https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:16839 (g) to CO₂_(aq) could not keep up with the consumption of CO₂_(aq), resulting in an initial disequilibrium with experimental pH reaching equilibrium quickly, while fluoride removal lagged. Increasing stirring rate significantly decreased the extent of disequilibrium and the time at which the CaCO₃ -fluoride-CO₂ system attained equilibrium due to the increased rate of transport of dissolved CO₂ to the CaCO₃ surface, and simultaneously the rate of transport of the dissolved CaCO₃ to the bulk solution. Optimal fluoride removal occurs at pCO₂ ~10-0.52 [30% (mol% CO₂)] with 96% of the initial 2,000 mg/L fluoride load removed in less than 80 min with a stirring rate of 300 revolutions per minute. Increasing pCO₂ to ~100 (100% CO₂) resulted in very little gain, less than 2%, in fluoride removal, or in the time required to reach equilibrium and therefore significant remediation cost savings can be obtained by using pCO₂ 30% when compared to 100%.]]> Sat 24 Mar 2018 07:53:28 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:22725 Hill 4 > PSO due to the ability of the Hill models to accommodate sigmoidal kinetics. Removal of fluoride from SPLL under atmospheric CO2 conditions was found to be inhibited with no removal occurring for the first 3000 min with the inhibition times, based on the reaction half-life, reducing with increased CO₂ partial pressure and stirring rate. X-ray diffraction (XRD) analysis revealed that the residual solid filtrate consisted of trona (Na₃(CO₃)(HCO₃)·2H₂O) a potentially valuable mineral kogarkoite (Na₃SO₄F) and fluorite (CaF₂) accounting for fluoride removal, and unreacted calcite (CaCO₃).]]> Sat 24 Mar 2018 07:15:27 AEDT ]]>