干湿交替对自然沟渠沉积物反硝化速率的影响  

Effect of wet and dry alternation on denitrification in natural ditch sediments

作　　者：邵志江 汪涛[1] 张云霞 郑斌 SHAO Zhijiang;WANG Tao;ZHANG Yunxia;ZHENG Bin(Institute of Mountain Hazards and Environment,Chinese Academy of Science,Chengdu 610041;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院水利部成都山地灾害与环境研究所,成都610041 [2]中国科学院大学,北京100049

出　　处：《环境科学学报》2020年第11期4010-4017,共8页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2017YFD0800105);四川省环境治理与生态保护重大科技专项(No.2018SZDZX0025);国家自然科学基金(No.41371462)。

摘　　要：以川中丘陵区自然沟渠沉积物为研究对象,设置低强度、中强度、高强度的干湿交替频率和长期淹水对照处理,运用室内原状土柱⁃乙炔抑制培养法和实时荧光定量PCR技术,研究了干湿交替对自然沟渠沉积物反硝化速率及相关功能基因的影响.结果表明:在试验模拟过程中,干湿交替显著降低了沉积物中NH+4⁃N和DOC含量,沉积物中NO-3⁃N含量则表现为先增加后减少的趋势.沉积物反硝化速率均值表现为中强度(266.42μg·m-2·h-1)>高强度(199.10μg·m-2·h-1)>低强度(152.93μg·m-2·h-1)>长期淹水(9.57μg·m-2·h-1).干湿交替增加了反硝化功能基因的拷贝数(p<0.05),nosZ基因拷贝数在实验前后无显著差异;低强度和中强度处理的nirK基因拷贝数在实验前后差异显著,中强度处理的nirS基因拷贝数在实验前后差异显著.Pearson相关分析结果表明,沉积物的反硝化速率与NO-3⁃N含量、ORP和nirK基因拷贝数呈显著正相关(p<0.05).干湿交替可能主要通过改变沉积物的NO-3⁃N含量、ORP和nirK基因拷贝数影响沉积物反硝化速率.The effect of alternating dry and wet conditions on the denitrification rate and related functional genes in natural trench sediments were investigated by conducting three experimental treatments of the low⁃intensity,medium⁃intensity,high⁃intensity dry⁃wet alternating frequency and the control of long⁃term flooding control with indoor undisturbed soil column⁃acetylene suppression culture method and real⁃time PCR technology.The results showed that the alternation of wet and dry significantly decreased the contents of NH+4⁃N and DOC in the sediment,and the contents of NO-3⁃N in the sediment with a trend of increasing first and then decreasing during the experiment simulation.The mean value of sediment denitrification rates for different wet and dry alternation have the following pattern,i.e.medium intensity(266.42μg·m-2·h-1)>high intensity(199.10μg·m-2·h-1)>low intensity(152.93μg·m-2·h-1)>Long-term flooding(9.57μg·m-2·h-1).Alternating dry and wet increased the copy number of the denitrification function gene(p<0.05),but no differences in nosZ gene between before and after the experiment;the significant difference in nirK gene between before and after the experiment of treatment were low⁃intensity and medium⁃intensity;the significant difference in nirS gene between before and after the experiment of treatment was medium⁃intensity.Pearson correlation analysis results showed that the denitrification rates of sediments were positively correlated with NO-3⁃N content,ORP and nirK(p<0.05).Dry⁃wet alternation could affect the denitrification rate of sediment mainly through regulating the NO-3⁃N content of the sediment,ORP and nirK gene copy number.

关 键 词：干湿交替 自然沟渠 反硝化速率 沉积物 反硝化功能基因 

分 类 号：X171[环境科学与工程—环境科学]