Download or read book Cation Exchange and Transport in Soil Columns Undergoing Miscible Displacement written by Sung-ho Lai and published by . This book was released on 1970 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mathematical model was developed to predict the exchange of one cation by another in a soil column undergoing one dimensional cation solution displacement under steady state flow conditions. The model allowed prediction of both the solution and exchanger phase concentration of the cation in question. The model consists of a material balance equation which is a parabolic type partial differential equation. The assumption was made that equilibrium was reached instantaneously between the cations in the solution phase and the exchanger phase. This assumption reduced the material balance equation to a form that allowed numerical solution providing the data concerning the cation exchange isotherm and the initial and boundary conditions are available. FORTRAN programs were written for the numerical computation of the problem involved. The computation was done on a digital computer. The model was verified by comparing the theoretically computed cation concentration profile with data from actual soil column experiments. The cation exchange of Mg1́œÌ12́2Ca was tested on Yolo fine sandy loam, Nibley clay loam and Haford Sandy loam columns. The exchange of Na1́œÌ12́2Ca was also tested on Yolo fine sandy loam. Satisfactory agreement between the column experiment values and the theoretically computed values was obtained.
Download or read book Miscible Displacement and Cation Exchange in Saturated and Unsaturated Soil Columns written by Ozdemir Beyce and published by . This book was released on 1964 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cation Transport in Soils and Factors Affecting Soil Carbonate Solubility written by J. J. Jurinak and published by . This book was released on 1973 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unsaturated Transport of Inorganic Cations in Undisturbed Soil Columns written by and published by . This book was released on 1990 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The unsaturated transport of Sr, Co, and Ca were studied in undisturbed soil columns (14 x 40 cm) of saprolitic shale to evaluate the significance of time dependent mass transfer and multispecies competitive exchange during transport. Observed breakthrough curves (BTCs) for Sr and Co were delayed relative to nonreactive Br BTC indicating that the former tracers were adsorbed by the soil. Effluent concentrations of Sr and Co were modeled with the classical convective dispersive (CD) equation and nonequilibrium mass transfer considerations did not appear necessary. Cation exchange equilibria relationships obtained from both shake batch and miscible displacement methods adequately described the thermodynamic processes which were prevalent during transport. These results suggest that the preferential transport of a reactive tracer is negligible for the realistic unsaturated conditions used in the study, and that the massive saprolite within the soil is a chemically active constituent during transport of reactive solutes. The implications of these findings for modeling in-situ subsurface contaminant transport are discussed. 7 refs., 9 figs.
Download or read book Research Reporting Series written by and published by . This book was released on 1973 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Movement of hazardous substances in soil written by Emily D. Copenhaver and published by . This book was released on 1979 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EPA 600 9 written by and published by . This book was released on 1979-08 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Herbicide Contamination of Surface Runoff Waters written by John O. Evans and published by . This book was released on 1973 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: Field and laboratory studies of the movement of herbicides were conducted to determine their potential as contaminants in irrigation return flow. Special emphasis was given to the use of herbicides for vegetation control along ditches, canals and watersheds where high dosages are required to control the excessive growth of grasses and broadleaved weeds. The following herbicides have been studies: substituted urea (diuron), triazines (summitol and atrazine), phenoxyacetic acid (2, 4-D and 2, 4, 5-T) and a substituted pyridine (picloram). The greatest tendency for transport of herbicides in water coming in contact with soils occurs during the initial storms following spray application. If the intensity of the initial precipitation is not sufficient to cause movement across the soil, the danger of herbicide movement is essentially eliminated. The highest concentratoins (ppm) of herbicide observed in surface waters were 1.8, 0.5, 4.2 and 2.7 for diuron, summitol, 2, 4-D, 2, 4, 5-T and picloram, respectively. These levels were observed immediately below treated areas receiving the higher recommended dosages of the herbicides. All herbicide concentrations dropped below the limit of detection within a few hundred meters below the sprayed areas. Presumably, soil filtration, adsorption and dilution are primarily responsible for the loss of herbicides from water.
Download or read book Movement of Hazardous Substances in Soil Selected metals written by Emily D. Copenhaver and published by . This book was released on 1979 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prediction Modeling for Salinity Control in Irrigation Return Flows written by Arthur G. Hornsby and published by . This book was released on 1973 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book EPA 600 2 written by and published by . This book was released on 1972 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrodynamics of Calcium arrow Sodium Exchange in Soil Columns written by Arturo Cornejo and published by . This book was released on 1971 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Selected Irrigation Return Flow Quality Abstracts 1972 1973 written by Gaylord V. Skogerboe and published by . This book was released on 1974 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Waste Treatment System for Confined Hog Raising Operations written by William R. Park and published by . This book was released on 1974 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applicability of Boyd s Exchange Equations to Cation Exchange in Soil Columns written by Emmet Lewis Greacen and published by . This book was released on 1949 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transport of Hazardous Substances Through Soil Processes Arsenic beryllium cadmium chromium copper cyanide lead mercury selenium zinc and others written by Emily D. Copenhaver and published by . This book was released on 1974 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Miscible Displacement of Nitrate and Chloride Through Soil Columns written by John Charles Corey and published by . This book was released on 1966 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
