Welcome to the official blog of the NEWT REU internship program, where students from Rice, Arizona State University, University of Texas El Paso, and Yale, will share their experiences and stories from their summer internship sessions. Students will be working on water-related projects with mentors in university labs throughout the United States and in the University of Malawi Polytechnic in Blantyre, Malawi. Click here to learn more about the NEWT Center and here to learn more about the NEWT Program’s education activities.
A major part of the fun I have had is due to fellow REU students. Me and 3 other REU students went up to Sedona for July 4th week. We had a great time hiking, swimming, eating, and just hanging out. Being in Sedona was like being in another world. The energy there was so different. Everyone there had a common goal; explore and have a good time. I only met energetic and friendly people while I was there. That and the beautiful scenery made the trip amazing. The highlight had to be the sunset hike. I don’t have the pictures of it bc my battery was completely gone, but it was beautiful.
For July 4th, me and REU students also went to see fireworks. It was fun walking to Tempe Town lake, and seeing everyone fired up. July 4th in Tempe is like none other. Considering how many people typically leave Tempe in the summer, the streets were still full, and so was the sky.
The first batch of graphene oxide(GO) is complete, the lyophilization was a success. The first batch that has been completed used the Hoffman synthesis method. Close behind is the Staudenmaier method. Based on appearance the Hoffman samples look fine. However, we will not have a concrete analysis of the material until further characterization is done. First, is SEM. This will give us a size distribution of the GO sheets.
Apart from producing and characterizing GO, I have also done analysis on silver coated cellulose membrane. Measuring the surface charge and contact angles for varying silver concentration. I obtained data for 1mM and 6mM Ag coated cellulose membranes. Unfortunately, I accidentally damaged the 3 mM Ag coated cellulose membranes which rendered erratic results.
Next is running SEM for Hoffman GO, then lyophilizing the Staudenmaier GO.
Clog and Owen have designed a two-bucket system for our treatment system. The untreated water will be put in the top bucket with the moringa powder, mixed using a handle secured with a ball bearing, and then left to treat for five hours. There will be a tap at the base of this bucket, and to filter out the moringa powder, the water will flow out and into the next bucket. This bucket will have a chitenje fabric filter, similar to the sari cloth used in India, as it is an inexpensive way to filter out the flocs in the water. Once filtered, users can draw water from the bucket using a tap located at the bottom. Our goal is to create a system as low cost as possible that still proves effective. Coagulation with the moringa seed requires mixing and filtration (or lengthy sedimentation) to work, so we must include such steps in our apparatus, despite making it more cumbersome.
Purchasing of materials will begin early next week so we can start building the system. With an initial set-up, we can workshop a bit to see if we can simplify the mixing and filtering any, as the eventual goal would be to use these in villages on daily basis. If they prove too cumbersome, or simply a hassle, they likely will not be used at all. Making sure that they are actually useful will be a major working point for us in the coming weeks.
During the weekend, some of the group went to the Satemwa Tea and Coffee Plantation to explore the fields as well as go for high tea at the Huntington House. It was nice to be able to explore the estate so freely, walking around the forest as well as the coffee plants. It was a bit rainy, which made the driving and walking on dirt roads a bit difficult, but no less fun.
This week will be a fairly light week, as Monday was July 4 and we were returning from Lake Malawi. Wednesday was the independence holiday for Malawi. We spent the week working through our data, correcting the scaling so all treatment times could be compared because some had to be tested on different dates given the limitations on lab equipment and availability of the microbiology lab that had the incubator. We chose to base our decision on how effectively the moringa seed was able to reduce turbidity as well as E. coli coliform count, as non-fecal coliforms are much less hazardous.
Moringa seed introduced as a powder, not premixed as a solution, proved the most effective method of dosing. A treatment time of five hours and 50mg/L dosing had the best results overall, reducing the E. coli coliform count 100% and turbidity nearly 32%. The effectiveness in reducing biological contaminants was a bit surprising and was the relatively low reduction in turbidity as compared to previous research. It seems that much of the initial turbidity in the water was reduced by simple settling over the course of five hours as the turbidity of the control at five hours was also lower than the initial levels.
Owen and Clog, as mechanical and civil engineers, took lead on the design portion of this project. We believed that despite the convenience of a rolling apparatus, where the rolling movement would serve as ample mixing for the moringa seed powder and water, it would be difficult to use in the villages where there are not smooth paths and the terrain is quite hilly. Additionally, few villagers seem to travel far for their water collection, so we think that an apparatus that can be placed in the home or near the well would be the easiest to use.
This past week was a hard week. Frustration is a thing that all scientist must learn to cope with, and this week I had a taste of it. The experiments we performed, did not showed the expected results, therefore they had to be repeated many times. Dealing with not having the expected results, thinking of ways to fix it, and trying to stay motivated, was not easy. This was my hardest week until now. Nevertheless, not everything was lost, because we were able to get good images from the microscope, of the phage conjugated with the materials. The plans now, are to start the writing portion of my project and bring together all the results from the previous experiments, and the new experiments.
My head is spinning, two weeks left and i’m using every hour to my advantage.
Bright side, our mechanical skid is finally fully functioning!!! Last week we finished the fabrication of the skid and attached all the equipment on. The skid looks amazing so far my pride in my time being here. However, there was one thing that is giving us troubles and that is the module itself. The module is the heart of the skid, its where the water is distilled and it starting to crack under pressure, LITERALLY! We are having a hard time fixing the problem because we don’t now where the pressure is coming from, it should be a zero pressure system. The window is bulging out a bit so that means there is quite a bit of pressure that is building up. Right now our main goal is to fix the crack and hole from which it is leaking. We will then assess the problem by taking one of the temperature sensors out to leave a small hole where the pressure can alleviate itself. We are using epoxy to give it a sturdy fix and is expected to dry hopefully tomorrow. If everything goes well then we can hopefully get a week in of real time testing before I have to go.
As for my computational model, it is going good. I have been running data left and right. The use of the numbers have already proven that when the feed side of the module has a high flow rate as well as a high temperature we will produce more flux. It has also been able to show that the use of Nanoparticles (aka carbon particles) are beneficial to the module to the system as well because it also produces higher flux. The goal right know is to run data that test different channel length in which the water flows to see which is more efficient. Based on what produces the best flux, those measurements will go into making a newer and better module for the future.
Two weeks left, we got this!!!
We were a bit stuck last week in terms of finding a suitable current collector to use with our electrodes, so we reached out to Dr. Tom Davis, who we knew had extensive experience with electrodialysis systems and could most likely provide a few helpful tips. From our research, we knew that a titanium plate would serve as the best current collector, but faced the challenged of finding one that met our stack dimensions and could be delivered in a reasonable time frame. With Dr. Davis’s help, we stumbled upon an El Paso metal company that had a single titanium plate just big enough to be cut to fit our stack. Just needing a way to connect the power supply to the current collector, we went to several places looking for titanium screws to avoid unnecessary corrosion between the metals, but they’re apparently pretty uncommon. Fortunately, we found a company in Nevada that could deliver the screws by Wednesday of this week, so once those arrive all that’s left is to weld the screws to the plates and then we can start testing the system. Cheers to progress
After running several experiments and analyzing large amounts of data I was able to replicate a photocatalyst experiment sent to several labs around the United States. This states that a standard set by NIST is repeatable for observing NADH fluorescence degradation by TiO2 with a phosphate buffer. This has been one of the major tasks I have been assigned to complete for the past few weeks using SRM 1898. Looking towards the future I will be analyzing other TiO2 grades and observing what their reaction rate constants are at different TiO2 concentrations.
Aside from analyzing data, For the fourth of July weekend I went with my mentors to watch fireworks. We brought a few games, and although I didn’t win any, I still had a lot of fun. I also went hiking at Clear Creek Trail in Camp Verde. This was the first time I saw water flowing in nature as well as forests in Arizona and was really excited. I went on the trip with a young professionals, less than 35 years of age, group in environmental engineering. After hiking 8 miles, we went to a well known restaurant and ordered pie, then went to a different restaurant and ordered lunch. This entire weekend was very fun and tiring. For this upcoming week, I plan on seeing a movie and and seeing more of my friends before I leave next week.
Early Saturday morning, we left for a group trip to Lake Malawi’s Cape Maclear. We planned a July 4 weekend with everyone in the program, finding lodging at a very nice part of the lake. The first night there, we experienced a bit of a fiasco, as we planned a boating trip with a tour guide that was not part of the “Lake Malawi Association of Tour Guides.” We were approached by a large crowd of people on the beach, angry that we did not know to book a tour with association. After threatening to sue us and meeting with the head councilman, we were able to smooth everything over and secure a boat to an island for the next day.
The trip the island was lots of fun and there was snorkeling as well as watching the eagles feed on fish. Later that evening we had a bonfire with music on the beach, but there were many group disagreements on how to plan all of these things, which made the weekend also a bit tense. We all had a quiet day on July 4 and headed home later that evening.
Monday night was one of our colleague’s (from the Polytechnic) After delays in the project, we seem to have finally gotten off the ground, and we met early Tuesday morning to go to the Bangwe township’s Ntopwa village with the Dean of Engineering at the Polytechnic University. When there, we were able to visit three different sites of water collection. The first was a traditional looking well, lined with brick, covered, about four meters deep. This was at a specific house and seemed to be the least turbid water. The second was a dug shallow well in the ground, less than a meter deep. This water was extremely turbid, meaning the moringa seed had good potential to improve the quality. The third site was also a dug shallow well, but about 1-2 meters deep and of less turbidity. After collection, we ran tests for pH, conductivity, turbidity, and biological tests as well (to determine both the presence of coliforms/e. coli as well quantitative information).
Ideally, a water source that has high turbidity as well as E. coli count would be the best source to use for moringa seed testing, as it is supposed to greatly reduce turbidity and biological contaminants. The second well was chosen for this reason. It was the most turbid and had large enough quantities of E. coli and non-fecal coliforms that the effectiveness of moringa seed could be tested.
The moringa seed would be tested in different dosages (50mg/L, 100mg/L, and 250mg/L), as a powder, as a pre-mixed solution, and for different lengths of time (1hr, 2hr, 5hr, and 10hr). The 2hr and 5hr tests would be run on Wednesday, while the 1hr and 10hr tests would be run on Thursday. Ideally, all would be done on the same day, but with limited equipment and the amount of time involved, we knew we would have to split the tests across two days, adjusting with separate control values.
I was unable to attend the collections and testing both days because of sickness, but Isabel took charge of the lab work. Once all the results are in (12:30am Friday night), the best dosage, type of dosage, and amount of time can be determined.