Zhao Yu, Shan Baoqing, Tang Wenzhong, Zhang Hong, Rong Nan, Ding Yuekui
State Key Laboratory on Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
University of Chinese Academy of Science, Beijing 100047, China.
Int J Environ Res Public Health. 2016 Feb 19;13(2):234. doi: 10.3390/ijerph13020234.
The Haihe River Basin, which is one of the most water-scarce and polluted river basins in China, has abnormally high nitrogen levels. In this study, total hydrolyzable amino acids (THAAs) were measured in surface sediment and sediment core samples in the Haihe River Basin to determine if amino acids were potential sources of ammonium, organic nitrogen, and organic carbon. The rivers were found to be in a state of hypoxia and contain abnormally high levels of ammonium and organic nitrogen. Additionally, NH₃-N was the predominant form of inorganic nitrogen in the surface sediments, while organic nitrogen accounted for 92.53% of sedimentary nitrogen. THAAs-C accounted for 14.92% of the total organic carbon, while THAAs-N accounted for more than 49.59% of organic nitrogen and 45.68% of total nitrogen. The major fraction of THAAs were protein amino acids. Three sediment cores of the most heavily polluted rivers also showed high levels of THAAs. Evaluation of the degradation index (DI) of sedimentary organic matter in sediments evaluated based on the THAAs revealed that most positive DI values were found in the downstream portion of the Ziya River Watershed. Additionally, the DI of surface sediment was correlated with THAAs (r² = 0.763, p < 0.001), as was the DI of sediment cores (r² = 0.773, p < 0.001). Overall, amino acids in sediments were found to be an important potential source of ammonium, organic nitrogen, and organic carbon.
海河流域是中国水资源最为匮乏且污染最为严重的流域之一，其氮含量异常高。在本研究中，对海河流域的表层沉积物和沉积物岩芯样本中的总水解氨基酸（THAAs）进行了测量，以确定氨基酸是否为铵、有机氮和有机碳的潜在来源。研究发现这些河流处于缺氧状态，且铵和有机氮含量异常高。此外，NH₃-N是表层沉积物中无机氮的主要形式，而有机氮占沉积氮的92.53%。THAAs-C占总有机碳的14.92%，而THAAs-N占有机氮的比例超过49.59%，占总氮的45.68%。THAAs的主要部分是蛋白质氨基酸。三条污染最严重河流的沉积物岩芯也显示出较高水平的THAAs。基于THAAs对沉积物中沉积有机物的降解指数（DI）进行评估，结果表明，大部分正DI值出现在子牙河流域的下游部分。此外，表层沉积物的DI与THAAs相关（r² = 0.763，p < 0.001），沉积物岩芯的DI也是如此（r² = 0.773，p < 0.001）。总体而言，沉积物中的氨基酸被发现是铵、有机氮和有机碳的重要潜在来源。
