Ünlü, Kahraman
This paper describes a screening model for evaluating the migration of organic and inorganic contaminants leached from land-disposed wastes. The model is composed of a waste-zone release submodel, an unsaturated-zone transport submodel and a saturated-zone transport submodel. The waste-zone submodel assumes steady one-dimensional vertical flow through a uniform waste zone treated as a "stirred tank reactor". Soluble inorganic contaminants are assumed to exhibit a constant concentration in the leachate until mass depletion occurs, while organic contaminants are assumed to exhibit leachate concentrations that are proportional to the mass fraction in the oily waste phase. Vertical, one-dimensional, unit-gradient flow is assumed in the unsaturated zone at a constant water content controlled by the net infiltration rate and the unsaturated soil permeability function. Transport occurs by convection and scale-dependent dispersion with linear adsorption and decay. In the saturated zone, flow is assumed to be planar, with three-dimensional convective-dispersive transport, adsorption and decay, with a rectangular horizontal source at the water table. The waste-zone submodel defines the boundary conditions for the unsaturated-zone submodel, which, in turn, defines the boundary conditions for the saturated-zone submodel. Because of the semi-analytical nature of the model, it can be executed very quickly, thus enabling rapid screening analyses and implementation in Monte Carlo analyses, which require a large number of model executions.


An Assessment of the Spatial Distribution of Polychlorinated Biphenyl Contamination in Turkey
Gedik, Kadir; İmamoğlu, İpek (Wiley, 2010-02-01)
This study summarizes the relevant information regarding the spatial distribution of polychlorinated biphenyls (PCBs) in various environmental (e.g., soil, sediment, air, water) and biological (e.g., fish, mussel, adipose tissue, milk) media in Turkey. The information sources, used for this purpose, in addition to the scientific literature, were; official import records, governmental reports on monitoring of organochlorines, and reports prepared by international organizations. PCBs were never produced in Tu...
Modeling biogeochemical dynamics in porous media: Practical considerations of pore scale variability, reaction networks, and microbial population dynamics in a sandy aquifer
King, E. L.; Tuncay, Kağan; Ortoleva, P.; Meile, C. (Elsevier BV, 2010-03-01)
Prediction of the fate and environmental impacts of groundwater contaminants requires the identification of relevant biogeochemical processes and necessitates the macroscopic representation of microbial activity occurring at the microscale. Using a well-studied sandy aquifer environment, we evaluate the importance of pore distribution on organic matter respiration in a porous medium environment by performing spatially explicit simulations of microbial metabolism at the sub-millimeter scale. Model results us...
SOYUPAK, S; KILIC, B; MUKHALLALATI, L; YURTERI, C (Informa UK Limited, 1993-01-01)
Long-term impacts of acidic depositions on soils can be predicted with coupled applications of acid deposition models and approaches to assess soil acidification. Soil acidification assessment can be achieved by using the following approaches: (i) Mechanistic modelling (ii) Experimental acid buffering capacity (ABC) method (iii) Qualitative evaluations The mechanistic modelling approach adopted in this study utilises predicted acid deposition rates and soil properties as well as dominant soil mechanisms inc...
A multi-technique approach to determine temporal and spatial variability of groundwater-stream water exchange
Koruk, Kasimcan; Yılmaz, Koray Kamil; Akyürek, Sevda Zuhal; Binley, Andrew (Wiley, 2020-04-03)
Characterizing the spatio-temporal distribution of groundwater-surface water (GW-SW) exchange fluxes is of paramount importance in understanding catchment behavior. A wide range of field-based techniques are available for such characterization. The objective of this study is to quantify the spatio-temporal distribution of the exchange fluxes along the cakit stream (Nigde, Turkey) through coupling a set of geophysical techniques and in-stream measurements in a hierarchical manner. First, geological and water...
Multiple-criteria calibration of a distributed watershed model using spatial regularization and response signatures
Pokhrel, Prafulla; Yılmaz, Koray Kamil; Gupta, Hoshin V. (Elsevier BV, 2012-02-08)
This paper explores the use of a semi-automated multiple-criteria calibration approach for estimating the parameters of the spatially distributed HL-DHM model to the Blue River basin, Oklahoma. The study was performed in the context of Phase 2 of the DMIP project organized by the Hydrology Lab of the NWS. To deal with the problem of ill conditioning, we employ a regularization approach that constrains the search space using information contained in a priori estimates of the spatially distributed parameter f...
Citation Formats
K. Ünlü, J. PARKER, D. STEVENS, P. CHONG, and I. KAMIL, “A SCREENING MODEL FOR EFFECTS OF LAND-DISPOSED WASTES ON GROUNDWATER QUALITY,” JOURNAL OF CONTAMINANT HYDROLOGY, pp. 27–49, 1992, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/56202.