Monitoring Pesticide Pollution By Blue-alga

Regarding Microcystis aeruginosa, Microcystis flos-aquae and Anabaena flos-aguae as monitoring organisms, the thesis compares dry weight and chlorophyll a concentration with absorbance at 680nm of three blue algae and screens the right pesticide adjuvants used in alga monitoring pesticides pollution, and finally compares the sensitivity of three blue algae to 34 pesticides and studies the lowest observed effective concentration ( LOEC) no observed effective concentration (NOEC ) and max acceptable toxicity concentration (MATC) , the results are obtained as follows:1. Comparing absorbance at 680nm with dry weight and chlorophyll a concentration , there are significant correlation between them, and their correlation coefficient (r) are all above 0.98, it indicates the absorbance of alga is a good index which reflects the alga biomass.2. To three blue algae tested, acetone is the first selected adjuvant in making up right concentration pesticides through assaying the growth effects of 10 adjuvants to three blue algae tested. However, some pesticides do not dissolve in acetone when their dosage is larger or separate out after added alga culture solution. Then we select other pesticide adjuvants according to the order of adjuvant toxicity to alga and control their dosage under NOEC.3. The thesis researches the growth effects of 34 pesticides to three blue algae by testing the absorbance of alga culture. The result shows that these pesticides have different degree of effect to three blue algae tested and 96hrEC5oranges from 0.0002mg/L to 12634.53mg/L.4. The thesis compares the sensitivities of three algae tested to the 34 pesticides, the result indicates monitoring the amino formic acid ester pesticides pollution by Microcystis aeruginosa is better than Microcystis flos-aquae and Anabaena flos-aguae. The effect is better by assaying the photosynthesis inhibition herbicides and fungicides such as benalaxyl, chlorothalonil, cymoxanil and propiconazol organophosphorus pesticides than Microcystis aeruginosa and Anabaena flos-aguae. There is high sensitivity of three blue algae to organotin pesticides, therefore, using three blue algae can monitor the organotin pesticides pollution to the environment.5. The thesis also studies LOEC, NOEC and MATC of 34 pesticides to three blue algae so that the pesticides are used reasonably and safely in the environment.