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Cladophora is commonly found in marine and freshwater around the globe and provides productivity for littoral zone microorganisms and invertebrates. The eutrophication of the water body has led to the abnormal proliferation of Cladophora in some water, often in river coast channel outbreaks. Even under the nutritional deficiency systems, such as the central trunk canal of the South-to-North Water Diversion in China, Cladophora's blooms affect water quality and seriously jeopardize human health. Thus, the structural characteristics of Cladophora cells and spores, the factors affecting the growth of Cladophora cells, and the mechanisms of damage and destruction of Cladophora cells and spores were investigated. Cladophora cells are cylindrical with very thick cell walls. The inner layer of the spore wall is a thin membrane which contains the nucleus of the spore. The growth and spreading of Cladophora cells are affected by various environmental factors such as light, temperature, water depth, water level, nutrient salts, pH, etc. Some physical treatment measures, such as ultrasounds, would destroy the cell walls and membranes of Cladophora by its high-intensity mechanical action. Chemicals and aquatic plant measures can destroy Cladophora cells' photosynthesis system, antioxidant enzyme systems, proteins, and ultrastructure. Based on the mechanisms for these cell damage and destruction, a combination of measures that are likely to inhibit the growth of Cladophora cells effectively was suggested. Furthermore, the damaged cells of Cladophora could provide some environmental benefits. Aggregated results could provide a scientific basis for further research on the control of blooms of Cladophora or the reuse of Cladophora cells as a natural resource. [ABSTRACT FROM AUTHOR]

The characterization of dissolved organic matter (DOM) is important for better understanding of the migration and transformation mechanisms of DOM in water bodies and its interaction with other contaminants. In this work, fluorescence characteristics and molecular compositions of the DOM samples collected from the mainstream, tributary, and sewage outfall of the Inner Mongolia section of the Yellow River (IMYR) were determined by using fluorescence spectroscopy and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). In addition, concentrations of potentially toxic elements (PTEs) in the relevant surface water and their potential relationships with DOM were investigated. The results showed that the abundance of tyrosine-like components increased significantly in downstream waters impacted by outfall effluents and was negatively correlated with the humification index (HIX). Compared to the mainstream, outfall and tributaries have a high number of molecular formulas and a higher proportion of CHOS molecular formulas. In particular, the O5S class has a relative intensity of 41.6% and the O5-7S class has more than 70%. Thirty-eight PTEs were measured in the surface water samples, and 12 found above their detective levels at all sampling sites. Protein-like components are positively correlated with Cu, which is likely indicating the source of Cu in the aquatic environment of the IMYR. Our results demonstrated that urban wastewater discharges significantly alter characteristics and compositions of DOM in the mainstream of IMYR with strongly anthropogenic features. These results and conclusions are important for understanding the role and sources of DOM in the Yellow River aquatic environment. [ABSTRACT FROM AUTHOR]