuary and adjacent waters

作者：Donglei Niu, Yanfang Li, Yang Tan, Chao Ma, Yulin Qi, Yanan Li, Jianhui Tang · 发表于：Water Research · 年份：2025 · DOI：10.1016/j.watres.2025.123669 · 被引用次数：21 · 研究领域：Marine and coastal ecosystems、Coastal and Marine Management、Microbial Community Ecology and Physiology

Dissolved organic matter (DOM) plays important roles in the global carbon cycle and aquatic ecosystem health. Estuaries are critical zones connecting land and ocean in which DOM experiences dispersion, transformation, degradation, deposition, etc. The Water-sediment regulation scheme (WSRS) was implemented in Yellow River (YR) and approximately half of annually sediment and a quarter of annually water were poured into estuary in around 20 days. Meanwhile, huge amounts of DOM were discharged into Yellow River estuary (YRE) rapidly, but their processes and fates in YRE and adjacent seas are unclear. This study aims to investigate the molecular and spectrum compositions of DOM and its associated transformation mechanisms around the YRE and its adjacent sea before (from June 8 to 12, 2022) and after (from July 18 to 22, 2022) the WSRS. A relatively greater amount of highly unsaturated compounds and terrestrial-derived DOM was found with higher aromaticity and humification degree after WSRS, by bulk geochemical techniques, optical spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) techniques. High levels of less photodegraded DOM were found in the estuarine region after WSRS, due to the rapidly pouring huge amount of fresh water and sediment into YRE. The high suspended sediment concentration facilitates the sorption of dissolved organic carbon (DOC), especially those sulphur-containing compounds in DOM which decreased both in the relative int...