Screening Of Lead Compound Of Algaecide For Microcystis And Analysis Of Toxic Effects

Alead compound of algaecide,named MS1,was obtained by screening a number of synthesized chemicals.MS1(≥1 mg·L^-1)decreased the cell density of Microcystis aeruginosa DS by 90%in 3d treatment.72h-EC₅₀of MS1 on Microcystis aeruginosa DS, 7806,and 7820 were all less than 0.25 mg·L^-1,while 72h-EC₅₀of MS1 on Anabaena flosaquae 7120,Euglena gracilis,Chlamydomonas reinhardtii,Navicula pelliculosa,and Scenedesmus obliquu were 12.76,32.3,3.13,10.17 and 22.4 mg·L^-1respectively.The results showed those algal species were less sensitive than Microcystis aeruginosa to MS1.The acute toxicity test of Oryzias latipes and Daphnia Magna to MS1 showed that the 72h-LC₅₀were 1.04 mg·L^-1and 1.33mg·L^-1respectively.The data above indicates MS1 high and specific algaecidal effect on Microcystis but also toxic to fish and zooplankton.As a lead compound of algaecide,it can be modified by changing side groups of the chemical structure to reduce its toxicity to non-target organisms and increase its degradability in the environment.MS1 derivative algaecides can be applied to urban water bodies and industrial water treatment.In order to study the toxic effects of MSl on the M.aeruginosa DS,the algae was exposed to MS1 to measure the content of photosynthetic pigment,MDA,and protein. Results showed that,MSl had inhibition effect on growth of M.aeruginosa DS compared with the control.With the increase of concentrations,the inhibition increased correspondingly.MDA contents increased significantly(compared with the control, p＜0.01),only when concentration of MS1 was in a low level.Protein contents decreased significantly(p＜0.05),when concentration of MS1 was higher than 1 mg'L^-1.It indicated the main mechanism of MS1 inhibition in M.aeruginosa was inhibition the synthesis of protein and chlorophyll.