Moore M T, Kröger R, Cooper C M, Smith S
USDA-ARS National Sedimentation Laboratory, P.O. Box 1157, Oxford, MS 38655, USA.
Arch Environ Contam Toxicol. 2009 Aug;57(2):282-8. doi: 10.1007/s00244-009-9334-7. Epub 2009 May 21.
Increased focus is being placed on the ability of native vegetation to mitigate potential harmful effects of agricultural runoff, especially pyrethroid insecticides. Replicate 379 L Rubbermaid tubs (1.25 m [l] x 0.6 m [w] x 0.8 m [h]) were planted with individual species of cutgrass (Leersia oryzoides), cattails (Typha latifolia), bur-reed (Sparganium americanum), and powdery alligator-flag (Thalia dealbata), all common wetland macrophytes found in the Mississippi Delta, USA, agricultural region. Permethrin-enriched water (target concentration, 5 microg L(-1)) was pumped in at a 4-h hydraulic retention time at one end of the tub and discharged at the far end. Water samples were collected from discharge at 1-h intervals for 12 h and analyzed for permethrin concentrations. Permethrin removal rates were compared for the four different plant treatments and nonvegetated sediment-water controls. Results indicated that no particular single plant species was more effective at removing permethrin in water relative to unplanted controls. Overall mass reductions (from inflow to outflow) for cis-permethrin ranged from 67% +/- 6% in T. latifolia to 71% +/- 2% in L. oryzoides. The trans-permethrin overall mass reductions ranged from 76% +/- 4% in S. americanum to 82% +/- 2% in the unplanted control. Sediment and plant samples collected at the study conclusion indicated that 77%-95% of measured permethrin mass was associated with sediment for mesocosms planted with L. oryzoides, T. latifolia, and T. dealbata. Conversely, mesocosms planted with S. americanum had 83% of measured mass associated with the plant material. Specific plant-pesticide retention studies can lead to improved planning for best management practices and remediation techniques such as constructed wetlands and vegetated agricultural drainage ditches.
人们越来越关注本地植被减轻农业径流潜在有害影响的能力，尤其是拟除虫菊酯类杀虫剂。使用379升的可重复使用的Rubbermaid塑料桶（长1.25米×宽0.6米×高0.8米），分别种植了碎米莎草（李氏禾）、香蒲（宽叶香蒲）、黑三棱（美洲黑三棱）和粉绿狐尾藻（粉绿狐尾藻），这些都是美国密西西比三角洲农业区常见的湿地大型植物。将富含氯菊酯的水（目标浓度为5微克/升）以4小时的水力停留时间从桶的一端泵入，并在另一端排出。在12小时内每隔1小时从排放口采集水样，分析氯菊酯浓度。比较了四种不同植物处理和无植被沉积物 - 水对照的氯菊酯去除率。结果表明，相对于未种植的对照，没有一种特定的单一植物物种在去除水中氯菊酯方面更有效。顺式氯菊酯的总体质量减少量（从流入到流出）在宽叶香蒲中为67%±6%，在李氏禾中为71%±2%。反式氯菊酯的总体质量减少量在美洲黑三棱中为76%±4%，在未种植的对照中为82%±2%。在研究结束时采集的沉积物和植物样本表明，对于种植了李氏禾、宽叶香蒲和粉绿狐尾藻的中宇宙，77% - 95%的测量氯菊酯质量与沉积物相关。相反，种植美洲黑三棱的中宇宙有83%的测量质量与植物材料相关。特定的植物 - 农药保留研究可以改进最佳管理实践和修复技术（如人工湿地和植被化农业排水沟）的规划。
