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The team used the same procedure described on the materials and methods . It is important to note that page. The lime was added as dry powder.
According to the calculations based on lime solubility constant; this experiment required 20g of lime and is projected to last for 12 hours, the maximum or theoretical pH will be 12.6, with a For the flow rate of 120mL120 ml/min.
Results
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, it was calculated that 20g of lime were required for the effluent to be saturated for 12 hours.
Results
The following graph shows effluent pH over time. A1 represents the small reactor and A2 represents the larger one. We can see that none of the runs were anywhere close to reaching the goal of twelve hours with a saturated effluent. Both the tap water and distilled water runs with the large apparatus failed within an hour and a half, while the run with the small apparatus never produced any saturated effluent. There is certainly no performance improvement running the reactor with distilled water.
The following graph shows the fraction of saturated hydroxide concentration versus the fraction of time the run is theoretically calculated to last. This is simply a clearer way to display the reactor's performance over the course of the experiment relative to our goal, which would be to have a straight line at an OH fraction of one. In this case, the chart illustrates what are likely measurement errors: a hydroxide concentration nearly double the saturation value in one run and a failure to reach saturation in what should be an identical trial.
Discussion
The similarity in
Discussion
Improvements in the design have worked very well; it is possible to detect an increase in retention time, a decrease in capture velocity and a well mixing in the bottom of the A2 apparatus. With a high flow rate, A1 shows a well mixing in the bottom but capture velocity is very high and it is possible that lime particles escape through the effluent.
The similarity in the performance between the A2 apparatus run with tap water and the A2 apparatus run with distilled water indicates that carbonates calcium carbonate precipitate may not be an the main issue. Failure with distilled water indicates suggests that there must be another issue - perhaps a kinetics issue relating to the dissolution of lime particles. This will require further research with a fluidized bed. See the hypotheses page for further information.