Institute of Resources and Environment, Henan Polytechnic University, Jiaozuo, 454000, China.
Sanmenxia Aoke Chemical Co., Ltd, Sanmenxia, 472000, China.
Environ Sci Pollut Res Int. 2022 Oct;29(48):73100-73114. doi: 10.1007/s11356-022-20802-0. Epub 2022 May 27.
Amino acids are an important constituent in organic nitrogen deposition, and changes in the content of their components have a direct impact on the nitrogen input to the ecosystem. From December 2018 to November 2019, 176 precipitation samples were collected at Danjiangkou Reservoir, the source of the middle line of the South-to-North Water Diversion Project, and the variation characteristics of dissolved free amino acids (DFAA) and dissolved combined amino acids (DCAA) were analyzed. The volume-weighted value concentration ranges of DFAA and DCAA were 0.159-1.136 μmol/L and 1.603-7.044 μmol/L, respectively, and amino acids were dominated by DCAA in wet deposition. Our results showed that glutamic acid (Glu), glycine (Gly), and aspartic acid (Asp) were the dominant amino acids in both DFAA and DCAA. The concentration of DFAA was highest in winter, while the concentration of DCAA was in autumn. Dissolved total amino acids (DTAA) were insignificantly correlated with DFAA, whereas they were linearly correlated with DCAA, indicating a significant influence of agricultural activities on DTAA. The analysis of the backward trajectory of air masses showed that amino acids were mainly influenced by proximity inputs around the reservoir. The bioavailability of organic matter was higher in the southeastern of the reservoir than in the northwestern. The wet deposition flux of TDN was 14.096 kg N/ha/year, and the potential ecological impact on water bodies cannot be ignored. This study was conducted to clarify the variation characteristics of amino acids fractions in wet deposition and to provide parameters for regional assessment of amino acids wet deposition. The ecological impact of nitrogen wet deposition on water bodies will be explored to provide a basis for nitrogen pollution control and water quality protection in the middle line of the South-to-North Water Diversion Project.
氨基酸是有机氮沉降的重要组成部分，其组分含量的变化直接影响生态系统的氮输入。2018 年 12 月至 2019 年 11 月，在南水北调中线工程水源地丹江口水库采集了 176 个降水样品，分析了溶解游离氨基酸（DFAA）和溶解结合氨基酸（DCAA）的变化特征。DFAA 和 DCAA 的体积加权浓度范围分别为 0.159-1.136μmol/L 和 1.603-7.044μmol/L，湿沉降中以 DCAA 为主。结果表明，DFAA 和 DCAA 中均以谷氨酸（Glu）、甘氨酸（Gly）和天冬氨酸（Asp）为主。DFAA 浓度冬季最高，DCAA 浓度秋季最高。DFAA 与 DTAA 无显著相关性，而与 DCAA 呈线性相关，表明农业活动对 DTAA 有显著影响。气团后向轨迹分析表明，氨基酸主要受水库周边近距离输入的影响。与水库西北部相比，东南部的有机质生物可利用性更高。TDN 的湿沉降通量为 14.096kgN/ha/year，对水体的潜在生态影响不容忽视。本研究旨在阐明湿沉降中氨基酸组分的变化特征，为区域评估氨基酸湿沉降提供参数。探索氮湿沉降对水体的生态影响，为南水北调中线工程氮污染控制和水质保护提供依据。
