A Relative Research About Alage Multiplication Being Affected By TN/TP In Water

Eutrophication has already a global environmental problem and causes universal attention. With the high speed development of economy and society, eutrophication is more and more severity. Now, much lake and reservoir in China cause serious eutrophication that affect water function and hinder normal social economy develop. The dissertation carried out a relative research on algae multiplication being affected by TN/TP. The conclusion as follows:①It used tap water as experimental water .The tap water was placed and aeration a few days to dispose parts of surplus chlorine. Referring to relative covers and useing eutrophicate water simple from Dianchi which the TN was 7.59mg/L, TP was 0.28mg/L and COD was 162mg/L, it setted total nitrogen consistence to be 10mg/L. When TN/TP changed from 4:1 to 25:1, it setted six ratios: 4:1,10:1,12:1,15:1,20:1,25:1 to experiment. In experiment, when TN was 10mg/L and the ratio of TN and TP reached definite rang, there had took place eutrophication by using tap water as experimental water.②When TN/TP changed within the range of 10:1~12:1, the period of algae production and the days that algae consistence reached peak value reduced with TN/TP increased, but the peak value of algae consistence increased with TN/TP increased. When TN/TP changed within the range of 12:1~25:1, the period of algae production and the days that algae consistence reached peak value increased with TN/TP increased, but the peak value of algae consistence reduced with TN/TP increased. When TN/TP is 12:1, the multiplication of algae reaches the fastest speed, the period of algae production and the days of algae consistence reached peak value were shortest, the algae consistence was maximal. When TN/TP was 4:1, the multiplication of algae was most slow, the algae consistence was also thin and there was no peak consistence during observing time.③Season has great influences on the multiplication of algae. Usually in the period of summer (27℃~ 35℃) the algae production was short and last out 20~44 days approximately. The peak value of algae consistence appeared fastly and last out 7~12 days approximately. The peak value of algae consistence was maximal. In the period of winter (8℃~ 14℃) the algae production was long and last out 38~68 days approximately. The peak value of algae consistence appeared slowly and last out 10~15 days approximately. The peak value of algae consistence was thin. The results showed summer was more suitable than winter for multiplication of algae.④After algae multiplicated, there exist various typical algae indicated eutroplication, for example, Microcystisaeruginosa and Merismopedia glauca (Ehr.) Nag. of Cyanophyceae; Selenastrum gracile Reinsch., Scenedesmus obliguus (Turp.) Kiitz and Volvox auyens Ehr. of Chlorophyta.The study is a part of the important project(CSTC 2006AB7020) of Chongqing scientific committee that was took charge by professor LUO Gu-yuan from College of Urban Construction and Environment Engineering, Chongqing University. The project is the test investigate of pollution evolutive reaction and control of Three Gorge sub river estuary and backwater area. This research provides some theoretic supports for defending and managing eutrophication.