HR: 0802h
AN: NS11C-0693    [Abstracts]
TI: Low Frequency Electrical Measurements of Unsaturated Filters for Wastewater Treatment
AU: * Forquet, N
EM: nicolas.forquet@engees.u-strasbg.fr
AF: ENGEES-SHU, 1 quai Koch B.P. 61039, STRASBOURG Cedex, 67070, France
AU: French, H
EM: helen.french@bioforsk.no
AF: Norwegian Institute of Agriculture and Environmental Research Bioforsk, Soil and Environment Division, Frederik A. Dahlsvei 20, Aas, 1432, Norway
AU: Binley, A
EM: a.binley@lancaster.ac.uk
AF: Lancaster Environment Centre, department of Environmental Science, Lancaster University, Lancaster, LA14YQ, United Kingdom
AU: haugen, L
EM: lars.haugen@umb.no
AF: IPM, UMB, UMB, box 5003, Aas, 1432, Norway
AB: On-site wastewater treatment such as infiltration systems are used extensively for small communities all over Europe. For instance in France, the number of vertical flow constructed wetland has increased from 0 to more than 400 units between 1992 and 2005. There is a lack of relevant tools for monitoring their functionality and detecting potential failures in the systems. Electrical Resistivity Tomography (ERT) combined with Induced Polarization (IP) could potentially provide such a tool. Preliminary field studies have indicated that spatial variability in the flow pattern can be revealed by time-lapse measurements of electrical resistivity, however the interpretation of these results require better knowledge about the constitutive relationship between electrical properties and water content, water conductivity and biological clogging in typical filter media. A laboratory experiment was conducted using a four-electrode arrangement in soil sampling cylinders. Under controlled water contents the electrical resistivity and IP was measured for different levels of water conductivity and biofilm development. Finally, results were compared with empirical and theoretical relationships found in the literature, and the reliability of these methods for monitoring in wastewater treatment systems evaluated.
DE: 1835 Hydrogeophysics
SC: Near-Surface Geophysics [NS]
MN: 2007 Fall Meeting