底泥覆盖对氮磷释放及休眠蓝藻复苏的影响  

Effects of sediment capping on the nutrients release and recruitment of dormant cyanobacteria

作　　者：杨诗幼 唐炳然 罗竣潇 梁嘉良 何强[1] 李宏[1] YANG Shi-you;TANG Bing-ran;LUO Jun-xiao;LIANG Jia-liang;HE Qiang;LI Hong(Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment,Ministry of Education,Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学,三峡库区生态环境教育部重点实验室,重庆400045

出　　处：《中国环境科学》2024年第11期6322-6331,共10页China Environmental Science

基　　金：国家自然科学基金资助项目(52370199);重庆市技术创新与应用发展专项重点项目(CSTB2023TIAD-KPX0092)。

摘　　要：构建了室内复苏实验体系,选用镧改性膨润土和粉煤灰基沸石为氮磷吸附材料,设置对照组、控氮组(粉煤灰基沸石覆盖)、控磷组(镧改性膨润土覆盖)、氮磷双控组(镧改性膨润土和粉煤灰基沸石混合覆盖),进行为期120d的培养实验,探究了材料覆盖沉积物后对沉积物-水剖面氮磷去除的效果与机制,进而分析了其对沉积物中休眠蓝藻复苏的影响.结果表明:实验结束时,对照组表层沉积物(0~2cm)间隙水中磷酸盐和氨氮分别为0.732和0.044mg/L.与对照相比,控磷组磷酸盐被削减97.81%;控氮组氨氮被削减65.91%.表明控磷组和控氮组仅分别抑制了沉积物-水剖面中的磷酸盐和氨氮的释放.氮磷双控组同时抑制了沉积物中氮磷的释放,实验结束时上覆水中总磷和总氮较初始分别降低33.33%和57.18%.此外,材料覆盖提升了沉积物表层中参与反硝化作用微生物(如Thiobacillus,Sulfuricurvum)和硝酸盐还原反应微生物(如norank_f_Anaerolineaceae)的相对丰度,这有利于沉积物中氮的去除.实验结束时,对照组的叶绿素a含量为24.36μg/L,为控氮组、控磷组和氮磷双控组的16.13倍、6.07倍和32.48倍;同时控氮组、氮磷双控组蓝藻门浮游植物相对丰度较对照组降低12.24%和10.16%;硅藻门的相对丰度与对照组相比明显升高,分别是对照组的2.34倍和2.33倍,表明浮游植物多样性有所提高.研究结果表明氮磷双控可更有效地抑制休眠蓝藻复苏.To explore the effect of nutrients removal on the recruitment of the dormant cyanobacteria in sediments as well as the mechanism involved,we conducted a microcosm experiment,in which lanthanum modified bentonite and fly ash-based zeolite were used as nitrogen and phosphorus adsorption materials.Specifically,a control group,nitrogen controlling group(capping the surface sediment with fly ash based zeolite),phosphorus controlling group(capping with lanthanum modified bentonite),and a nitrogen and phosphorus double controlling group(capping with fly ash based zeolite mixed with lanthanum modified bentonite)were set up.The results showed that the concentration of phosphorus and ammonia nitrogen in the pore water of the sediments in control group reached 0.732 and 0.044mg/L after 120 days incubation,while were reduced by 97.81%and 65.91%in the phosphorus controlling group and nitrogen controlling group,respectively.This indicated that these treatments inhibited the release of sedimental phosphate or ammonia nitrogen.In contrast,nitrogen and phosphorus double controlling can achieve efficient reduction in both nitrogen and phosphorus release,as the total phosphorus and total nitrogen concentration in the overlying water showed 33.33%and 57.18%reduction in comparison with their initial value.In addition,Capping the sediment increased the relative abundance of denitrification microorganisms(e.g.Thiobacillus,Sulfuricurvum)and nitrate reduction reaction microorganisms(e.g.norank_f_Anaerolineaceae)in the surface sediment.At the end of the experiment,the concentration of chlorophyll a in the control group was 24.36μg/L,which was 16.13,6.07 and 32.48 times of that in the nitrogen controlling group,phosphorus controlling group,and nitrogen and phosphorus double controlling group,respectively.The relative abundance of cyanophyta in the nitrogen,and nitrogen and phosphorus double controlling group were decreased by 12.24%and 10.16%,respectively.While the relative abundance of diatomata was higher than that in control group,with

关 键 词：镧改性膨润土 粉煤灰基沸石 蓝藻 复苏 氮 磷 

分 类 号：X524[环境科学与工程—环境工程]