Study On The Response And Adsorption Of Scenedesmus Obliquus To Antimony Stress

In this study,a static experiment was conducted to investigate the changes of biomass,chlorophyll a,antioxidant enzyme activity(MDA,SOD,CAT)and microstructure of algae cells under stress of 100,200,400,800μmol·L~-11 Sb(Ⅲ)and Sb(Ⅴ).The results showed that the growth of Scenedesmus oblique was promoted under the stress of low concentration of Sb(Ⅲ)and Sb(Ⅴ)for a short time,but with the time of stress,the increase of concentration inhibited the growth of the algae.Because of the stronger inhibitory effect of Sb(Ⅲ),the inhibition was also observed by scanning electron microscopy(SEM).A series of physiological and biochemical indexes were also changed under the process of Sb(Ⅲ)and Sb(Ⅴ)stress.The MDA which the products phenomenon of membrane lipidization and the content increased with the increase of stress time,and more serious.The activity of antioxidant enzymes such as SOD and CAT increased first and then decreased with the stress time,which indicated that the antioxidant enzymes had detoxification effect.The effects of biomass,pH and temperature on adsorption efficiency of Sb(Ⅲ)and Sb(Ⅴ)show that:the adsorption efficiency of Sb(Ⅲ)and Sb(Ⅴ)rise with the increase of biomass in a certain range,after reaching a certain value,the optimum biomass of the adsorption process is 3.0g and 2.0g,respectively.Under the same pH、temperature and biomass situation,the adsorption efficiency of Sb(Ⅲ)and Sb(Ⅴ)increased with the increase of time,and reached the adsorption equilibrium at 75min and100min,respectively.And the best adsorption efficiency pH situation for Sb(Ⅲ)and Sb(Ⅴ)is 4 and 2 respectively.The adsorption process is an endothermic process of Sb(Ⅲ)and Sb(Ⅴ)and can be promoted at higher ambient temperature,and increases with the increase of ambient temperature.The study about adsorption process of the inactivated Scenedesmus oblique on Sb(Ⅲ)and Sb(Ⅴ)found that 2hours before is a rapid adsorption process,which could be fitted by the adsorption kinetic equation,and the correlation coefficient was greater than 0.9.The adsorption process of Sb(Ⅲ)and Sb(Ⅴ)can be described by Freundlichl and langmuir isotherm equation,but Freundlich is more consistent with the adsorption process,the main reason is that the chemisorption is the main reason.At the same time,the thermodynamic model was used to study the Enthalpy change?H and Entropy change?S in the adsorption process.The Gibbs energy?G in the adsorption process decreased with the increase of temperature,and the adsorption efficiency increased with the increase of the adsorption environment temperature under the same conditions and shows that this is an endothermic reaction.During the adsorption of Sb,some functional groups such as carboxyl groups,hydroxyl groups and amino groups on the cell wall of alage,played a great role in the adsorption process.