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Full-Text Articles in Physical Sciences and Mathematics
Modeling Transport Of Colloid-Bound Herbicides And Heavy Metals To Groundwater, Anastasios D. Karathanasis, R. E. Phillips, A. K. Seta
Modeling Transport Of Colloid-Bound Herbicides And Heavy Metals To Groundwater, Anastasios D. Karathanasis, R. E. Phillips, A. K. Seta
KWRRI Research Reports
Recent studies have suggested that contaminant transport to groundwater may be enhanced by association with colloidal particles. This study evaluated the role of water dispersible colloids with diverse mineralogical composition in co-transporting selected herbicides and heavy metals through intact soil columns. Colloid recovery in the eluents ranged from 45-90% for the herbicides and 10-60% for the heavy metals. The presence of colloids enhanced the transport of atrazine by 2-18%, and metolachlor by 8-30%. The corresponding increase for Cu and Zn was 2-150 and 5-30 times, respectively. For Pb, there was essentially no elution in the absence of colloids, suggesting nearly …
A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards
A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards
Biosystems and Agricultural Engineering Faculty Publications
Accurately predicting the rainfall-runoff process is of vital importance for water quality models as well as for correct design of various types of hydraulic structures. This article presents a method of describing the cumulative infiltration process as an explicit function of time using an approximation to the modified Green-Ampt equation given by Mein and Larson (1971). The resulting equation is helpful in predicting cumulative infiltration and therefore infiltration capacity for computer simulation models. The proposed method takes about 50% less time than the usual iterative technique for the same degree of accuracy. The maximum error due to approximation was 1% …
Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr.
Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr.
Biosystems and Agricultural Engineering Faculty Publications
Runoff transport of phosphorus (P) is often predicted from simple equations with parameters determined from data applicable primarily to row-cropped and fallow cover conditions. The applicability, accuracy, and precision of such P transport prediction equations under pasture situations are less well defined. The objectives of this study were to determine parameters of simplified runoff P transport equations for pasture fields and to assess the accuracy and precision of the equations. Runoff, sediment yield, soluble P transport, and particulate P transport data were collected from four pasture fields in northwestern Arkansas. Runoff event enrichment ratios and extraction coefficients were computed, and …