4.0 Results and Discussion
Before the strontium quantification of the solutions resulted from the ion exchange experiments, it was necessary to investigate what is the range where strontium absorbs radiation linearly and what is the detection limit. The graphs below show the absorbance (atomic absorption) in function of the strontium concentration and it can clearly be seen in figure 2 that at concentrations above 10 ppm the samples start to present non-linear absorption. Therefore, all the strontium quantifications were performed working with concentration below 10 ppm and appropriated dilutions were done when it was necessary. The quantification limit was found to be 0.2 ppm and therefore any concentration below this limit cannot be quantified. Figure 2. Absorbance (atomic absorption) in function of strontium concentration.
Before quantifying using atomic absorption, it was also necessary to check if there was any interference that could lead to a wrong reading. It is known that silicon and aluminium can interfere in strontium determination when a air-acetylene flame is being used in the atomization process. …show more content…
The greatest difference is the kinetics of the 25-50 m particles which presented the slowest kinetics in the mordenite experiments rather than an intermediate behaviour just as in NNL and zeoclere experiments. The mordenite 25-50 m particles had a slower kinetics even when it is compared to the 100-150 m particles. After 45 minutes of experiments, the solution analysed from the 25-50 m experiment had strontium concentration of 13.7 ppm while the concentration in the solution resulted from the 100-150 m experiment was 7.8 ppm. The mordenite particles with size below 25 m did not showed a much faster kinetics than the other particles size as it happened with the NNL and zeoclere where the kinetics of the smaller particles were undoubtedly the fastest
Before the strontium quantification of the solutions resulted from the ion exchange experiments, it was necessary to investigate what is the range where strontium absorbs radiation linearly and what is the detection limit. The graphs below show the absorbance (atomic absorption) in function of the strontium concentration and it can clearly be seen in figure 2 that at concentrations above 10 ppm the samples start to present non-linear absorption. Therefore, all the strontium quantifications were performed working with concentration below 10 ppm and appropriated dilutions were done when it was necessary. The quantification limit was found to be 0.2 ppm and therefore any concentration below this limit cannot be quantified. Figure 2. Absorbance (atomic absorption) in function of strontium concentration.
Before quantifying using atomic absorption, it was also necessary to check if there was any interference that could lead to a wrong reading. It is known that silicon and aluminium can interfere in strontium determination when a air-acetylene flame is being used in the atomization process. …show more content…
The greatest difference is the kinetics of the 25-50 m particles which presented the slowest kinetics in the mordenite experiments rather than an intermediate behaviour just as in NNL and zeoclere experiments. The mordenite 25-50 m particles had a slower kinetics even when it is compared to the 100-150 m particles. After 45 minutes of experiments, the solution analysed from the 25-50 m experiment had strontium concentration of 13.7 ppm while the concentration in the solution resulted from the 100-150 m experiment was 7.8 ppm. The mordenite particles with size below 25 m did not showed a much faster kinetics than the other particles size as it happened with the NNL and zeoclere where the kinetics of the smaller particles were undoubtedly the fastest