The article describes an experiment involving pumping of groundwater from specific sections of the aquifer with a packer. The aim of the experiment was to identify the vertical differentiation of groundwater chemistry of the Wielkopolska Buried Valley Aquifer near Joanka well-field in order to explain the reasons for the occurrence of "brown water”. The research shows significant vertical and horizontal differences in groundwater chemistry. It has been found that “brown water” occurs in the lower part of the aquifer and its chemistry and isotopic composition imply origin from the Tertiary aquifer. It has been proved that the flow of “brown water” from Tertiary aquifer to the Wielkopolska Buried Valley Aquifer is possible through the old wrongly constructed well which was build before World War II. The hydrochemical data have been used to calibrate groundwater flow and contaminant transport model. This model has been used to determine the prognosis of “brown water” migration during well-field exploitation.
Soil erosion by water is influenced by a major morphogenetic factor – precipitation. Surface runoff, initiated by rainfall, plays a key role in this process. This article addresses the effects of rainfall intensity and soil moisture on soil erosion through a series of rainfall simulations of different intensity and duration. The implementation of measurements at a research station located in the Różany Stream catchment in Poznań made it possible to study the entire water balance within the slope, including precipitation, evaporation, surface runoff and infiltration. The study included various rainfall intensities, with a focus on extreme events reflecting ongoing climate change and increasing anthropopressure. Rainfall simulations were conducted on both dry and wet ground. The results showed that increasing rainfall intensity led to greater surface runoff and soil loss. Moreover, soil moisture was identified as a critical factor affecting soil erosion, with wetter conditions reducing soil loss while increasing surface runoff.
At present, concentrations of pharmaceuticals in surface and ground waters are low; however, even low concentrations of certain substances may prove very harmful. One of such pharmaceutical drugs is diclofenac, a popular non-steroidal anti-inflammatory drug (NSAID). For this reason, it is important to determine its mobility in groundwater and to estimate parameters of migration. Authors conducted column tests for two porous media: an artificial one, consisting of glass granules, and a natural one, i.e., sandur sand obtained from a site north of the city of Poznań (Poland). During the test, impulse breakthrough curves of chloride ions and diclofenac were recorded. The results were used to identify a specific sorption model and to determine values of migration parameters. Solutions of the inverse problem using optimisation methods and of equations of mathematical migration models were carried out in a MATLAB environment. Based on test results, the mobility of diclofenac is shown to be very high and comparable to that of chloride ions. The tests also revealed a slight and irreversible sorption of diclofenac on grains of both porous media.
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Laboratory investigations of an ion migration through a ground sample were carried out. The experiments were conducted with one kind of natural ground (semi-coarse sand) and with one solution containing two kinds of tracers. Chloride ions were used as a passive tracer, while lithium ions were applied as an active tracer. The experiments were performed by means of three various size filtration columns constructed by the authors. First the tracers were injected according to an increasing and decreasing Heaviside’s function, and then according to approximate Dirac’s function. As a result 18 tracer breakthrough curves through the examinated ground samples were registered. The experiment data allowed identifying such tracer migration parameters as: dispersivity a, distribution coefficient Kd and retardation factor R. The migration parameters’ values were determined by two methods: the analytical solution of a mathematical model describing experiment conditions, and the calibration of numerical model created by means of Visual MODFLOW and MT3D99 programs. As the research result a group of migration parameters’ values was received for each of the filtration columns. As the conclusion the authors discussed a scale effect on the basis of the migration parameters’ values obtained by the analytical and numerical identifications.
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