B.S., Enivronmental Engineering, 2012
M.S., Environmental Engineering, 2013
My name is Kristen and I am a senior at Lehigh, pursuing a dual degree in environmental engineering and chemical engineering. Research has always interested me. In fact, I hope to one day get a Ph.D., become a professor, and eventually be able to fully conduct my own research.
The research I am doing this summer involves evaluating loaded resin as a reducing agent. This can be used for redox reactions in order to reduce a contaminant into a less hazardous form.
Today was essentially an introduction to my research. I met with my professor in the morning and reviewed some concepts relating to my research. Then, I was paired up with a Ph.D. student to guide me through the research process. The Ph.D. student introduced me to the lab and walked me through the beginning steps of preparing ion exchange resins for my particular experiment.
Today I learned just how long it takes to even prepare for an experiment. In this experiment, three different concentrations of resins must be prepared for two different ion exchange resin materials (making a total of six). I will refer to the two resin materials used as Resin 1 and Resin 2 to differentiate. Also, I will specify the concentrations as Cycle 1, 2, and 3. Theoretically, Cycle 1 has the lowest concentration while Cycle 3 has the highest. I can prepare only one cycle at a time for each ion exchange resin material. The Ph.D. student talked me through the last steps of preparing the ion exchange resins. Due to all of the long hours it takes to shake the material and dry it, I did not even finish preparing Cycle 1 of the two resins.
Today I finally finished preparing the first two resins and began to prepare the second cycle of resins with increased concentration. As the second cycle of resins was shaking, the Ph.D. student helped me prepare the column for ion exchange with Cycle 1 of Resin 1. We ran water through the column and I checked levels every two hours. After taking the third reading six hours later, the Ph.D. student pointed out that the levels did not seem accurate, so the column had to be regenerated. Today I learned that research requires flexibility, dedication, and persistence.
I regenerated the column today as the second cycle resins dried. After regeneration, I ran the experiment again for 10½ hours, only to find out that it did not work yet again.
I completed the second cycle resins with increased concentration today. With Cycle 2 of Resin 2, I prepared the column to repeat the experiment, except this time I reversed the direction of the flow in hopes it would improve the results. I ran this trial for about five hours. Once again, the experiment failed.
Today I regenerated the column with the second cycle of Resin 2. Meanwhile, I began preparing the third cycle resins. After regeneration, I repeated the experiment using the reversed flow. I plan to have this trial run for about 24 hours.
After running the column for 24 hours, the results seem to be kind of accurate. Unfortunately, the results are deceiving because the reducing agent used to regenerate most likely produced the desired results instead of redox reactions of the resin. In order to avoid this, I regenerated the resin outside of the column this time, rather than running the reducing agent through the column. After regeneration, I ran the experiment for seven hours. The experiment failed again, despite the new regeneration technique. After several trials and constantly modifying the technique, it has become frustrating to fail again.
Today, I finished up the third cycle resins. I plan to start next week using the increased concentration of the third cycle to see if it affects the results.
I ran the third cycle of Resin 1 in the column until midnight. Unfortunately, the results were not successful.
Due to yesterday’s unsuccessful results on the third cycle resin column, I regenerated the column today. After about two hours of regeneration, I re-ran the experiment for about a day. For the first time the experiment seemed to work! This is so inspiring to me. I am excited to re-run the experiment tomorrow to verify the results.
Today I regenerated the column and ran it again. Once again, the results seemed to be good! Although the third cycle of Resin 1 seems to be successful, I am curious to see if the results improve with the third cycle of Resin 2.
Today I began the process of analyzing the content of the resins. I shook the resins in a solution for the day.
When I stopped shaking the resins today, I realized that all six samples had spilled in the shaker. I repeated the process of analyzing the contents of the resin. This time I added water to the samples as an oxidizing agent. Then I mixed a solution into the samples and shook them in the solution again.
Meanwhile, I regenerated the third cycle of Resin 1 to double-check the seemingly successful results from before. After about two hours of regeneration, I ran the experiment for 10 hours. Fortunately, the results confirmed last Wednesday’s results.
Today I tested the third cycle of Resin 2. I ran it for about four hours but then stopped it because it did not seem to work well.
Today I used the AA (Atomic Absorption Spectrophotometer) equipment to analyze the prepared resin samples for content. Generally, a higher content was found on Resin 1.
After analyzing the content, I regenerated the third cycle of Resin 2. Afterwards, I ran the column for around 18 hours. The results significantly improved, which allows for inconsistency in the data. Because of this, I plan to regenerate this resin again.
I stopped doing experiments for now since we are preparing for moving from Fritz Lab to the new Steps building. I devoted the entire day to cleaning out the old Fritz Lab. It was a long, tedious day.
The movers came today to begin to transport our boxes of lab materials from Fritz to STEPS. It was a fairly short day – basically, we watched the movers pack.
Today we waited for the movers to move the remaining materials. They failed to show up, so all the researchers went home early.
Finally—all our materials have made their way to STEPS. Therefore the entire day was dedicated to unpacking and organizing the new lab. It was a long day, constantly unpacking and deciding how best to organize our new space.
Today we set up a few remaining materials. Then I gathered all of my materials for my experiment—or at least tried to. Finding them was difficult with everything so disorganized. By the time I retrieved everything necessary, it was nearly time to leave and not worth starting at that point.
Today I started to run my column again. I ran the column of third cycle, Resin 2, for the third time. The problem is that STEPS closes early today, so I feel that I do not have the time to fully develop my results.
Today I regenerated the third cycle of Resin 2 again and then ran the column for a fourth time to check consistency. Again, due to the short period of time that STEPS is open, the results cannot fully develop; however, it looks like Resin 1 is more effective.
Today was not an intense day—a bit tedious, though. I typed up a list of all of the chemicals in each cabinet so they are easier to find and so we know what we have in the lab.
Today I started to evaluate the effectiveness of the loaded resin as a reducing agent. I did this by plotting the data and performing simple integrations.
I finished the integrations today and plan on comparing these values to the content of the resin to yield percent effectiveness.
Today I mixed the resins with sodium hydroxide in order to observe the changes in the resin. I am allowing them to shake overnight.
On Wednesday I am supposed to give a presentation about my progress to all the other researchers. Therefore I dedicated most of the day to preparing my PowerPoint.
I presented at 3:30 p.m. today after fixed up my presentation beforehand. My professor questioned everything I included in the presentation. At first that was a bit intimidating, but it made me really think about what I am doing for research. His questions helped expand my mind.
After performing calculations in preparation for the presentation yesterday I realized that the content of the resins need to be reanalyzed to make sure that all contents were accounted for. Today I dried out the previously analyzed resin so it can be reanalyzed in a few days.
Today I weighed out the dried resins so they can be reanalyzed using the AA for content. I tried finding the ammonium hydroxide, which needs to be added; however, it seems to have gone missing in the move from Fritz to STEPS. In the meantime, I started reading Environmental Separation of Heavy Metals, a book written by my research professor. I read it very thoroughly since it applies to exactly what I am doing. I plan on writing an outline tomorrow.
I wrote an outline of the reading today and even did a little extra research online to solidify my understanding. My professor asked me to pick another resin to use that I think would work well for the experiment. In order to do this, I did some research of my own online. I still am not sure of what resin I should use after the research I did today. Understanding resin is so complex that I find it intimidating to be responsible for picking one. I feel like I need an entire class on the chemistry and behavior of resins; even so, I still need to find a resin that will work and that I can justify to my professor.
Today was a fairly relaxed day. I finished a chemical inventory, gathered some extra materials in Fritz, and organized myself.
I added ammonium hydroxide to all six resins to analyze their content. I allowed them to shake for 24 hours. As the resins were shaking, I researched a third resin that could be used.
Today I printed a bunch of articles and started to read about why Resin 1 and Resin 2 were picked for this experiment. This information could help me pick Resin 3.
I continued reading articles today in search of Resin 3. I also outlined what I read in order to make some connections between Resins 1 and 2 and to identify what I should look for in Resin 3. I found it challenging and tedious to read these articles because I do not yet have enough background knowledge of resins and how they work to make an informed judgment.
I finished reading some articles today and then concluded the day by doing some dilutions. These dilutions will allow the instrument I use to determine the content of the resins and be able to take a measurement within its range.
After analyzing the content of the dilutions I did yesterday, I realized that the results did not make sense. I therefore decided to redo the entire process to get more accurate results. I started by shaking the resin in water for around 24 hours.
Today I decanted the water from the resins and added an ammonium hydroxide solution to each sample and allowed them to shake. I later removed them from the shaker and put them aside to be analyzed at a later date. I am going away for a family vacation starting tomorrow, and I thought this would be a nice place to put my experiment on hold.
I came back from my family vacation yesterday. Because I missed an entire week of research I have to work hard now. I started by deciding what to use for Resin 3. Additionally, I realized that when I redid the process to analyze the content of the resin, I did not expose the water to air as it was shaking. This skewed the entire process and results both times because it was not allowing the resin to oxidize. No wonder I got the results I did! I started the process over, but this third time I put the samples on a platform shaker with water and open to the air to allow for oxidation. I also plan on loading the resins with a new technique that may be more effective and quantitative. When I initially loaded the resins I used a batch process. Instead, I plan on using the column as a plug-flow reactor and will load the resin that way.
After speaking with my professor, we decided that exposing carbon tetrachloride to the resins may be a good way to determine their effectiveness as a reducing agent. When we ran water through the column, it was possible that oxygen was exchanging with a functional group on the resin and not actually performing the redox reaction, which skewed the results. Carbon tetrachloride would both solve this problem and confirm the effectiveness of the resins as reducing agents. To do this I started loading Resin 1 using the column. I ran water through the column to rinse the resin today. As that was running I removed the samples from the platform shaker, decanted them, added ammonium hydroxide, and allowed them to shake in the shaker. I also made a 10% solution to run through the column after it was finished rinsing.
I realized that the 10% solution I made was not anhydrous. Consequently, I screwed up the molecular weight, which resulted in a 6.4% solution. I did a bunch of calculations to make a 10% solution with the small amount of concentrate that was left. Later, I talked to my professor, who reminded me that there is no official procedure for this experiment. A 10% solution is not necessary and 6.4% would have been just fine. He also gave me some ideas and direction as to where to go from here with my experiment.
I removed the resin from the shaker with ammonium hydroxide and diluted each sample. Then I rinsed the resins and added water to each. I again allowed the samples to shake open to the atmosphere to determine the content of the resin for the second time. This would allow me to see if anything was left on the resin even after the first process.
Today I decanted the samples that were shaking with water and added ammonium hydroxide to each. Then I allowed those to shake. I also ran the 10% solution through the column to load the resin. I took samples every 50 milliliters (mL) in order to be able to determine the content of each one. This allows me to see the progression of how the resin was loaded.
Today I diluted all of the samples loaded with the 10% solution. I used a dilution factor of 25.
I removed the samples with ammonium hydroxide from the shaker and diluted all of them. I plan on using the AA tomorrow to analyze the contents.
Today I used the AA to determine the content of the resin samples previously mixed with water and ammonium. Since the samples that went through the process twice still showed significant results, I need to repeat the process a third time to double-check that all the contents are accounted for. I also used the AA to analyze the samples taken from running the 10% solution through the column. The AA could not measure the content of these samples because they are too concentrated. Therefore I must further dilute these samples.
I further diluted all the samples using a dilution factor of 100. I used the AA to analyze these samples and it still could not measure it. This means I now have to dilute the samples even more.
Today I made 600 mL of reducing agent to feed through the column. I let this run and could see the color change in the resin. When all 600 mL ran through the column I noticed that not all the resin had changed colors. So I made more reducing agent and ran it through the column.
After running the reducing agent through the column, I removed some of the resin from it to serve as the first cycle of Resin 1. I rinsed the resin remaining in the column by flowing water through it. Meanwhile, I made a liter of 10% solution. I had to heat the solution to dissolve it all. This means that the solution is supersaturated. After everything dissolved, I put the solution aside so I can run it through the column tomorrow.
Today I ran the 10% solution through the column for a second time. I do not know what the difference was between running the solution through for the first cycle and this time, but the plug kept on popping out of the pump. I had to stop the pump and fix it. I also had to get kinks out of the tubing to keep pressure from building up. It kept on happening until I finally realized that there was white, thick stuff forming in the column. A precipitate had formed and was clogging the column. I used a pipette to remove it and started the column again. After a while I noticed the solution was crystallizing. This is because it is a supersaturated solution. I had a talk with my professor, who said that a 10% solution is far too high. The AA cannot read the contents of the effluent because it’s too concentrated and at that concentration, the resin is not effectively loaded. After this conversation I stopped my column. I cannot believe I did not think of this before. I am so frustrated that I just wasted so much time.
Today I made a 0.01% solution instead of 10%. I cleaned out the column and set it up again. Then I rinsed the resin by running water through the column.
Although today was my last day working, clearly I am not finished with my research. I plan to continue this work throughout the school year. After doing an entire summer of research, I realized how difficult it is. Sometimes I got overwhelmed because most of the time things did not work out. I look back at this summer almost feeling like I hardly did anything, just because the project is so big. It is all part of the process though. It’s slow going, but every fail is a step towards success.