Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, PR China.
Chemosphere. 2024 Apr;354:141718. doi: 10.1016/j.chemosphere.2024.141718. Epub 2024 Mar 13.
Metalimnetic oxygen minimum (MOM) occurs in reservoirs or lakes due to stratification and algal blooms, which has low dissolved oxygen (DO) levels and leads to the deterioration of water quality. The transformation mechanism and the impact on the water quality of intracellular organic matter (IOM) derived from algae are poorly understood under MOM conditions. In this study, IOM extracted by Microcystis aeruginosa was divided into five components according to molecular weight (MW), and the changes of characteristics and correlated disinfection by-products formation potential (DBPFP) were analyzed and compared under MOM conditions. The removal efficiency of dissolved organic carbon (DOC) in the <5 kDa fraction (66.6%) was higher than that in the >100 kDa fraction (41.8%) after a 14-day incubation under MOM conditions. The same tendency also occurred in Fmax and DBPFP. The decrease in Fmax was mainly due to the decline in tryptophan-like and tyrosine-like for all IOM fractions. The diversity of microorganisms degrading the MW > 100 kDa fraction was lower than others. Besides low MW fractions, these findings indicated that more attention should be paid to high MW fractions which were resistant to biodegradation under MOM conditions during water treatment.
由于分层和藻类大量繁殖，水库或湖泊中会出现金属缺氧（MOM）现象，其溶解氧（DO）水平较低，导致水质恶化。在 MOM 条件下，对藻类来源的细胞内有机物质（IOM）的转化机制及其对水质的影响知之甚少。在这项研究中，根据分子量（MW）将铜绿微囊藻提取的 IOM 分为五个组分，并分析和比较了在 MOM 条件下特征和相关消毒副产物生成潜力（DBPFP）的变化。在 MOM 条件下孵育 14 天后，<5 kDa 级分（66.6%）中溶解性有机碳（DOC）的去除效率高于>100 kDa 级分（41.8%）。Fmax 和 DBPFP 也出现了相同的趋势。Fmax 的降低主要是由于所有 IOM 级分中的色氨酸样和酪氨酸样物质的减少。MW>100 kDa 级分中降解微生物的多样性低于其他级分。除了低 MW 级分外，这些发现表明，在水处理过程中，应更加注意在 MOM 条件下具有抗生物降解性的高 MW 级分。
