Taloženje kalcijeva karbonata u umjetnoj krškoj vodi uz dodatak odabranih okolišnih i antropogenih molekula

doctoral thesis

• Title (english): The effect of selected environmental and anthropogenic molecules on calcium carbonate precipitation in artificial karst water
• Author: Nives Matijaković Mlinarić
• Mentor: Damir Kralj (mentor)
• Committee member: Marijana Đaković (predsjednik povjerenstva)
• Committee member: Tajana Begović (član povjerenstva)
• Committee member: Ana Šantić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2021-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

U ovom radu sustavno su, kroz dulji period, provedene fizičko-kemijske analize krške vode i sedre na odabranim lokacijama Nacionalnog parka Plitvička jezera. Zbog intenzivne mineralizacije, visokog pH i prezasićenosti kemijski sastav krške vode na jezeru Novakovića brod odabran je kao najreprezentativniji za usporedbu taloženja u prirodi te u laboratorijskim uvjetima, u umjetnoj krškoj vodi. Korištenjem standardnog laboratorijskog modela taloženja kalcijeva karbonata (CaCO3), sustavno je istražen utjecaj okolišnih molekula (huminska kiselina, HA i fulvinska kiselina, FA) i antropogenih iona (fosfat, PO43− i polifosfat, (PO3−)n) na taloženje CaCO3. Pokusima spontanog taloženja u rasponu temperatura, 10 °C < θ < 25 °C, utvrđeno je da dodani aditivi mijenjaju morfologiju i polimorfni sastav taloga te da inhibiraju nastanak vaterita i aragonita u nizu: (PO3−)n > (FA ≈ HA) > PO43−. Pri nižim temperaturama taloži manja količina CaCO3, a uz dodatak viših koncentracija PO43− i (PO3−)n taloženje CaCO3 je u potpunosti inhibirano. Za istraživanja mehanizma rasta kristala također je korištena umjetna krška voda, kao i prethodno pripravljeno kristalno sjeme romboedarskog {104} kalcita te pločastog kalcita s dominantnim {001} plohama. Analizom kinetičkih mjerenja, θ = 20 °C, utvrđeno je da se rast kristala {104} kalcita i {001} kalcita zbiva na spiralnoj dislokaciji te da je rast {104} kalcita znatno brži od rasta {001} kalcita. Okolišni i antropogeni aditivi uzrokuju inhibiciju rasta, kako {104} tako i {001} kalcita u nizu: (PO3−)n > (FA ≈ HA) > PO43−. Također, uz dodatak aditiva mijenja se mehanizam procesa rasta kristala kalcita te on postaje kontroliran procesom površinske nukleacije.

Abstract (english)

In this disertation, the physico-chemical analyzes of karst water and travertine were performed in the Plitvice Lakes National Park. Due to the most intensive mineralization, high pH and supersaturation the chemical composition of water on the Lake Novakovića brod was chosen for comparison of precipitation in nature and in laboratory conditions in artificial karst water. Using a laboratory model of calcium carbonate (CaCO3) precipitation the influence of environmental molecules (humic acid, HA and fulvic acid, FA) and anthropogenic ions (phosphate, PO43− and polyphosphate, (PO3−)n) were investigated. Spontaneous precipitation experiments, in the range 10 ° C < θ < 25 °C, have shown that the added additives change the morphology, polymorph composition and inhibit the formation of vaterite and aragonite: (PO3−)n > (FA ≈ HA) > PO43−. Lower temperatures cause the formation of smaller amounts of CaCO3 and with the addition of the high concentrations of additives, the precipitation of CaCO3 is completely inhibited. Rhombohedral {104} calcite and plate-like {001} calcite were used for crystal growth experiments in artificial karst water. Analysis of kinetic measurements showed that the growth of {104} calcite and {001} calcite crystals in artificial karst water, θ = 20 ° C, occurs on a spiral dislocation and that the growth of {104} calcite is much faster than the growth of {001} calcite. The addition of additives causes inhibition of {104} and {001} calcite growth: (PO3−)n > (FA ≈ HA) > PO43−. The applied additives cause a change in the growth mechanism, which becomes controlled by surface nucleation.

• Keywords: antropogene molekule; krška voda; okolišne molekule; pločasti kalcit; rast kristala; romboedarski kalcit; sedra; spontano taloženje
• Keywords (english): anthropogenic molecules; karst water; environmental molecules; plate-like calcite; crystal growth; rhombohedral calcite; tufa; spontaneous precipitation
• Language: croatian
• URN:NBN: urn:nbn:hr:217:197251
• Promotion: 2021
• Study programme: Title: Doctoral study in chemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 160 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2023-07-14
• Created on: 2021-09-07 12:38:09