Publications by authors named "Ying-Xun Du"
Article Synopsis
- * Results showed that DOM from both sources converged in composition under combined treatment, with microbial processes being more crucial for algal DOM and phototransformation for terrestrial DOM.
- * Complex interactions between DOM molecules and bacteria were more pronounced with terrestrial DOM, indicating that transforming this type of DOM requires greater bacterial collaboration compared to algal DOM.
Dissolved organic matter (DOM) is a heterogeneous pool of compounds and exhibits diverse adsorption characteristics with or without phosphorous (P) competition. The impacts of these factors on the burial and mobilization of organic carbon and P in aquatic ecosystems remain uncertain. In this study, an algae-derived DOM (ADOM) and a commercially available humic acid (HA) with distinct compositions were assessed for their adsorption behaviors onto iron (oxy)hydroxides (FeOx), both in the absence and presence of phosphate.
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- Climate change is causing alpine lake environments to become subalpine lakes, which leads to increased vegetation due to warmer temperatures and higher precipitation levels.
- Terrestrial dissolved organic matter (TDOM) from surrounding soils in these lakes undergoes significant changes due to strong sunlight and microbial activities, affecting both the composition of organic matter and the bacterial communities present.
- A study at Lake Tiancai revealed that sunlight drastically increased the diversity of TDOM while shaping bacterial communities, indicating important implications for the carbon cycle and the overall health of lake ecosystems in response to climate change.
Article Synopsis
- Algal-dissolved organic matter (ADOM) is a crucial part of dissolved organic carbon in nutrient-rich waters, influenced by microbial and sunlight-induced processes.
- In a study lasting 18 days, three treatment methods were tested: light exposure (L), microbial activity (M), and a combination of both (L&M), with varying effectiveness on the breakdown of organic compounds.
- Results indicated that microbial processes were better at removing dissolved organic carbon, while sunlight was more effective in altering specific fluorescent components, and the combination of both processes affected the decay rate of organic matter differently.
Article Synopsis
- - The stability of organic matter-iron-phosphate (OM-Fe-P) associations is crucial for understanding how organic carbon (OC) and phosphorus (P) move and are stored in the environment.
- - The study explored how the abiotic reduction of these associations using Na-dithionite affects the release of iron (Fe), P, and organic matter (OM), finding that adsorbed OM and P are released quickly, while coprecipitated forms release them more slowly.
- - Results showed that the type of organic matter used (algae-derived vs. terrestrial humic acid) and the method of association formation significantly influenced release rates, with coprecipitated associations being more stable and having a different distribution of
Article Synopsis
- Color dissolved organic matter (CDOM) in lakes is influenced by both external (allochthonous) inputs and internal (autochthonous) production, significantly affecting its composition and cycling.
- A study was conducted in Lake Fuxian, China, to analyze CDOM during the wet season and compare its characteristics with other lakes, revealing that riverine CDOM had higher levels of humic-like substances while Lake Fuxian's CDOM was mainly protein-like.
- The findings showed that although CDOM composition varied across various lakes, the quantity increased significantly in deeper lakes with well-vegetated catchments, suggesting that allochthonous inputs impact CDOM but can be moderated by in-lake processing dynamics.
Article Synopsis
- Shallow lakes can be dominated by either macrophytes or algae, which leads to distinct types of organic matter (OM) in their sediments that affect carbon storage and processing.
- A study compared sediments from Taihu Lake's macrophyte-dominated (East Taihu Lake) and algae-dominated zones (Meiliang Bay), using various spectroscopic techniques to analyze the water-soluble organic matter (WSOM).
- Results indicated that the WSOM from the macrophyte zone had larger molecular sizes and higher humification levels compared to the algae zone, while there was a greater presence of protein-like substances in the algae-dominated sediments.
Article Synopsis
- The study investigates how organic matter (OM) generated from phytoplankton growth during algal blooms impacts the carbon cycle, particularly in shallow eutrophic lakes like Lake Chaohu in China.
- It compares two experimental treatments: one with sediments and one without, revealing that sediments significantly influenced the concentrations of biogenic elements, resulting in much higher levels of chlorophyll a, nutrients, and metals in the presence of sediments.
- The results suggest that while particulate organic matter (POM) is dominated by protein-like components and has lower molecular weight, dissolved organic matter (DOM) becomes more abundant afterward and features higher molecular weight and humic-like components, indicating a complex transformation process influenced by sediment.
Humic acid (HA) and phosphate interactions play a vital role in the biogeochemical cycle of carbon and nutrients and thus the trophic state of a lake. The adsorption behavior of HAs to sediments in the absence and presence of phosphate was investigated in this study. Three types of HAs were used, AHA from algae-dominated lake sediments, MHA from macrophyte-dominated lake sediments, and a reference HA (RHA) with terrestrial sources.
View Article and Find Full Text PDFAgricultural land use leads to significant changes in both the quality (e.g., sources and compositions) and quantity of dissolved organic matter (DOM) exported from terrestrial to aquatic ecosystems.
View Article and Find Full Text PDF[Biodegradation of Algae-derived Organic Matter (I-DOM) from Lake Taihu].
Huan Jing Ke Xue
April 2021
A large amount of intracellular dissolved organic matter (I-DOM) is released during the senescent phase of phytoplankton cultures. This research investigated the bio-incubation of I-DOM of cyanobacteria in Lake Taihu under various temperatures (20, 25, and 30℃) and I-DOM initial concentrations (5, 10, and 20 mg·L) with the aid of ultraviolet-visible spectroscopy (UV-Vis) and three-dimensional fluorescence matrix-parallel factor (EEM-PARAFAC). I-DOM was effectively degraded during the incubation.
View Article and Find Full Text PDFHuman activities can alter dissolved organic matter (DOM) in lakes through both direct (i.e., exporting DOM of anthropogenic sources) and indirect effects (i.
View Article and Find Full Text PDFHuman land use has led to significant changes in the character of dissolved organic matter (DOM) in lotic ecosystems. These changes are expected to have important environmental and ecological consequences. However, high spatiotemporal variability has been reported in previous studies, and the underlying mechanisms remain inadequately understood.
View Article and Find Full Text PDFIn this study, N-doped Ta2O5 samples which have strong absorption in visible domain, were prepared by the nitridation of Ta2O5 under NH4 flow and then added into photo-Fenton-like system to enhance Fe3+ reduction and atrazine degradation under visible light irradiation. The sample prepared at 700 degrees C under a NH3 flow rate of 0.3 L x min(-1) for 6 h showed the highest level of photocatalytic activity for Fe3+ reduction.
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