太湖西部湖区沉积物厌氧氨氧化潜在速率及其脱氮贡献研究

发布时间：2018-04-15 02:03

本文选题：厌氧氨氧化 + 同位素配对技术　；参考：《环境科学学报》2017年11期

【摘要】：厌氧氨氧化作为一种异于反硝化的氮转化途径,可同时将氨氮与亚硝氮转化为氮气,是沉积环境中重要的脱氮过程.本文基于15N同位素配对技术,利用15NH+4、15NH+4+14NO-3和15NO-3三组同位素开展泥浆培养试验,研究了四季太湖西部湖区沉积物厌氧氨氧化潜在速率及其脱氮贡献率;结合厌氧氨氧化功能基因丰度及沉积物理化特征,探讨了沉积物厌氧氨氧化潜在速率季节性差异的成因.研究结果表明:沉积物厌氧氨氧化潜在速率存在显著的季节差异性,夏、秋季显著高于春、冬季,秋季最高,为10.11μmol·kg-1·h-1(以N2计,下同),冬季最低,为3.24μmol·kg-1·h-1;沉积物总脱氮速率为10.67~31.02μmol·kg-1·h-1,其中厌氧氨氧化脱氮效应显著,四季脱氮贡献率高达30%~40%.有机质、氨氮及其功能基因丰度是影响厌氧氨氧化潜在速率的重要因子,研究区域沉积物孔隙水夏、秋季氨氮浓度和厌氧氨氧化功能基因丰度均高于春、冬季,沉积物有机质含量低于春、冬季,厌氧氨氧化潜在速率随沉积物孔隙水氨氮及其功能基因丰度升高而升高,随沉积物有机质升高而降低.
[Abstract]:Anaerobic ammonia oxidation is an important denitrification process, which can transform ammonia nitrogen and nitrite nitrogen into nitrogen gas, which is different from denitrification.Based on 15N isotope matching technique, mud culture experiments were carried out by using 15NH 4N 15NH 4 14NO-3 and 15NO-3 isotopes to study the potential rate of anaerobic ammonia oxidation and the nitrogen removal contribution rate of sediments in the West Lake area of the four Seasons Taihu Lake.Combined with the abundance of anaerobic ammonia oxidation function gene and the physical and chemical characteristics of sediment, the cause of seasonal difference of potential rate of anaerobic ammonia oxidation in sediments was discussed.The results showed that the potential rate of anaerobic ammonia oxidation in sediment was significantly different in seasons, and was significantly higher in summer and autumn than in spring, winter and autumn, with the highest value of 10.11 渭 mol kg-1 h-1 in N _ 2, and the lowest in winter.The total denitrification rate of sediment is 10.67 ~ 31.02 渭 mol kg-1 h-1, and the effect of anaerobic ammonia oxidation denitrification is significant, and the contribution rate of denitrification in four seasons is as high as 30 ~ 40%.The abundance of organic matter, ammonia nitrogen and its functional genes were the important factors affecting the potential rate of anaerobic ammonia oxidation. The concentration of ammonia nitrogen and the abundance of the functional genes of anaerobic ammonia oxidation in summer, autumn and autumn were all higher than those in spring and winter.The content of organic matter in sediment was lower than that in spring. In winter, the potential rate of anaerobic ammonia oxidation increased with the increase of abundance of ammonia nitrogen and its functional genes in pore water, and decreased with the increase of organic matter in sediment.
【作者单位】：南京大学表生地球化学教育部重点实验室;南京大学地球科学与工程学院;
【基金】：国家自然科学基金重点基金(No.41230640) 江苏省水利科技项目(No.2016022)~~
【分类号】：X524

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