北运河上覆水DOM分子组成和结构特征

利用高分辨傅里叶变换离子回旋共振质谱技术(FT-ICR-MS)及分析手段综合表征了北运河上覆水中DOM分子组成和结构特征,揭示了DOM分子组成的迁移转化规律,并评估了DOM分子组成的潜在环境影响。结果表明:北运河上覆水DOM分子化合物主要由木质素(63.19%)和蛋白质(12.96%)组成。上覆水中稳定DOM分子公式主要由难降解木质素和不断循环且再生的基本代谢物及分泌物组成,独特DOM分子公式的多样性与人为活动强度有关,优先被转化或降解的相同DOM分子公式主要为携带高化学活性羧基和羟基的木质素和不稳定的脂质、蛋白质和碳水化合物。北运河具有外源废水输入量高的特点,致使上覆水具有大量不稳定DOM化合物,增加了河流富营养化的潜在风险。

Compositional and structural characteristics of DOM molecules in the overlying water of the Beiyun River

FT-ICR-MS technology and analytical methods were used to comprehensively characterize the compositional and structural characteristics of DOM molecules in the overlying water of the Beiyun River, revealing the migration and transformation rules of DOM molecular composition and evaluating the potential environmental impact of DOM molecular composition. The results indicated that the DOM molecular compounds in the overlying water of the Beiyun River were mainly composed of lignin (63.19%) and proteins (12.96%). The stable DOM molecular formulas in the overlying water were mainly refractory lignin and basic metabolites and secretions that are continuously recycled and regenerated. The diversity of unique DOM molecular formulas correlated with intensity anthropogenic activities. The common DOM molecular formula that was preferentially transformed or degraded was mainly lignin with highly chemically active carboxyl and hydroxyl groups and liable lipids, proteins and carbohydrates. The Beiyun River had the characteristics of high input of exogenous wastewater, resulting in a large amount of liable DOM compounds in the overlying water, which increased the potential risk of river eutrophication.