| 太湖春夏两季反硝化与厌氧氨氧化速率的空间差异及其影响因素 |
| 摘要点击 2336 全文点击 693 投稿时间：2020-08-30 修订日期：2020-11-03 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 反硝化 厌氧氨氧化 太湖 硝酸盐 脱氮速率 |
| 英文关键词 denitrification ANAMMOX Lake Taihu nitrate nitrogen removal rates |
|
| 中文摘要 |
| 反硝化和厌氧氨氧化是湖泊的重要脱氮过程，对维持湖泊氮素平衡具有重要意义.为了解大型富营养化浅水湖泊——太湖反硝化和厌氧氨氧化速率的时空变化及其影响因素，于2020年春季和夏季选择太湖的梅梁湾、贡湖湾、竺山湾、大浦口、胥口湾和湖心区采集无扰动泥柱，利用15N同位素示踪技术，在恒温水浴条件下开展反硝化和厌氧氨氧化流动培养实验.结果表明，春季太湖不同湖区反硝化和厌氧氨氧化速率的空间分布差异较大，反硝化速率为（27.74±8.45）~（142.43±35.54）μmol·（m2·h）-1，厌氧氨氧化速率为（2.35±1.06）~（17.95±8.66）μmol·（m2·h）-1，厌氧氨氧化对脱氮的贡献率相对较低，为（7.82±1.71）%~（11.20±1.53）%.夏季竺山湾脱氮速率最高，反硝化和厌氧氨氧化速率分别高达（165.68±62.14）μmol·（m2·h）-1和（33.56±10.66）μmol·（m2·h）-1，厌氧氨氧化对脱氮贡献率达到了（16.85±1.78）%，其他湖区的脱氮速率相对较低，且没有十分显著的空间差异，反硝化和厌氧氨氧化速率分别为（25.47±10.46）~（42.50±16.46）和（2.65±0.94）~（5.95±2.65）μmol·（m2·h）-1，厌氧氨氧化对脱氮的贡献率为（13.62±1.95）%~（7.24±1.78）%.总体来说，夏季反硝化速率要普遍低于春季，而厌氧氨氧化速率相对于春季并无明显下降.统计分析表明，反硝化和厌氧氨氧化速率与底物氮浓度呈显著的相关性（P<0.01），说明氮浓度是不同湖区脱氮速率差异的主要控制因素.此外，厌氧氨氧化对脱氮的贡献率与叶绿素a的浓度呈现显著的正相关性（P<0.05），说明蓝藻水华对厌氧氨氧化脱氮贡献率的变化有很大的影响，具体的影响机制还有待进一步研究. |
| 英文摘要 |
| Denitrification and ANAMMOX are the main nitrogen removal processes in lakes, which are of great significance for maintaining the nitrogen balance. Lake Taihu is a large, shallow lake. There are great spatial and temporal differences in the nutrient levels and algal blooms, which will affect the rates of denitrification and ANAMMOX. In order to understand the spatial and temporal variations in the denitrification and ANAMMOX rates and their influencing factors in Lake Taihu, undisturbed sediment cores were collected from Meiliang Bay, Gonghu Bay, Zhushan Bay, Dapukou Bay, Xukou Bay, and the center of Lake Taihu in the spring and summer of 2020. The results showed that the spatial distribution of the denitrification and ANAMMOX rates varied greatly in different areas of Lake Taihu in spring. The denitrification and ANAMMOX rates were (27.74±8.45)-(142.43±35.54) μmol·(m2·h)-1 and (2.35±1.06)-(17.95±8.66) μmol·(m2·h)-1, respectively. The contribution of ANAMMOX to nitrogen removal was relatively low, ranging from (7.82±1.71)% to (11.20±1.53)%. In summer, the denitrification and ANAMMOX rates were (165.68±62.14) μmol·(m2·h)-1 and (33.56±10.66) μmol·(m2·h)-1, respectively. The nitrogen removal rates were relatively low in other areas where the denitrification and ANAMMOX rates were (25.47±10.46)-(42.50±16.46) μmol·(m2·h)-1 and (2.65±0.94)-(5.95±2.65) μmol·(m2·h)-1, respectively. The contribution of ANAMMOX to nitrogen removal was (13.62±1.95)%-(7.24±1.78)%. The denitrification rate in summer was generally lower than that in spring, while the ANAMMOX rate did not decrease significantly compared with that in spring. The statistical analysis showed that the denitrification and ANAMMOX rates were significantly correlated with the substrate nitrogen concentration (P<0.01), which indicated that the nitrogen concentration was the main factor causing the difference in the nitrogen removal rates in different lake regions. In addition, there was a significant positive correlation between the contribution rate of ANAMMOX and the concentration of chlorophyll-a (P<0.05), thereby indicating that cyanobacteria blooms have a great influence on the change in the contribution of ANAMMOX to nitrogen removal. |
|
|
|
