Guber A K, Shelton D R, Pachepsky Y A, Sadeghi A M, Sikora L J
Department of Environmental Science, University of California, Riverside, A135 Bourns Hall, Riverside, CA 92521, USA.
Appl Environ Microbiol. 2006 Dec;72(12):7531-9. doi: 10.1128/AEM.01121-06. Epub 2006 Oct 6.
Modeling release of fecal coliforms is an important component of fate and transport simulations related to environmental water quality. Manure constituents other than fecal coliforms may serve as natural tracers of fecal contamination provided that their release from manure to runoff is similar to the fecal coliform release. The objectives of this work were to compare release of fecal coliforms (FC), chloride (Cl-), organic carbon (OC), and water-soluble phosphorus (P) from dissolving manure and to assess the performance of three models in describing the observed release. Bovine manure was applied on 0.5- by 0.3-m bare and vegetated subplots with 20% slope on sandy loam and clay loam soils. Concentrations of Cl-, FC, OC, and P were measured in runoff collected from troughs at the edges of the subplots at 5-min intervals during 1-h rainfall simulations. The one-parametric exponential model and two-parametric Vadas-Kleinman-Sharpley model and Bradford-Schijven model were fitted to the data. The Bradford-Schijven model had uncorrelated parameters, one of which was linearly related to the irrigation rate, and another parameter reflected the presence or the absence of vegetation. Kinetics of the FC release from manure was similar to the release kinetics of P and OC. The Bradford-Schijven model is recommended to simulate the release of manure constituents.
模拟粪大肠菌群的释放是与环境水质相关的归宿和迁移模拟的重要组成部分。除粪大肠菌群外，粪便中的其他成分可作为粪便污染的天然示踪剂，前提是它们从粪便向径流中的释放与粪大肠菌群的释放情况相似。本研究的目的是比较溶解粪便中粪大肠菌群（FC）、氯离子（Cl-）、有机碳（OC）和水溶性磷（P）的释放情况，并评估三种模型在描述观测到的释放情况方面的性能。在砂壤土和粘壤土上，将牛粪施用于坡度为20%、面积为0.5×0.3米的裸露和植被覆盖的小区。在1小时降雨模拟期间，每隔5分钟从小区边缘的水槽收集径流，测量其中Cl-、FC、OC和P的浓度。将单参数指数模型、双参数Vadas-Kleinman-Sharpley模型和Bradford-Schijven模型与数据进行拟合。Bradford-Schijven模型的参数不相关，其中一个参数与灌溉速率呈线性关系，另一个参数反映植被的有无。粪便中FC的释放动力学与P和OC的释放动力学相似。建议使用Bradford-Schijven模型来模拟粪便成分的释放。
