摘要
本试验定量研究了不同来源的有机物(腐植酸、无菌沉积物、沉积物和微生物提取物)对摇蚊属幼虫的疏水性农药毒死蜱[O,O-二乙基-O-(3、5、6-三氯-2-吡啶基)硫代磷酸酯]生物利用率的影响。在最后两步处理中,加入14C毒死蜱前可允许生物膜增殖。毒死蜱的累积量在浸渍25h和净化21h后分别定量检测。幼虫中的毒死蜱累积量在用微生物提取物(447±79μg/kgww的幼虫)处理中达到2倍,在用沉积物(371±33μg/kg)处理中达到1.7倍。净化后,幼虫组织中毒死蜱的累积量甚至表现出更大的差别,用微生物提取物(218±21μg/kg)处理后组织浓度达到3.1倍,用沉积物(156±35μg/kg)处理达到2.2倍;而用腐植酸和无菌沉积物处理后毒死蜱的累积量没有产生太大差别。这些结果表明:活体微生物和生物膜可以通过创造微生物环境和为幼虫提供食物,显著提高摇蚊属昆虫对毒死蜱的生物利用率。
In a microcosm study, the importance of different sources of organic matter（humic acids, sterile sediment, sediment, and a microbial extract） for the bioavailability of the hydrophobic pesticide chlorpyrifos to Chironomus riparius larvae was quantified. In the last two treatments biofilms were allowed to grow before 14C-chlorpyrifos addition. Chlorpyrifos accumulation was quantified after 25 h of exposure and after 21 h of depuration. Larval accumulation was twice as high in the microbial extract treatment（447±79 μg/kg ww larvae） and 1.7 times higher in the sediment treatment（371±33 μg/kg）. After depuration, chlorpyrifos accumulation in larval tissue showed even higher differences; 3.1 times higher tissue concentrations in the microbial extract treatment（218±21 μg/kg） and 2.2 times higher in the sediment treatment（156±35 μg/kg）. In contrast, chlorpyfifos accumulation in the humic acid and sterile sediment did not differ from that in controls. These results show that living microbes and biofilms, by creating a microenvironment and providing food for larvae, markedly increase the bioavailability of chlorpyrifos to Chironomus riparius.
出处
《腐植酸》
2009年第4期28-36,共9页
Humic Acid
