不同氮源和曝气方式对淡水藻类生长的影响

利用水族箱微宇宙研究了2种氮源水体中不同曝气条件对藻类生长的影响.试验使用铵态氮(NH₄⁺-N)和硝态氮(NO₃^--N)作为氮源,每种氮源水体分别设置不曝气、连续曝气、昼间曝气和夜间曝气4个处理.结果显示:试验初期以NH₄⁺-N为主要氮源的水体中藻类生长明显好于以NO₃^--N为主要氮源的水体.试验后期则以NO₃^--N为主要氮源的藻类生长情况更好.连续曝气对于2种氮源水体中藻类生长有着不同的影响;昼间曝气对2种氮源的藻类生长影响不大;而夜间曝气对藻类生长有明显的抑制作用.NH₄⁺-N含量较高的水体中蓝藻容易成为优势种,而NO₃^--N含量高的水体中则以绿藻为主.不同曝气条件下藻类优势种没有明显差别.

Effects of Nitrogen Source and Aeration Mode on Algae Growth in Freshwater

Aquarium microcosms were used to study the effects of nitrogen source and aeration mode on the growth and species changes of algae in freshwater.Nitrate nitrogen(NO₃^--N) and ammonia nitrogen(NH₄⁺-N) were used as nitrogen sources.For each nitrogen source,four modes of aeration were selected, including control,continuous aeration,aeration during the day,and aeration at night.In the early stage of the experiment,algae in the NH₄⁺-N treatment experiment grew well.In the later stage,algae in the NO₃^--N treatment experiment grew better.For different aeration modes,continuous aeration show varied effects on algae growth in the two nitrogen source treatments.Day-only aeration had little effect on algae growth.Night-only aeration inhibited algae growth considerably.In NH₄⁺-N treatments,cyanophyta became dominant species easily.In contrast,chlorophyta dominated in NO₃^--N treatments.