化感物质用于景观水体应急控藻的试验研究

Experimental Study on Cinnamic Acid for Emergency Algae Control in Landscape Water Body

该文以肉桂酸(CA)作为化感物质,探究了CA对景观水体中藻类控制的整体效果、对景观水生态系统脱氮除磷功能的影响和对优势藻类斜生栅藻的抑制机理。室内单因素控制实验结果表明,100 mg/L和150 mg/L CA能显著抑制景观水体中藻类的生长(P<0.01),相比对照组,叶绿素a含量(Chl-a)分别下降75.24%和96.19%,且CA均在12 d内被完全分解;<100 mg/L的CA浓度组对景观水体中硝化细菌和聚磷菌等微生物的影响均不显著(P<0.01)。选择优势生长藻斜生栅藻作为受试对象暴露于CA中培养9 d,结果表明CA对斜生栅藻的生长抑制作用显著(P<0.01),150 mg/L CA对Chl-a的去除率达到99.96%。扫描电镜显示150 mg/L试验组中藻细胞大量裂解,这可能与藻细胞膜脂质过氧化导致细胞膜通透性发生改变有关,相近CA浓度暴露下受试对象丙二醛浓度增大近3倍证实了这一推测。

The presented work aimed at investigating the overall effect of cinnamic acid(CA)as an allelochemical on controlling algae in landscape water and its impact on the nitrogen and phosphorus removal of the landscape water ecosystem,then further revealing the inhibition mechanism of dominant algae Scenedesmus obliquus.The results of indoor single-factor control experiments indicated that the cinnamic acid concentration of 100 mg/L and 150 mg/L could significantly inhibit the growth of algae in the landscape water(P<0.01)and the content of chlorophyll a(Chl-a)in the treated group decreased by75.24%and 96.19%,respectively,comparing with that of the controlled group.The concentration of cinnamic acid less than 100 mg/L had little effect on nitrifying bacteria and phosphorus-accumulating bacteria(P<0.01).Then the representative of the dominant algae Scenedesmus obliquus was selected as the test subject and exposed to cinnamic acid with different concentrations for 9 days.The results shows that cinnamic acid could inhibit the growth of Scenedesmus obliquus significantly(P<0.01)and the removal rate of Chl-a reached 99.96%when the concentration of cinnamic acid was 150 mg/L.In addition,the scanning electron microscope(SEM)photographs indicated that a large number of algal cells were lysed in the tested group of 150 mg/L which may be related to the changes in permeability of cell membrane caused by membrane lipid peroxidation of algae cells.The concentration of malondialdehyde(MDA)in the nearly tested group increased about 3 times higher than that of the controlled group confirmed this hypothesis.