Fall 2008

For the first half of this semester I started out by addressing the flow controller precipitation problem. The first step was to identify the problem. It was determined that the chemical precipitating out was calcium carbonate by familiarizing myself with material written about the problem in other water treatment plants and by talking to the Aguaclara engineers located in Honduras.
Second ideas about how to deal with the problem were brainstormed. Ideas that floated around were designing a calcium hypochlorite feeder that would attempt to settle the calcium carbonate out before it reached the flow controller, changing the pH of the solution so as to inhibit the precipitation at all, and or developing a procedure for operators that run the plants or chlorination systems to perform that would eliminate the precipitant before the solution is introduced to the system.
The idea of altering the pH by adding HCl was a beginning idea, but currently has been pushed to the side because of doubts that Monroe expressed about the feasibility of introducing another chemical to the system. Designing a settling system to add to the chlorine holding tanks was also pushed aside because of its potential expense and doubts pertaining to its effectiveness. I don't believe that a settling systems benefits would have been drastically, if at all greater, than a procedure for settling out the calcium carbonate performed by an operator. Having an operator settle out the calcium carbonate using tools and or devices already in use the facilities will be more cost effective.
Lastly, a new problem with chlorine tube connectors came to my attention. The new polypropylene fittings ordered for the chlorine tanks appear to be leaking. At first they appeared to be the same as the fittings that were used before, just made out of a different material. But when they were put to use it became clear that they must have a slightly different design because the chorine solution begins to leak out when it is added to the holding tank.
Currently, I have reproduced the problem here at Cornell with the same fittings used in Honduras. Next I am going to break the fittings apart and compare them. I will then determine if I can retrofit the current fittings with perhaps more o-rings or recommend that we switch to a different fitting.