Studies On The Toxicities Of Quinclorac To Duckweed And Xiangyunji And Its Photodegradation In Aqueous Solution

In this dissertation, the acute toxicities of 25%EC quinclorac to duckweed and xiangyunji were detected. The effects of quinclorac on the content of chlorophyll a in duckweed, and the activities of Na+-K+-ATPase, Mg"+-ATPase in xiangyunji gill and liver were studied, meanwhile the possible inhibition mechanisms of ATPase by quinclorac were discussed. Based on these results, the thesis also studied quinclorac photodegraded, under the illumination of high press mercury lamp, in different pH values, added H2O2 and acetone aqueous solutions, as well as in different types of water. The mainly results were summarized as followsUnder the condition of illumination cultivation, the 96 hours of IC.so of 25%EC quinclorac to duckweed was 20.6mg/L. At the water temperature of 23 + 1癈, the 96 hours of LCfo of 25%EC quinclorac to xiangyunji was 149.1mg/L, Revealed that the toxicity of 25%EC quinclorac is low to duckweed and xiangyunji.The effects of quinclorac on chlorophyll a content in duckweed strengthed as the concentration of quinclorac increased. The influence was slight at the concentration 1 Omg/L, and evident at 12.6mg/L.The activities of Na+-K"-ATPase and Mg2^-ATPase in xiangyunji gill and liver decreased obviously with treated concentrations increased and time lengthened, showed a striking dose-time-response relationship. In the treatments that are treated with the same time but different concentrations, when the concentration was 18.6mg/L, the effects of quinclorac on Na+-KT-ATPase in gill was notable, and the effects of quinclorac on Mg2+-ATPase in gill, Na+-K7-ATPase as well as Mg2+-ATPase in liver was very remarkable. In the treatments treated with the same concentration but different time, when treated with 74.6mg/L and 8 hours, the effects of quinclorac on Na+-K7-ATPase in gill and liver were very remarkable, and on Mg~~-ATPase were notable.Under the illumination of high pressure mercury lamp, quinclorac photodegrades following a pseudo-first-order kinetics in aqueous solution, the pH of the reaction buffers was shown much effect on the photolysis of quinclorac, when 5 well water >pure water> pond water > paddy water.