二氧化氯对摇蚊幼虫的毒效试验及影响因素

以水厂原水为试验水样,研究了二氧化氯对摇蚊不同龄期幼虫的毒性效果（24 h）,并考察了温度和接触时间对二氧化氯毒性效果的影响.结果表明,二氧化氯对摇蚊幼虫具有极为显著的毒性作用,25℃时二氧化氯对4龄幼虫的24h半致死浓度（LC₅₀）为0 .41 mg/L.二氧化氯对摇蚊幼虫的毒力随幼虫龄期的增长而降低,1龄幼虫对二氧化氯最敏感,其中二氧化氯对4龄幼虫的LC₅₀是1龄幼虫的1 .78倍.二氧化氯的毒力在一定范围内符合正温度系数规律,二氧化氯对4龄幼虫的毒力在15～30℃范围内增加了2 .16倍.接触时间从12 h延长至24 h,二氧化氯对4龄幼虫的毒力增幅显著;当接触时间至36 h,与接触24 h相比毒力增幅不明显.

Toxicity and Influencing Factors of Chlorine Dioxide to Chironomid Larvae

The toxic effect of chlorine dioxide to the different instar larvae of chironomid was studied using raw water as test sample. Furthermore, the effect of temperature and contact time on toxicity of chlorine dioxide was observed. It was found that chlorine dioxide possessed significantly toxic effect, and the LC50 value of chlorine dioxide to the 4th instar larvae was 0.41 mg/L(24 h). The toxicity of chlorine dioxide declined with the development of instar larvae. The 1st instar larvae was most sensitive to chlorine dioxide among the four instars, and the LC50 value of chlorine dioxide to the 4th instar was 1.78 times of that of the 1st instar larvae. Temperature was proved to have significant positive effect on chlorine dioxide toxicity, and the toxicity at 30 degrees C was 2.16 times of that at 15 degrees C. The toxicity of chlorine dioxide was significantly improved with the contact time increasing from 12 h to 24 h, while it did not make much difference with the contact time increasing to 36 h.