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.
Anaerobic ammonium oxidation（ ANAMMOX） is an important nitrogen removal pathway which differs from denitrification and can concurrently transform ammonium and nitrite to N2 in sedimentary environments. In this study,with the slurry incubation experiment,ANAMMOX rate and the contribution to the nitrogen loss in the sediments at west Taihu Lake in four seasons were quantitatively investigated with15 N-labeled NH＋4 and NO-3 based on isotope pairing technique. The seasonal variations of the potential ANAMMOX rate and the causes were discussed based on the abundance of ANAMMOX functional genes and the physico-chemical characteristics of the sediments. The main findings were as follows. The ANAMMOX rates varied significantly with seasons,higher in summer and autumn. The total nitrogen loss rate in the sediments ranged from 10. 67 μmol·kg^-1·h^-1 to 31. 02μmol·kg^-1·h^-1. ANAMMOX played a key role in the nitrogen loss process and accounted for 30% to 40% of the total N2 production. Ammonium,organic matter and ANAMMOX functional genes were closely related to potential ANAMMOX rate. The concentration of ammonium in sediment pore water and the abundance of ANAMMOX functional genes were higher while the contents of organic matter in sediments were lower in summer and autumn than those in spring and winter. The potential ANAMMOX rate exhibited a positive correlation with the concentration of ammonium in pore water and the abundance of ANAMMOX functional genes,and exhibited a negative correlation with the content of organic matter in the sediments.
作者
罗跃辉
阮晓红
李荣富
张亚平
LUO Yuehui RUAN Xiaohong LI Rongfu ZHANG Yaping(Key Laboratory of Surficial Geochemistry, Ministry of Education, Nanjing University, Nanjing 210023 School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023)
出处
《环境科学学报》
CAS
CSCD
北大核心
2017年第11期4187-4194,共8页
Acta Scientiae Circumstantiae
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)~~
关键词
厌氧氨氧化
同位素配对技术
潜在速率
影响因子
太湖西部湖区
anaerobic ammonium oxidation
isotope pairing technique
potential ANAMMOX rate
influencing factors
west Taihu Lake
