|Opis:||The doctoral dissertation includes an assessment of the quality of data obtained by measuring physical and chemical parameters of groundwater. By means of chemometric characterisation we determined representativeness of monitoring points for groundwater monitoring programmes.
In studying, we applied chemometric methods such as analysis of variance, correlation analysis, cluster analysis, linear discriminant analysis, and principal component analysis.
Groundwater is the water under the ground surface, the source of more than 90% of drinking water in Slovenia. Groundwater is also the source of all natural mineral water and spring water in Slovenia. The dissertation relies on the results of national groundwater monitoring conducted by the Slovenian Environment Agency, the data about groundwater monitoring of the Ljubljana Municipality, the data on internal control of drinking water of the Maribor Waterworks and of the Murska Sobota Waterworks, the data from national drinking water monitoring, and the data from declarations of natural mineral water.
The parameters monitored in individual types of water differ: In groundwater and mineral water we observe basic parameters that define the basic mineral composition of water. In groundwater and potable water, we also determine pollutants, such as pesticides, halogenated organic solvents, aromatic hydrocarbons, total organic carbon, heavy metals, etc.
Water quality monitoring should provide reliable data and quality monitoring programmes have to be acceptable in terms of cost. On the one hand, laboratories are faced with ever greater requirements to lower the limit of quantitation for individual pollutants and assure quality, whereas on the other hand they are subject to economic pressure and competition from private and foreign laboratories.
The study examines the impact on sample classification due to the reduced number of samples and omitting parameters in the monitoring programme. We also assessed the adequacy of replacement of certain monitoring points both for potable and groundwater. Potable water supply systems can be simple (one water source, one water supply zone) or more complex (several water sources). The doctoral dissertation describes the methodology of monitoring the quality of drinking water and selection of monitoring points that would best reflect the characteristics of a water source and the effects of potential mixing of various water sources.
Special emphasis was put on assessing the quality of sampling and field measurements. We established that chemometric analyses can quickly tell us if measurements are reliable and correct or if there are any deviations in measurement results that we were unable to detect during routine work.
The dissertation proves the usefulness of chemometric methods for waters that are in the process of acquiring the title of “natural mineral water”. The legislation in this field is not completely specific. The methodology as to when water called “natural mineral water” differs from drinking water is not specified. The question as to whether this is the same water in certain cases can also be answered by means of chemometric methods.
In the classification of groundwater, we applied various chemometric methods. We established that linear discriminant analysis is especially useful, particularly for karst aquifers, where other methods have not resulted in expected classification. We can confirm that chemometric methods are an excellent tool in planning and streamlining the groundwater monitoring programme.|