高营养盐水平下葡萄糖添加对微囊藻水华的控制

Glucose enrichment to control Microcystis( cyanobacteria) bloom under high nutrient level

为了控制蓝藻门微囊藻属水华,在玻璃温室中进行了一个添加葡萄糖控制蓝藻门微囊藻属水华的试验。试验初始水体为发生严重蓝藻门微囊藻属水华的水体,叶绿素a浓度高达422.78μg·L^(-1)。试验共分为1个对照和1个处理,对照中不添加葡萄糖,处理中添加葡萄糖。葡萄糖的添加浓度依据水体总氮浓度而定,按DOC∶TN≈20∶1进行添加。试验过程中每个玻璃瓶均曝气。结果表明,处理的叶绿素a含量(Chl-a)、上午及下午的DO、p H值均明显低于对照(P<0.05),处理的DOC、TSS和OSS浓度均高于对照(P<0.05),处理和对照的TN、TP、DTN、DTP、SRP浓度均没有显著差异(P>0.05)。试验后期,对照和处理的微囊藻大群体均变小了,且处理中微囊藻群体比对照解散、解体得更明显,尤其是处理中微囊藻形成了小群体甚至是双细胞或者单细胞形态。结果表明,添加葡萄糖能够控制高营养水体中微囊藻水华,其机理是葡萄糖添加促进了水体异养细菌的生长,而与微囊藻形成竞争。

In order to control cyanobacterial Microcystis bloom,an experiment with glucose enrichment was carried out under high nutrient level with 5 L glass bottles in greenhouse.There was a control of no glucose enrichment(Control)and a treatment with glucose enrichment(+Glu),each with 3 replicates.The initial water for the experiment was severely Microcystis bloomed,in which the chlorophyll-a(Chl-a)concentration was 422.78μg·L-1.The glucose enrichment was according to the total nitrogen concentration,and with the dissolved organic carbon to total nitrogen ratio(DOC∶TN)≈20∶1.During the experiment,every bottle was aerated with an air stone.The results showed that,the Chl-a,dissolved oxygen and pH values both at 09∶00 A.M.and 14∶00 P.M.in the treatment were all significantly lower than those in the control(P<0.05),and the DOC,total suspended solids(TSS)and organic suspended solids(OSS)concentrations in the treatment were all significantly higher than the control(P<0.05).And there was no significant difference in the total nitrogen(TN),total phosphorus(TP),dissolved total nitrogen(DTN),dissolved total phosphorus(DTP)and soluble reactive phosphorus(SRP)contents between the control and the treatment(P>0.05).Then the discovery for the phytoplankton under microscope showed,with the elongation of the experiment,the Microcystis colonies became smaller with fewer cells both in the control and the treatment,and the Microcystis colonies in the treatment became much smaller,even with morphology in two cells or unicell.The results indicated that,glucose enrichment can control Microcystis bloom,and the mechanism was that organic carbon improved the growth of heterotrophic microorganism,which competed nutrients with Microcystis.