Supervisors info:
Μιχαήλ Σταματάκης, Καθηγητής, Γεωλογίας και Γεωπεριβάλλοντος, Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών
Summary:
The current thesis negotiates the potentiality of some mixtures of pulverized Mg-rich carbonates (magnesite, dolomite, hydromagnesite, huntite), Mg-hydroxides (brucite) and some Ca-rich carbonates (aragonite and calcite) of natural occurrence to be used as soil amendments that provide Mg2+ to the environment with slow release, and secondarily Ca2+ (huntite, hydromagnesite) as well as elevation of its’ pH. Most of the Mg-rich raw materials used for the experiment were selected from the field, which was located at Kozani Basin in Western Macedonia (Fig. 1 and 3), and some of them were commercial products and processing waste that were delivered for the experiment from the companies producing them. The materials were then divided into six (6) main samples and recognition of the mineral phases and their participation in the samples was made with X-ray diffraction analysis and SEM (Scanning Electron Microscope) spectroscopy. The environment of the conducted experiment was composed of loam soil (USDA soil classification triangle) or sandy mud (Folk soil classification triangle, 1954) of 5.5 pH and bottled mineral water. To conduct the experiment the raw materials were pulverized and then shaped into pellets so that they could be mixed with the soil in specific ratios. The experiment went on by adding a precise amount of bottled mineral water to the solid mixture, leaving the arrangement as it was for specific periods of time and eventually collecting the same amount of water from each sample for each period. By measuring the Mg2+ concentration in each solution with FAAS (Flame Atomic Absorption Spectroscopy), the calculation of the amount of Mg (mg) that was released from each pelletized sample in relation with time was possible. The concentration of Ca2+ in each solution was also measured with the volumetric measurement method, and the amount of Ca (mg) released from each pelletized sample versus time was calculated as well. The experiment revealed that there was no salt accumulation in the soil, and that samples which were huntite/hydromagnesite-rich, were the ones to release the highest amounts of Mg2+ and Ca2+ in total. In particular, the quarry’s processing waste that were delivered, revealed excellent results and the industrial potential for soil amending uses, for acid soil remediation.
Keywords:
Magnesium carbonates, Huntite, Hydromagnesite, Soil amendments, Kozani Basin, Rate of ion release, Soil remediation
