Department of Civil Engineering, University of Minnesota, 500 Pillsbury Drive Southeast, Minneapolis, Minnesota 55455, USA.
Environ Sci Technol. 2011 Aug 15;45(16):6814-22. doi: 10.1021/es200812e. Epub 2011 Jul 26.
Prairie pothole lakes (PPLs) are located within the extensively farmed Great Plains region of North America, and many are negatively impacted by nonpoint source pesticide pollution. To date, the environmental fate of pesticides in these lakes remains largely unknown. In this study, two PPLs in the Cottonwood Lake area of North Dakota were sampled, and transformations of four chloroacetanilide pesticides in sediment porewaters were examined. The reduced sulfur species in the porewaters, such as bisulfide (HS(-)) and polysulfides (S(n)(2-)), readily transformed the target pesticides into sulfur-substituted products. Although HS(-) and S(n)(2-) played a dominant role, other reactive constituents in PPL porewaters also contributed to the transformation. Results from this study revealed that abiotic reactions with reduced sulfur species could represent an important removal pathway for pesticides entering PPLs.
草原洼地湖泊（PPLs）位于北美广泛耕种的大平原地区，许多湖泊受到非点源农药污染的负面影响。迄今为止，这些湖泊中农药的环境归宿在很大程度上仍不清楚。在这项研究中，对北达科他州棉白杨湖地区的两个 PPL 进行了采样，并研究了沉积物孔隙水中四种氯乙酰胺类农药的转化情况。孔隙水中的还原性硫物种，如 硫氢根（HS(-)）和多硫化物（S(n)(2-)），很容易将目标农药转化为硫取代产物。尽管 HS(-)和 S(n)(2-) 起主要作用，但 PPL 孔隙水中的其他反应性成分也促成了转化。本研究结果表明，与还原性硫物种的非生物反应可能是进入 PPL 的农药的一个重要去除途径。
