Effects Of Pb²⁺,Zn²⁺ On The Growth Of Phaeocystis Globosa Scherffel And Prorocentrum Donghaiense And Interaction

Sea area is complicated when red tide happens. It is contain many kinds of contaminant, such as heavy metal, organic matter. In order to know the growth course of red tide algal in polluted sea area and the migration of the heavy metal when red tide happens, we can't ignore those factors. In this paper, we study the effects of Pb²⁺, Zn²⁺ on the growth of Phaeocystis globosa Scherffe and Prorocentrum donghaiense and the biosorption.The experiment results showed that lower doses of Pb²⁺,Zn²⁺ promoted the growth of red tide algae, but higher dose inhibited the growth. A growth model, with consideration of effect of Pb²⁺,Zn²⁺ on the growth of red tide algae, was developed by incorporation Logistic growth model with Lorentz equation and GaussAmp equation.Lorentz equation can describe the effect of Pb²⁺,Zn²⁺ on the growth rate constant while GaussAmp equation can describe the effect of Pb²⁺,Zn²⁺ on the final biomass of algae. It was demonstrated that the growth model showed good fitting for the experimental data and the related coefficients was 0.875-0.998, with an average of about 0.941.The experiment of biosorption of Prorocentrum donghaiense and Phaeocystis globosa Scherffe for Pb²⁺,Zn²⁺ showed that two kinds of red tide algae can adopt more Pb²⁺ than Zn²⁺. The maximum adsorption of Prorocentrum donghaiense for Pb²⁺,Zn²⁺ is 2.7,10.1mg/g, respectively. The maximum adsorption of Phaeocystis globosa Scherffe for Pb²⁺,Zn²⁺ is 18.6,9.1 mg/g, respectively. The process of biosorption can divided into two stages, the first stage was physical sorption and reached equilibrium very quickly (15 minutes); and the second stage was slowly, with little change of. The pH had significant effects on biosorption; the adsorbance of algae is low at a low pH and larger when pH was above 5. The biosorption kinetics could be described by the pseudo second order equation quite well (R₂=0.999). The equilibrium isotherm could be fitted by the Langmuir model.