Influence of nitrogen and phosphorus concentrations on the growth characteristics of Microcystis aeruginosa

Microystis aeruginosa was cultured in solutions of different initial nitrogen and phosphorus concentrations.The semi-saturation constants(Ks) of Microystis aeruginosa to P and N were calculated respectively by using the Monod equation.The results show that the Microystis aeruginosa grew normally when the concentrations of N and P were greater than 4.0 mg·L~(-1) and 0.50 mg·L~(-1) respectively.The optimum concentration ranges of N and P for Microystis aeruginosa growth were 32.0～64.0 mg·L~(-1) and 1.0～1.50 mg·L~(-1) respectively.Ks_N is higher than K_s_p,which indicates that the affinity of P to Microystis aeruginosa is higher than N. When the concentration ranges of N and P were 0.20～64.0 mg·L~(-1) and 0.02～1.50 mg·L~(-1) respectively,they had high liner correlation with the largest extent quantity of Microystis aeruginosa. The special growth rate increases continuously when the concentration ranges of N and P are 0.20～Y1.60 mg·L~(-1) and 0.02～0.50 mg·L~(-1) respectively.