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Laboratory investigations of diclofenac migration in saturated porous media - a case study

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Okońska M. , Marciniak M. , Zembrzuska J. , Kaczmarek M.

2019

tom Vol. 25, No. 3

213--223

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.

Wpływ efektu skali eksperymentu kolumnowego na identyfikację parametrów migracji znaczników metodą rozwiązań analitycznych i modelowania numerycznego

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Marciniak M. , Okońska M. , Małoszewski P.

2006

tom Vol. 10

167--188

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.