Raziskava karbonatnega ravnotežja vode s stabilnim izotopom ogljika (zgoraj 13 C) : doktorska disertacija

slovenian

doktorska dela

2009

Univerza v Mariboru, Fakulteta za strojništvo

Various origin and different geochemical and biological processes influence the wide variety and complex composition of natural waters. Different organic and inorganic components give water better quality, but at the same time theirchemical reactionsć products can damage the water pipe systems. Water of optimal quality for human consumption should not be corrosive in waterworks neither form limestone deposits. Therefore, the water has to be kept in a thermodynamic balance with the mineral phases of calcite and aragonite, besidethe appropriate pH value and alkalinity in order to fulfil this condition. The optimal carbon dioxide content, which is the usual component ofhealthy drinking water, simultaneously prevents from precipitated mineral deposits and corrosion. The presented doctoral dissertation is focused to the development of advanced method for water quality optimization using carbon dioxide gas, the construction of hydrochemical model for process simulation inhigher temperature range and the study of carbonate species distribution by *CO2 special isotopic gas (ä13C = -35,2 %) application. Based on the latter, ävalues of prevalent carbonate species (bicarbonate ion, . 3 HCO ) are determined along with GC IRMS (gas chromatography coupled with mass spectroscopy for determining isotopic ratios) and corresponding mole fractionsare calculated. Obtained results served for evaluation of method efficiency. On the basis of experimental work, using the stable carbon isotopegas *CO2 as marker, we can conclude that added gas is present in composition of almost half of all bicarbonate ions. The ultrasonic stirrer used during the entire experiment decreases the method efficiency by 14 %, butspeed up the CO2 dissolving process in early experiment stages.

08.08.2023