Date of Graduation

5-2014

Document Type

Thesis

Degree Name

Bachelor of Science in Chemical Engineering

Degree Level

Undergraduate

Department

Chemical Engineering

Advisor

Hestekin, Christa

Abstract

At the beginning of this project, I elected to focus mainly on the electrolysis portion. I completed a lot of research on electrolysis in general, and then specifically on brine electrolysis, which is transforming a salt water solution into a sodium hypochlorite solution, or bleach. I researched all of the different types of electrode materials and purchased several electrodes in order to perform experiments. I researched several methods of electrolysis in use today. I performed several calculations about the electrolysis reaction, including the electric potential required to drive the reaction (approximately 1.0 volt), as well as what concentration of salt to use for the water and the expected final concentration of the bleach solution that would be created. Based on sources given to us in the Phase I proposal, a salt concentration of 3% by weight was chosen, and this translates to a 0.513M solution. Due to the stoichiometry, this indicates that the highest concentration of sodium hypochlorite solution that was possible was also a 0.513M solution. Based on the electric potential, I ranked what I thought would be the best pairings of electrodes, and I planned how to carry out the experiment. The “best” theoretical pairing of electrodes was the copper and aluminum pairing, because the potential difference between the two metals was the highest, at 2.01 volts. After that failed, I purchased new electrodes with special coatings that were already in use for this type of application and carried out experiments with these electrodes. I performed every electrolysis experiment, recorded data, and drew conclusions about the data I recorded. I determined what the optimal time to run electrolysis was based on the batch size we selected. I took the graphs depicting the data from the treadle pump, sand filter, battery charging, and electrolysis experiments, edited them, and inserted them into the final paper. Although many group members assisted in writing the paper, I went through it and meticulously edited it for both content and grammar. I also filmed the footage we needed for the instructional videos. I assisted with the overall design of the water purification system, including what materials to use, what the size of batches should be, and how we would keep the water clean in the final reservoir. I spoke with a Civil Engineering professor regarding how clean the water must be to kill the microbes we expected to be present in the non-potable water, and we decided to use a chlorine residual of 1-5ppm based on her recommendation. I also spoke with two Chemical Engineering professors to learn more about the electrochemistry of the electrolysis reaction and to consult when I was having problems with the experimentation. I assisted in doing research in other areas of the project, including discrediting the idea of using a scotch yoke, and coming up with an alternative plan. I investigated the use of an alternator to charge the 12 volt battery using a bicycle, and when that failed, I researched about using the DC motor from a scooter to charge the battery using a bicycle.

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