Download or read book Separating the Physical and Chemical Effects of Soil Organic Matter on the Fate of Atrazine in Soil Aggregates written by Undrea Nicole Hardaway and published by . This book was released on 1999 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Impact of Soil Organic Matter Heterogeneity and Soil Aggregation on the Sorption of Herbicides by Soils written by and published by . This book was released on 2007 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments were performed in pursuit of understanding of interactions between herbicides and soils, focusing on the effects of heterogeneity within soil organic matter (SOM), and the aggregation of SOM with mineral matter in soils, on equilibrium sorption and sorption rates of herbicides. For this purpose, sorption of three herbicides -- atrazine, metolachlor and napropamide -- was studied on a bulk soil, a bulk peat and three fractions that were chemically isolated from it. Studies were also performed using the well studied polynuclear aromatic hydrocarbon (PAH) phenanthrene to provide a comparison for the herbicides. The sorbents extracted from the soil and peat -- Base extracted fraction (BE), humic acids fraction (HA) and kerogen and black carbon fraction (KB) were characterized with elemental analysis, scanning electron microscopy and surface area measurements and subjected to sorption and desorption equilibrium studies and sorption rate investigations. The herbicides were found to exhibit non linear sorption isotherms on all the sorbents, with HA from both soil and peat showing the least non linear isotherms and fastest sorption rates among all the sorbents. HA fraction also showed the least dependence of equilibrium or time dependent organic carbon normalized sorption capacity (KOC or KOC(t)) on initial aqueous solute concentration. This result was in accordance with the amorphous nature of the HA material and similar to that observed for PAHs. Herbicide atrazine was found to react with HA and was transformed to hydroxyatrazine in its presence. KOC or KOC(t) values for all other sorbents were found to be dependent on initial aqueous solute concentration. High sorption capacity of KB dominated the sorption for all the herbicides, with this capacity being diminished by the aggregation structure of the soil. Significant sorption hysteresis was not observed for the sorption of herbicides on the KB fraction, unlike that observed for phenanthrene, indicating large herbicide molecules do not penetrate nanopores of KB. Hysteresis observed for the bulk soil and BE for atrazine was attributed to chemical interactions between the sorbents and the herbicide. Overall this dissertation found that the herbicides exhibit hydrophobic interactions with soils, similar to PAHs, but owing to their large molecular sizes and polarities may exhibit site specific interactions and lack of hysteresis with soil components that call for changes in existing fate and transport models and further microscopic understanding.

Download or read book Biodegradation of Atrazine in Subsurface Environments written by Jim Sinclair and published by . This book was released on 1992 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Separation of ecological meaningful soil organic matter fractions using chemical and physical methods potentials and pitfalls written by Michael Kaiser and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical Separation and Characterization of Soil Organic Matter Fractions written by Cynthia A. Cambardella and published by . This book was released on 1992 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Annual Meetings Abstracts written by American Society of Agronomy and published by . This book was released on 1999 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fate of Atrazine in Argentinean Soils written by Susana Hang and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book are shown the results of the atrazine behavior in Argentinean, conducted between 2001 and 2006. In the first work it was studied the behavior of atrazine in surface soils, and evaluated the effect of land use and how it affects the ability of soil to remove residual atrazine. In the second study it was evaluated two soil profiles characteristic of the province of Cordoba, and in each horizon, the effect of soil properties on the retention and degradation of atrazine mineralization was evaluated. The third study aimed to recognize the distribution along the profile of the soil's ability to mineralize atrazine. The soil sterilization was carried out to quantify chemical and biological degradation of atrazine. In the fourth and fifth paper it was analyzed different strategies of winter weed control and how weed management influenced on the atrazine persistence. In the sixth and final paper it is presented an original proposal to identify soils with rapid mineralization capacity of atrazine, based in corn crop history where atrazine is used. As a tool to reconstruct the history of the lot was used satellite images.

Download or read book Fate and Persistence in Soil of Selected Toxic Organic Chemicals written by Roxanne Breines Sukol and published by . This book was released on 1987 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt: The environmental fate and behavior of several toxic organic materials are reviewed in the final report on which this summary is based. This effort has sought to summarize the chemical and physical properties of these materials, and discusses how these properties affect persistence and behavior of toxic chemicals in the soil/water/air systems. In general, the organic carbon content of a soil has the greatest effect on the behavior of hydrophobic toxic organic compounds. The organic compounds sorb strongly to the organic matter in the soil. Several equations have been derived that define water solubility relationships. These are partition coefficients between octanol/water and organic mater/water. Persistence of the toxic organic compounds depends on several environmental factors, including soil organic matter, total precipitation and intensity, temperature, sunlight intensity, and soil texture. Organic chemicals are subject to one or more of seven possible fates: (1) sorption, (2) volatilization, (3) microbial degradation, (4) photodecomposition on the soil surface, (5) translocation to plants, (6) chemical degradation, and (7) leaching to ground water. Some of these fates are directly related to the degree of sorption; i.e., very little of a material that is strongly sorbed will be in solution and available for degradation or movement by the other processes. Some generalities are presented regarding the environmental conditions and chemical/physical properties that affect persistence and mobility; however, the reader should bear in mind that there are always exceptions to the rule.

Download or read book Environmental Fate of Two Herbicides in Soils written by Amrith S. Gunasekara and published by . This book was released on 2007 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Aggregation and Organic Matter Decomposition written by Gordon Chesters and published by . This book was released on 1959 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aging of 14C labeled Atrazine Residues in Soil Location Characterization and Biological Accessibility written by Nicolai David Jablonowski and published by Forschungszentrum Jülich. This book was released on 2009 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Chemical Treatment for Organic Matter Removal on Mineral Soil Constituents written by Adelina Siregar and published by . This book was released on 2004 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Various Soil Factors and Amendments on the Degradation of Pesticide Mixtures in Waste Disposal Systems written by Sarah Roati Schoen and published by . This book was released on 1985 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atrazine soil Organic Matter Relationships and Methodology for Determination of Atrazine Residues written by Edward P. Dunigan and published by . This book was released on 1967 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of PH Organic Matter and Zinc Metal on the Degradation of Pesticides in Model Soil Disposal Systems written by David Melvin Hodapp and published by . This book was released on 1992 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atrazine Degradation in Soil written by David E. Armstrong and published by . This book was released on 1966 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sorption and Degradation of Pesticides and Organic Chemicals in Soil written by Daniel M. Linn and published by . This book was released on 1993 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reports the current thinking on the role that adsorption may play in the rate and extent of an organic compound's degradation in the soil. Among the topics of the 14 papers are diazinon degradation and dissipation in the root zone, the reductive dechlorination of hexachlorobenzene in wetland soils, and the utility of sorption and degradation parameters from the literature for site-specific pesticide impact assessments. Proceedings from an October 1991 symposium in Denver. No index. Annotation copyright by Book News, Inc., Portland, OR