摘要
在巢湖西北半湖近岸带设置大型围隔研究秋季连续打捞蓝藻对湖泊温室气体通量的影响,应用YL-1000型大型仿生式水面蓝藻清除设备进行原位打捞蓝藻,通过便携式温室气体分析仪静态箱法对大型围隔内水气界面CH 4、CO 2通量特征及其影响因素进行观测.结果表明:对比未打捞区,蓝藻连续打捞下打捞区水体中叶绿素a(Chl.a)、悬浮物(SS)浓度不断下降,两者削减率分别为72%、85%,Chl.a、SS浓度分别下降到29.6±2.5μg/L、12.5±1.2 mg/L,打捞对围隔内颗粒态物质去除效果十分明显;打捞过程中水体溶解性有机物(DOM)中微生物代谢类腐殖质(C1)、类蛋白(C3)显著下降趋势,打捞区C1、C3组分(0.18±0.02、0.06±0.01 RU)强度明显低于未打捞区(0.26±0.05、0.12±0.03 RU),打捞能有效控制藻源性溶解性有机质释放.同时,打捞区水气界面CH 4通量呈显著下降趋势,未打捞区CH 4通量平均值(17.473±1.514 nmol/(m 2·s))为打捞区(7.004±4.163 nmol/(m 2·s))近2倍,CH 4通量与Chl.a、C1、C3组分均呈显著正相关,水体中藻源性溶解态有机质对CH 4通量具有促进作用;打捞区CO 2释放通量呈显著上升趋势,打捞区CO 2吸收通量(-0.200±0.069μmol/(m 2·s))明显低于未打捞区(-0.344±0.017μmol/(m 2·s)),CO 2通量与Chl.a、温度均呈显著负相关.秋季打捞对CH 4、CO 2综合日平均通量减排量值为0.275±0.076 mol/(m 2·d)(以CO 2当量计).研究结果揭示了巢湖秋季连续打捞蓝藻过程对水气界面温室气体具有显著减排作用,且能在一定程度上减缓蓝藻水华与湖泊富营养化、气候变暖之间的恶性循环,为湖泊碳循环和蓝藻水华灾害防控提供科学数据支撑和理论参考.
To investigate greenhouse gas flux on the water-air interface in autumn,the large enclosures were built up in the near-shore zone of the northwestern Lake Chaohu,China.The YL-1000 large-scale bionic cyanobacteria removal equipment was used to salvage cyanobacteria in situ.The characteristics of CH 4 and CO 2 fluxes and their influencing factors in the salvaging and control zone were observed by static chamber method equipped with a portable greenhouse gas analyzer.The results showed that the concentration of chlorophyll-a and suspended solids(SS)(29.6±2.5μg/L and 12.5±1.2 mg/L,respectively)in the salvaging zone significantly decreased with the reduction rate of 72%and 85%,respectively,compared with those in the control.The removal of particulate matter like total nitrogen,total phosphorus,SS and COD Mn after salvaging was effective.The microbially-derived humic-like(C1)and autochthonous protein-like(C3)components in the DOM significantly decreased during the salvaging process.The C1 and C3 fluorescence intensity(0.18±0.02 RU and 0.06±0.01 RU,respectively)in the salvaging zone were significantly lower than those of control(0.26±0.05 RU and 0.12±0.03 RU,respectively),which suggested that salvaging can effectively control the release of algal-derived dissolved organic matter.The average flux of CH 4 in the control(17.473±1.514 nmol/(m 2·s))was twice than that of the salvaging zone(7.004±4.163 nmol/(m 2·s)).In the salvaging zone,CH 4 flux was significantly positively correlated with Chl.a,C1 and C3 components,which suggested that algal-derived organic matter could promote CH 4 flux.The CO 2 flux showed a significant upward trend in the salvaging zone and remained constant in the control.The CO 2 flux(-0.200±0.069μmol/(m 2·s))in the salvaging zone was significantly higher than that in the control(-0.344±0.017μmol/(m 2·s)).The CO 2 flux was significantly negatively correlated with Chl.a and temperature in salvaging zone.The total greenhouse gas emission reduction for CH 4 and CO 2 is 0.275±0.076 mol/(m 2·d)(carbon dioxide equivalent).The results reveal that the continuous cyanobacterial salvaging process in Lake Chaohu reduces the flux of greenhouse gas on the water-air interface,and can slow down the vicious cycles between cyanobacterial blooms and lake eutrophication and climate warming.
作者
荀凡
杜先
陈新芳
刘高飞
齐天赐
冯慕华
XUN Fan;DU Xian;CHEN Xinfang;LIU Gaofei;QI Tianci;FENG Muhua(State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,P.R.China;University of Chinese Academy of Sciences,Beijing 100049,P.R.China;College of Environmental Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009,P.R.China;College of Hydrology and Water Resources,Hohai University,Nanjing 210008,P.R.China)
出处
《湖泊科学》
EI
CAS
CSCD
北大核心
2020年第6期1707-1722,共16页
Journal of Lake Sciences
基金
国家水体污染控制与治理科技重大专项(2017ZX07603-005,2017ZX07203-003)
国家自然科学基金项目(41877482,41471075)
江苏省高校水处理技术与材料协同创新中心项目联合资助.
关键词
巢湖
温室气体通量
蓝藻水华
打捞
藻源有机物
Lake Chaohu
greenhouse gas flux
cyanobacterial bloom
harvest
algal-derived organic matter
作者简介
通信作者:冯慕华,E-mail:mhfeng@niglas.ac.cn.
