Dynamic Processes in Capillary Fringes

Abstract

CSA NewsVolume 60, Issue 6 p. 23-23 News & PerspectiveOpen Access Dynamic Processes in Capillary Fringes First published: 09 June 2015 https://doi.org/10.2134/csa2015-60-6-8AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL The May 2015 issue of Vadose Zone Journal features a special section on processes in capillary fringes, with a focus on the complex interaction of biological, chemical, and physical processes in this environemnt. Capillary fringes are highly dynamic and periodically changing zones at the interface between the water-saturated aquifer and the unsaturated zone. As a consequence, we observe steep gradients in terms of hydraulic state variables, biogeochemical conditions, and thus, biological activity (Berkowitz et al., 2004). With fluctuations of the groundwater table, this reactive zone moves dynamically along the vertical direction, further complicating our understanding of specific processes that occur in both space and time. This special compartment is not only an interesting and challenging subject of research, it is also highly relevant for mass fluxes with terrestrial systems (Silliman et al., 2002; Haberer et al., 2011) and especially the biodegradation of contaminants (Lahvis et al., 1999; Dobson et al., 2007). To gain a comprehensive understanding of the mass transfer and transformation in the CF, the close interactions of physical, chemical, and biological processes call for an interdisciplinary approach. This was the motivation to establish the interdisciplinary research group DyCap, funded by the Deutsche Forschungsgemeinschaft for a period of 6 years. The aim was to explore the basic physical, (hydro-)geological, chemical, and microbiological processes in CFs and their interaction, while collaborating closely with an interdisciplinary team of researchers. This special issue contains some of the latest results of DyCap, together with other actual research related to the dynamics of capillary fringes. This special issue presents examples of complex processes within capillary fringes. The contributions demonstrate the intensive coupling of biological, chemical, and physical processes relevant for a profound understanding of mass fluxes and turnover within this hot spot at the surface of the groundwater table. We hope these papers and increased knowledge will inspire future research on dynamic capillary fringes. References Berkowitz, B., Silliman, S.E., and Dunn, A.M. 2004. Impact of the capillary fringe on local flow, chemical migration, and microbiology. Vadose Zone J. 3: 534– 548. https://doi.org/10.2113/3.2.534 Dobson, R., Schroth, M.H., and Zeyer, J. 2007. Effect of water-table fluctuation on dissolution and biodegradation of a multi-component, light nonaqueous-phase liquid. J. Contam. Hydrol. 94: 235– 248. https://doi.org/10.1016/j.jconhyd.2007.07.007 Haberer, C.M., Rolle, M., Liu, S., Cirpka, O.A., and Grathwohl, P. 2011. A high-resolution non-invasive approach to quantify oxygen transport across the capillary fringe and within the underlying groundwater. J. Contam. Hydrol. 122: 26– 39. https://doi.org/10.1016/j.jconhyd.2010.10.006 Lahvis, M.A., Baehr, A.L., and Baker, R.J. 1999. Quantification of aerobic biodegradation and volatilization rates of gasoline hydrocarbons near the water table under natural attenuation conditions. Water Resour. Res. 35: 753– 765. https://doi.org/10.1029/1998WR900087 Silliman, S.E., Berkowitz, B., Šimůnek, J., and Genuchten, M.T. 2002. Fluid flow and solute migration within the capillary fringe. Ground Water 40: 76– 84. https://doi.org/10.1111/j.1745-6584.2002.tb02493.x Volume60, Issue6June 2015Pages 23-23 ReferencesRelatedInformation