...
Overview
After the failure of the second experiment in which distilled water was used, the team decided that calcium carbonates were probably not the source of the problem. It was thought instead that reaction kinetics were the limiting factor and that lime/water contact area needed to increase. The idea for the third experiment was to dramatically increase the volume of the lime in the reactor in order to provide more solid lime surface area. With the same flow rate as was used in experiment two (120 ml/min), 200 grams were added instead of 20, a ten-fold increase. In an effort to determine what the failure mode would be if lime were continually added without cleaning the reactor in between, the team decided to add an additional 200 grams whenever the effluent pH dropped below saturation. Because it seemed to perform better than the original, particularly with large amounts of lime, only the large reactor was used in order to save water.
...