The fate of isoproturon in a freshwater microcosm with Lemna minor as a model organism

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• 作者：Thomas Bö ; ttcher ; Reiner Schroll
• 关键词：Isoproturon ; Lemna minor ; Aquatic system ; Mineralisation ; Volatilisation ; Bioconcentration factor
• 刊名：Chemosphere
• 出版年：2007
• 出版时间：January 2007
• 年：2007
• 卷：66
• 期：4
• 页码：684-689
• 全文大小：160 K

文摘

Degradation, bioaccumulation and volatile loss of the ¹⁴C-labeled phenylurea herbicide isoproturon (IPU) was examined in a freshwater microcosm with the free floating macrophyte species Lemna minor during a 21-day exposure time. Isoproturon volatilisation was very low with 0.13 ± 0.01 % of the initially applied herbicide. Only a minor amount of the herbicide was completely metabolised, presumably by rhizosphere microorganisms and released as ¹⁴CO₂. In total, about 9 % isoproturon was removed from the aquatic medium during 21 days. The major portion of the pesticide was removed by bioaccumulation of Lemna minor (5.0 ± 0.8 % ) and the bioconcentration factor (BCF) based on freshweight was 15.8 ± 0.2. However, this study indicated a high persistence of IPU in freshwater ecosystems and a potential hazard due to bioaccumulation in non-target species. The novel experimental system of this study, developed for easy use and multiple sampling abilities, enabled quantitatively studying the fate of isoproturon and showed high reproducibility with a mean average ¹⁴C-recovery rate of 97.1 ± 0.7 % .