Jae's Individual Contribution Page

Spring 2011

As the leader of the stock tank mixing team, I was responsible with thinking about different mixing design systems, organizing and leading the experiments in bench scale, and analyzing this information in order to implement these designs to full scale in the current plants in Honduras. We experimented initially with alum and in the middle of the semester changed to PACl. Therefore, we were able to create experimental designs for both coagulants.

Over the first two weeks of the semester, we started with researching about the properties of alum and finding feasible mixing designs to completely mix the system. At first, I did not realize that the mixing process was divided into two steps: dissolution and homogeneous mixing. At that time we solely focused on dissolution. We experimented with filters and considered implementing static mixers to mix the solution and we took occasional trips to Home Depot to buy pipes, fittings, and filters to experiment.

The probably most important difference between alum and PACl in the point of view of stock tank mixing, is their dissolution rate; the alum takes a while to dissolve and therefore we have to design in order to implement dissolution into our experiments. The first two experiments below were done with alum coagulant and we only worried about dissolution.

Our first experiment was the "double bucket" design; the design was originally taken from Surface Water Treatment for Communities in Developing Countries by C. R. Schulz and D. A. Okun (Reflection 1). We also experimented with "moist" alum, which, in this state, is very hard to dissolve. In order to prevent this state of alum, the double bucket design always had the alum submerged. One of the assumptions we was once the alum particle becomes small enough to flow through the filter, it will be considered "dissolved" alum. However, we soon found that the filter gets clogged more consistently than not and we concluded that filters in these experiments were unreliable.

After the "double bucket" experiment, we conducted the upflow experiments, which involved mixing the alum solution through vertical up flow. This gives the advantage of the up flow water being more into contact with the granular alum and dissolution of the alum.

Summer 2010

I helped run some clay experiments and learned how to use the process controller and the lab bench-scale setup. I also helped troubleshoot some mechanical errors in the lab system.

Fall 2010

This semester, I ran some clay experiments and I analyzed the calculations need for the aluminum tube high velocity gradient experiments.