Fogg Paul, Boxall Alistair, Walker Allan, Jukes Andrew
Cranfield Centre for EcoChemistry, Shardlow Hall, Shardlow, Derby DE72 2GN, UK.
Pest Manag Sci. 2004 Jul;60(7):645-54. doi: 10.1002/ps.826.
Biobeds provide a potential solution to pesticide contamination of surface waters arising from the farmyard. Previous work has shown that biobeds can effectively treat spills and splashes of pesticide. This study investigated the potential for biobeds to treat much larger volumes and amounts of pesticide waste not only arising from spills but also from washing processes. Two systems were assessed using a range of pesticides at the semi-field scale, ie a lined biobed system and an unlined system. Studies using the lined biobeds demonstrated that water management was crucial, with biobeds needing to be covered to exclude rain-water. Once covered, the top of the biobed became hydrophobic, restricting moisture loss and resulting in saturated conditions at depth. The drying out of the top layer coincided with a measured decrease in microbial biomass in the treated biobeds. Applied pesticides were effectively retained within the 0-5 cm layer. Whilst all pesticides tested degraded, low moisture content and microbial activity meant degradation rates were low. Studies using unlined biobeds showed that only the most mobile pesticides leached, and for these > 99% was removed by the system, with a significant proportion degraded within 9 months. Peak concentrations of the two most mobile pesticides did however exceeded the limits that are likely to be required by regulatory bodies. However, it is thought that these limits could be reached by optimisation of the system.
生物床为解决由农家院产生的地表水农药污染问题提供了一种潜在的解决方案。先前的研究表明，生物床能够有效处理农药的溢出和飞溅。本研究调查了生物床处理不仅源于溢出而且源于清洗过程的更大体积和数量农药废物的潜力。在半田间规模下，使用一系列农药对两个系统进行了评估，即有衬里的生物床系统和无衬里的系统。使用有衬里生物床的研究表明，水分管理至关重要，生物床需要覆盖以排除雨水。一旦覆盖，生物床顶部就会变成疏水的，限制水分流失，导致深层处于饱和状态。表层变干与处理过的生物床中微生物生物量的测量减少同时发生。施用的农药有效地保留在0 - 5厘米的土层内。虽然所有测试的农药都发生了降解，但低水分含量和微生物活性意味着降解速率较低。使用无衬里生物床的研究表明，只有流动性最强的农药会发生淋溶，对于这些农药，系统去除率> 99%，且有很大一部分在9个月内降解。然而，两种流动性最强的农药的峰值浓度确实超过了监管机构可能要求的限值。不过，人们认为通过优化系统可以达到这些限值。
