溴氯海因在水环境中的降解及其对4种水生生物的急性毒性

研究了新型消毒剂溴氯海因(BCDMH)在水环境中的降解规律及其影响因素以及BCDMH对4种不同生态位水生生物(发光菌、小球藻、大型溞和斑马鱼)的急性毒性.结果表明:1)BCDMH的正辛醇/水分配系数(Kow)为3.74(25℃),在水环境中的降解符合一级动力学方程C=C0×e-k·t,其一级反应速率常数k随温度升高而增大,25℃时k值为0.3577,半衰期为1.72d.2)pH6～9时,pH值越低BCDMH降解越快,碱性条件对其降解有显著抑制;自然光照和曝气有利于BCDMH的降解.3)BCDMH对斑马鱼的96hLC50=3.68mg·L-1,属高毒;对大型溞的24hLC50=1.44mg·L-1,属高毒;对小球藻的96hEC50=4.15mg·L-1,属高毒;对发光菌的1hEC50=0.62mg·L-1,属极高毒.

Study on the Degradation Rule of Bromo - Chloro - Dimethyl Hydantoin (BCDMH)and Its Acute Toxicity to Four Aquatic Organisms

The paper studied the degradation rule of Bromo-Chloro-Dimethyl Hydantoin(BCDMH) in water environment and its acute toxicity to 4 aquatic organisms(Photobacterium phosphoreum, Chlorella vulgaris, Daphnia magna Straus and Brachydanio rerio).Results showed that:1) The n-octanol/water partition coefficient(Kow) of BCDMH was 3.74(25℃).First-order dynamics model could be used to describe the degradation of BCDMH.The equation was C=C0×e-k·t, and the constant k increased with the increase of temperature.The value of k was 0.3577, and the biological half-life of BCDMH was 1.72d when the temperature was 25℃ .2) In the range of pH 6 ～9, the lower the pH was, the higher the degradation rate would be, which meant that higher pH would inhibit the degradation of BCDMH.Natural lighting and aeration could accelerate the degradation of BCDMH.3) The 96h LC50 of BCDMH to Brachydanio rerio was 3.68mg·L-1(high toxicity);the 24h LC50 of BCDMH to Daphnia magna Straus was 1.44mg·L-1(high toxicity);the 96h EC50 of BCDMH to Chlorella vulgaris was 4.15mg·L-1(high toxicity);The 1h EC50 of BCDMH to Photobacterium phosphoreum was 0.62mg·L-1(extremely high toxicity).