- © 2002 AAPG/DEG
Biological activity in a dam containing an organic depository (the Hufeisen See region) in East Germany cleanses organic contaminants, by a factor of about a million, from water seeping through the dam to an outside lake. This article sets up several possible steady-state models to account for the observations, depending on whether the biologically active components are tied to sedimentary particles in the dam material or are free to move with the seeping water. Allowance is made for the death rate of the biological components and also for their variable growth rates. Numerical examples are provided to illustrate the patterns of response in the different cases possible for seepage speeds that are either fast or slow compared to the biological cleansing rate. Comparison with the data available from the Hufeisen See indicates that, while unique determinations of parameters and limitations on model possibilities are not yet possible, nevertheless it is possible to determine dependences of parameters in each model in order to be in accord with the observations. Allowing for the known uncertainty in the measured data of contaminant concentration ratio, from the interior to exterior of the depository, permits an assessment to be made of the range of uncertainty of parameter relations. For the Hufeisen See depository it is shown that the uncertainty is relatively small in comparison to mean values of parameter relations. The overall implication is that the choice of appropriate model cannot yet be better constrained without new measurements of relative organic concentration through and in the dam material itself.
Ian Lerche is Professor of Geology at the University of South Carolina. His current major research interests are in the fields of basin analysis, salt, economic risk, and environmental problems. He has published several hundred papers, more than a dozen books. He is the recipient of numerous awards and honors, including the Levorsen Award of the AAPG. Currently, he sits on several editorial boards and is also technical editor of Energy Exploration & Exploitation.
Dr. Walter A. E. Glaesser has been associated with the University of Halle, East Germany, since 1962 and is currently the Head of the Department of Hydrogeology of the Centre for Environmental Research Leipzig. Dr. Glaesser also served as a geologist with the Government Department of Geology in Leipzig from 1967 to 1982, and Full Professor of Geology and Hydrogeology at the University of Leipzig, Department of Geophysics and Geology in 1995. Dr. Glaesser specialized in engineering and environmental geology and hydrogeology.
Dr. Gerhard Strauch received his Ph.D. in 1973 at the Technische Hochschule Merseburg from 1966 to 1973. Dr. Strauch was a research Scientist at the Central Institute for Isotope and Radiation Research Leipzig from 1973 to 1991, while engaged in theoretical and experimental studies of stable isotopes in natural systems. Since 1992 Research Scientist at the Department of Hydrogeology of the Center for Environmental Research Leipzig-Halle Ltd where he is involved in project management for studies in isotope geochemistry and hydrogeology.