Studies On The Toxicity Of Clomazone In Water And Its Hydrolysis

Regard the Lemna minor L and Rana limnocharis as the target,researched the toxicity of the Clomazone,and studied the hydrolysis dynamics of Clomazone and its factor.The main results summarized as following:Regard the Lemna minor L as the target,studied the influence of the Clomazo--ne to its growth and its pigment.The result indicat that the toxicity of the Clomaz--one to Lemna minor L's 24h IC₅₀ is 8.86 mg/L, 48h IC₅₀50 is 5.21 mg/L, 72h IC₅₀ is 1.92mg/L, 96h IC₅₀ is 1.66 mg/L.The influence of Clomazone to the pigment in Lemna minor L accords with the dosage-effect connection.With the dosage 's incr--ease,the chlorophyll and the carotene in Lemna minor L reduce obviously,and the value of chlorophyll a/b reduces too.Joint-toxicity of Clomazone and Cadmium on Rana limnocharis was studied in the present investigation. It was demonstrated that LC₅₀ of Clomazoneon Rana limnocharis were 15.62mg/L, 14.27 mg/L, 13.35 mg/L, 13.30 mg/L,While that of Cadmium were 5.63mg/L, 3.54 mg/L, 2.61 mg/L, 2.06 mg/L,respectively. Accord--ing to the addictive index method of Marking,It has been found that the addictive index(AI)were 0.25, 0.21, 0.19 and 0.14 in 24 h, 48 h 72h and 96 h respectively. revealing that there is a clear synergism action. And with the temperature's incre--ase, the toxicity of Clomazone on Rana limnocharis was weakened,While that of Cadmium on Rana limnocharis was strengthened,and the Joint-toxicity of the two is still a synergism action.The hydrolysis dynamics of Clomazone was studied at different temperatures, pH values and in three kinds of natural water. The results indicated that different pH Values affect the hydrolysis of Clomazone,While the hydrolysis rate accelerated with the rise of the temperature.Moreover,the hydrolysis of Clomzone in naturalwater was a little slower.