Research on the motivation trend of typical trace elements on algae bloom

The effect of micro-nutrients (Fe, Mn, Zn) on the proliferation of planktonic algae colony is one of the most important contents in the researches of cause analysis of algae blooms. Experiments on the impacts of typical micro-nutrients (P, Fe, Mn, Zn) on common algal blooms organisms (cyanobacteria, chlorophyta) were carried out by series of orthogonal experiments. The results show that these nutrients have significant impact on algae growth and stimulated cell-specific growth rates with ZincPhosphorusIronManganese. AGP (algae growth potential) experiments by separate addition of iron, manganese and zinc were further performed through single-factor experiments. The data obtained show that maximum algae growth rate appeared when concentration of Fe,Mn,Zn were 0.20mg/L, 0.13mg/L, 0.033mg/L,respectively. Furthermore, a positive motivation to the growth rate and biomass of algae was emerged with the concentrations of Fe, Mn and Zn range from 0.01~0.20, 0.01~0.13, 0.001~0.033mg/L, while there is a negative motivation with the increase of the concentrations of Fe, Mn and Zn above 0.20, 0.13, 0.033mg/L, respectively. By fitting the numerical relationships between concentrations of Fe, Mn, Zn and algal cell-specific growth rate, regression equations with correlation coefficient of 0.93, 0.87, 0.90 were obtained respectively. The results make it be able to predict the time and severity of outbreak of algae blooming to a certain precision extent according to the correlation between trace elements and algae growth rate or biomass. Experiment consequence also suggested that the significant levels of Manganese to algae had been severely weakened by the inhibitory effect among multi-microelements during orthogonal experiments. These results reveal that the mechanism of Manganese is rather complicated that further researches are needed to be performed.