水绵(Spirogyra)的除磷特性及其对微藻生长的抑制作用

针对富营养化水体的除磷和微型藻类生物生长的抑制问题,研究了水绵(Spirogyra)的除磷特性及其对微藻生长的抑制作用.以蓝藻中的Microcystis aeruginosa、绿藻中的Scenedesmus为代表,研究了Spirogyra对微型藻类生物生长的抑制特性.共培养实验结果表明,Spirogyra对以上2种藻类的生长具有明显的抑制作用,对Chlorella的生长也有同样的抑制作用;共培养、Spirogyra培养液及其过滤液对Microcystis aeruginosa、Scenedesmus生长的影响等实验表明,这种抑制作用是因Spirogyra生长的代谢分泌物或其共生微生物而引起.用总磷(TP)浓度小于1.60mg·L-1的模拟湖水进行实验,发现Spirogyra在生长过程中可以有效地去除水中的磷.磷的去除效率与氮营养物成份有关,NH4 -N/NO3--N质量比为3:7时除磷效率最高.除磷过程中无机氮磷比的变化规律表明,除却Spirogyra同化除磷之外,Spirogyra生长会引起水体pH升高,从而诱导磷沉积是除磷的重要机制之一.Spirogyra对微型藻类生长良好的抑制性能以及除磷特性为富营养化水体的生物修复、水源水的保护提供了新的技术途径.

Characteristics of phosphorus removal and growth inhibition of micro-algal species by Spirogyra

Phosphorus removal and the inhibition of micro-algal species growth in the presence of Spirogyra were investigated,aiming at phosphorus removal and the inhibition of micro-algal species growth in eutrophicated water bodies.Inhibition of micro-algal species by Spirogyra was studied with Microcystis aeruginosa,a representative of blue algae,and Scenedesmus as a representative of green algal species.Co-cultivation experiments showed that Spirogyra inhibited the growth of the two algal species and Chlorella species strongly.The poor growth of Microcystis aeruginosa and Scenedesmus may result from the metabolic secretions of Spirogyra or microorganisms accreted with Spirogyra by a series tests,such as Spirogyra co-cultivating with Microcystis aeruginosa and Scenedesmus,culture liquid and filtered culture liquid of Spirogyra affacting growth of Microcystis aeruginosa and Scenedesmus.The experiments were conducted on simulated lake water with a phosphorus concentration of less than 1.6 mg·L^-1,and phosphorus was removed efficiently during the growth of Spirogyra.The composition of nitrogen nutrients affected the phosphorus removal efficiency,reaching a maximum when the ratio of NH₄⁺-N to NO₃^--N was 3:7.The changing ratio of inorganic nitrogen to phosphorus during Spirogyra growth showed that phosphorus precipitation,which was induced by an increase of pH,was also an important mechanism for phosphorus removal in addition to assimilation by Spirogyra.The cultivation of Spirogyra,which inhibits micro-algal species growth and removes phosphorus,provides a new method to bioremediate eutrophicated water bodies and to protect raw water resources.