Showing papers by "Karin Müller published in 2014"

A new method to quantify how water repellency compromises soils' filtering function

Abstract: Summary Soil water repellency (SWR) is known to lead to preferential flow and to degrade the soil's filtering efficiency. However, no method is available to quantify directly how SWR affects the transport of reactive solutes. We propose a new method for conducting solute transport experiments in water-repellent soils. It involves sequentially applying two liquids, one water, the other a reference fully wetting liquid, namely aqueous ethanol, to the same intact soil core with air-drying between liquids. We applied this approach to quantify the impact of SWR on the filtering of the herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D) in two Andosols. In batch experiments conducted prior to the transport experiments, 2,4-D sorption was not influenced by aqueous ethanol for one soil. However, sorption in the second soil followed the co-solvency theory, which predicts decreasing sorption with increasing solvent fractions. Thus, sorption experiments are necessary to complement our new method. Breakthrough curves were characterized by preferential flow with large initial concentrations, tailing and a long prevalence of solutes remaining in the soil. In the soil in which 2,4-D sorption was unaffected by aqueous ethanol, SWR increased 2,4-D losses by four and 50 times in the first 5-mm outflow compared with the 2,4-D losses with water. After 50-mm outflow, the 2,4-D losses were similar for one core, but in the other core they were still about four times greater with water than with aqueous ethanol. This method to quantify the reduction of the soil's filtering efficiency by SWR is needed for assessing the increased risk of groundwater contamination by solutes exogenously applied to water-repellent soils.

Advances in Pesticide Risk Reduction

Abstract: Pesticides can potentially cause undesirable adverse side effects on nontarget organisms, humans, and the environment (soils, surface, and groundwater resources) because pesticides are toxic by design and are deliberately released into the environment. Pesticide risk is a combination of the (eco)toxicological properties of the pesticide and the potential exposure of humans, flora, and fauna to the pesticide. This article gives a general introduction to pesticide fate in the environment, summarizes risks associated with the production, use, and disposal of pesticides, and provides an overview on current strategies and tools to minimize these risks.

Characterization of water repellency parameters in soil water repellency characteristic curves for JP and NZ soils

Abstract: Subsurface Mass Transport and Environmental Assessment Convener:*Yasushi Mori(Graduate School of Environmental and Life Science, Okayama University), Hirotaka Saito(Department of Ecoregion Science, Tokyo University of Agriculture and Technology), Ken Kawamoto(Graduate School of Science and Engineering, Saitama University), Shoichiro Hamamoto(Department of Biological and Environmental Engineering, The University of Tokyo), Ming Zhang(Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology), Chair:Yasushi Mori(Graduate School of Environmental and Life Science, Okayama University), Ming Zhang(Institute for Geo-Resources and Environment, National Institute of Advanced Industrial Science and Technology) Wed. Apr 30, 2014 11:00 AM 12:44 PM 213 (2F) This session covers the topics on mass transport, waterand energy cycles in geoenvironment. Subjects related to laboratoryand field measurements, theoretical analysis, and numerical modelingwill be discussed. Presentations on geo-pollution, remediation,geological disposal of hazardous wastes, ground source heatutilization, mass transport in vadose zone, soil-water monitoring, andenvironmental assessment are encouraged.