Study On The Impact Of Main Nutrients And Strength Of Illumination,Temperature On Growth,Over-winter And Recovery Of Microcystis Aeruginosa

In order to prevent and control eutrophication and algae bloom,this papers studied the impact of strength of illumination,temperature,TN,TP,TN/TP and trace element Fe³⁺on the growth,over-winter and recovery of Microcystis aeruginosa.The experiments showed that:(1)N,P had very impact on Microcystis aeruginosa's growth,and Phosphorus is more effective to algae's growth than nitrogen.When N,P was insufficient,it limited Microcystis aeruginosa's growth,it achieved the stabilization period ahead of time; otherwise,the algae maintained longer in the vegetal period.This indicated that in the consideration nitrogen phosphorus influence algae cell growth,not only N,P concentration but also TN/TP must simultaneously be payed attention to.When N,P were sufficient,the strength of illumination was very tremendous influence to Microcystis aeruginosa's growth.The situation dovetailed nicely with reality.(2)The AGP experiment indicated that TN/TP scope which was suitable for the growth of Microcystis aeruginosa was wider,in 5:1-21.4:1,and obviously in 10:1.0-14.6:1.In the same TN/TP,the lower phosphorus concentration limited the growth of Microcystis aeruginosa.(3)Compared with Microcystis aeruginosa's growth in 8℃,15℃,20℃.The results showed that the temperature influenced significantly to Microcystis aeruginosa's growth.In 15-20℃range,the growth rate elevated along with the temperature enhanced,but when 8℃,Microcystis aeruginosa's growth reproduction sign was weak.(4)When the Fe³⁺concentration in the water was lower than 50μg/L, Microcystis aeruginosa's growth was suppressed,the growth rate was quite slow; When the Fe³⁺concentration was higher than 50μg/L,Microcystis aeruginosa's growth was obvious,but when the Fe³⁺concentration was higher than 1000μg/L, although Microcystis aeruginosa's growth was obvious,but the stabilization period reduced,Microcystis aeruginosa's growth entered the decline phase very quickly. (5)Studied the impact of different nutritive elements composition on Microcystis aeruginosa's over-winter growth,the results showed that when the nutritive elements were sufficient,the winter temperature influenced significantly to the growth of Microcystis aeruginosa which was in logarithm vegetal period.When the temperature dropped under 14℃,algae cells quantity declined rapidly along with the reduce of temperature;but Microcystis aeruginosa in the stabilization period wasn't influenced obviously when the winter temperature fell suddenly.(6)Studied the impact of different nutritive elements composition on Microcystis aeruginosa's recovery growth.The results showed that when the nutritive elements were sufficient,the growth tendency of Microcystis aeruginosa which was in dormant period was different as a result of different nutritive elements concentration.