Research On Algae Inhibition Characteristics Of Natural Materials On Microcystis Aeruginosa

In this thesis,the inhibitory properties of natural plant allelopathic effects on Microcystis aeruginosa are studied.By screening effective algae inhibiting materials,the treatment methods of algae inhibiting materials are compared and the effective algae concentration of the materials is determined.Based on the results and realistic application possibilities select three basic components for orthogonal experiment,determine the optimal composition and composition ratio of the algaecide,and conduct preliminary research on the stability of algaecide and the mechanism of algae inhibition.The research is used to provides theoretical reference and experimental basis.The main research results are as follows:(1)Extract rhizome from Garlic,Rhubarb,Spatholobus,Licorice,and Yam;peel or bark from Orange,Grapefruit,Pomegranate,Poplar,Eucommia bark;leaves from tea,wormwood,lotus,ginkgo,reed for algae inhibition experiments.The results show that allelochemicals ware present in various organs of the plant.(2)The results of screening experiments show that garlic,licorice,yam,orange peel,grapefruit peel,tea and reed leaf all show significant algae-inhibiting effects,and the yam>licorice>grapefruit peel>cucurbit eucalyptus>garlic>oranges peel.The inhibition rate of various materials against Microcystis aeruginosa increases with time during the experiment.(3)The algal inhibiting effect based on different treatments on same effective algal inhibiting material shows that:different treatments had little influence on the algae inhibition effect of garlic and reed leaves;it had certain influence on the algae inhibition effect of orange peel and grapefruit peel,the algae inhibition effect of the leach liquor group and the fermentation broth group is slightly higher than that of the dry powder group);the effects on licorice,yam and tea were greater,and the inhibition effects of the dry powder group and the fermentation broth group were significantly higher than those of the leach liquor group.(4)The experiment on the optimum concentration of the effective algal inhibiting material fermentation broth shows that:when the concentration of garlic fermentation broth is higher than 5g/L and the concentration of licorice and yam fermentation broth is higher than 2.5g/L,the broth can effectively inhibit the growth of Microcystis aeruginosa;orange peel and grapefruit peel,tea leaves and reed leaves showed the phenomenon of "low promotion and high inhibition".When the concentration of orange peel and grapefruit peel fermentation broth is less than 0.25g/L,and the concentration of tea and reed leaves fermentation broth is less than 0.188g/L,the broth will promote the growth of Microcystis aeruginosa.While the concentration of orange peel,grapefruit peel,tea leaves,and reed leaves fermentation broth are higher than 1g/L,2g/L,3g/L,1.5g/L,respectively,the broth will effectively inhibit the growth of Microcystis aeruginosa.(5)Garlic,orange peel and reed leaf fermentation broth are used as the basic components of the orthogonal experiment of algaecide inhibitor.By comparing the reduction of Chlorophyll A content in algae within seven days,the best component of algaecide is:the dosage of garlic is lOg/L,the dosage of orange peel is 2g/L,and the dosage of reed leaves is 4.5g/L.The reed leaves play a major role in inhibiting the growth of Microcystis aeruginosa.(6)The stability study of the optimal algaecide agent obtained by orthogonal experiment shows that the algaecide inhibitor still shows significant algae inhibition effect after high temperature sterilization,there is no significant difference between the sterilization group and the non-sterilization group(P>0.05).The inhibitory effect of algaecide at 4? and normal temperature storage conditions show a good inhibitory effect.Under the storage condition of-20?,the inhibitory effect of algaecide on the growth of Microcystis aeruginosa is significantly lower;when the initial concentration of algae is 140.2?g/L,280.4?g/L and 560.8?g/mL,algaecide inhibits the growth of Microcystis aeruginosa.When the initial concentration of algae is 1121.6?g/L,the algae-inhibiting effect of algaecide is relatively reduced.(7)The mechanism study of allelopathic effects shows that under the allelopathic effect,the chlorophyll A content of algae shows a significant downward trend,and the inhibition rate of Microcystis growth shows an upward trend;the content of soluble protein decreased rapidly with time;the content of MDA increased first and then decreased;the activity of SOD,POD and CAT increased first and then decreased rapidly.