摘要
为了揭示自然环境和人为活动对城市河流沉积物氮去除过程的影响,采用泥浆实验结合15N同位素示踪技术,分别测定4℃和25℃温度下海河干流沉积物反硝化和厌氧氨氧化的反应速率.结果表明:①在4℃和25℃下,沉积物反硝化速率变化范围分别为0.11~1.94 mmol N·L^(-1)·h^(-1)和0.47~2.73 mmol N·L^(-1)·h^(-1);厌氧氨氧化速率波动相对较大,变化范围分别为0.06~1.80 mmol N·L^(-1)·h^(-1)和0.28~4.14 mmol N·L^(-1)·h^(-1).25℃时2种反应的速率均明显高于低温(4℃)时的速率,表明高温(25℃)更有利于刺激反硝化和厌氧氨氧化细菌的酶活性.②沉积物中TOC、TN、NH_(4)^(+)、NO_(3)^(-)含量是影响反硝化和厌氧氨氧化反应速率的重要理化性质,海河干流下游上述参数的值高于上游的值,且都保留在河流型水库中,因此下游反硝化和厌氧氨氧化速率明显高于上游.③在4℃和25℃下,反硝化过程脱氮贡献率分别为32%和52%,厌氧氨氧化过程的脱氮贡献率分别为68%和48%.反硝化和厌氧氨氧化反应去除的氮总量分别约占输入河流总氮的21.02%和20.50%,减少了陆源氮素向河口和近岸海域的输出风险.
In order to reveal the effects of natural environment and human activities on the nitrogen removal process in urban river sediments,the denitrification and anammox reaction rates of sediments in the main stream of Haihe River at 4℃and 25℃were determined by mud experiment combined with 15N isotope tracer technology,respectively.The results showed that:①At 4℃and25℃,the denitrification rates ofsediments were 0.11-1.94 mmolN·L^(-1)·h^(-1)and 0.47-2.73 mmolN·L^(-1)·h^(-1),respectively.The rate of anammox fluctuated relatively large,with the range of 0.06-1.80 mmol N·L^(-1)·h^(-1)and 0.28-4.14 mmol N·L^(-1)·h^(-1),respectively.The rates at high temperature(25℃)were significantly higher than those at low temperature(4℃).High tempera-ture(25℃)was more conductive to stimulate the enzyme activity of denitrifying and anammox bacteria.②The content of TOC,TN,NH_(4)^(+),and NO_(3)^(-)in sediment were important physicochemical properties affecting the rate of denitrification and anammox.The content of these parameters in the downstream of the main stream of Haihe River was higher than that in the upstream,and they were all retained in river type reservoirs.Therefore,the denitrification and anammox rates in the downstream were sig-nificantly higher than those in the upstream.③At 4℃and 25℃,the contribution rates of denitrification were 32%and 52%,respectively,and the contribution rates of anammox were 68%and 48%,respectively.The total amount of nitrogen removal that can be removed through denitrification and anammox reactions accounts for about 21.02%and 20.50%of the total nitrogen in the input river,respectively,which can reduce the risk of terrestrial nitrogen export to estuaries and coastal waters.
作者
李欣容
薛冬梅
LI Xinrong;XUE Dongmei(Tianjin Key Laboratory of Water Resource and Environment,Tianjin Normal University,Tianjin 300387,China;School of Geographic and Environmental Sciences,Tianjin Normal University,Tianjin 300387,China)
出处
《天津师范大学学报（自然科学版）》
CAS
北大核心
2024年第2期50-55,68,共7页
Journal of Tianjin Normal University：Natural Science Edition
基金
国家自然科学基金资助项目(41973017)
天津市自然科学基金重点资助项目(19JCZDJC40700).
关键词
反硝化速率
厌氧氨氧化速率
沉积物
理化性质
海河
denitrification rate
anammox rate
sediment
physico-chemical properties
Haihe River
