Week of July 11-16 Part Two

Building began Friday, with cutting of the metal. We are still on schedule, and should be done with building by mid-next week. Once the frame is welded together, we will be able to conduct testing as to its effectiveness compared to the flocculator in the lab.

This weekend we planned a trip to go hiking in Zomba, on the mountain. The president has a residence on the mountain, and it was very scenic driving up as many old houses and trees were along the road. Apparently, Zomba used to be the old capital of Malawi and thus has a more historical feel to it compared to Blantyre. Once higher up on the mountain, we saw many people selling raspberries, which was exciting. We ended up filling a one-gallon zip lock bag with them before leaving. Once on the hike, I got very confused all of a sudden, as I started to smell pine trees and see pine needles all over the ground, as if I were back in New England. Our guide told us that these trees were imported and grown for the lumber industry. It was certainly a strange landscape, seeing pine trees in the sub-tropics and raised the question of how common a practice it has become to import foreign trees for logging. Next week, we should be able to finish building our apparatus and maybe even go out for a water collection.

Week of July 11-16 Part One

Now that a design has been decided upon, we put together a shopping list. We wanted to use both easily sourced materials as well as inexpensive ones. We thought scrap metals would be the best material for this and we went to the market. To gather all the materials, both for the framework and for the stirring apparatus, we spent about three afternoons at the market. On Wednesday, we met with Dr. Mkandawire, who said we were on the right track. Despite earlier discouragements that building would be a misguided project, she believed that we should still put forth efforts to devise a treatment system even if it might fail in the field because it would all be part of the learning process.

On Thursday, we had a scheduled trip to the Blantyre Water Board’s collection and treatment facility at Walkers Ferry. We hoped that by visiting the municipal water treatment system, we would have a better understanding of how water treatment works in general and what the standards are for the Southern Region of Malawi. A four-stage process—extraction, sedimentation (several sub-stages), filtration, and finally chlorination—was used to supply over 90% of the required water to Blantyre. A set of pumps, tanks, gages, as well as a large contact tank to store the chlorinated water before being pumped to Blantyre, proved the complexity of water treatment. Our system hopes to combine sedimentation and treatment into one bucket, filtration as a step between the two buckets, and then clean water in the bottom bucket.

Rinse, Repeat… Research

Same old, same new. Right now, it’s just repetition of what I’m familiar with and what I’m still unfamiliar with. I’ve got the hang of running the RO system and using the goniometer to measure contact angles, but I’m still learning how ATRP (remember atom transfer radical polymerization?) works. It’s a lot of chemistry and science at a molecular level because initiators, buffers, attachments of copolymers, etc. are involved. In case you don’t remember from my last report, it is one of the most commonly employed techniques for the development of new materials due to the ability to control molecular weight and polymer structure throughout the process.

We decided to reduce the salinity concentration of the feed water for the RO system because the first modified membrane’s permeability was negatively affected by the polydopamine phase (which acts as the initiator) and therefore it’s flux was low relative to the commercial BW30 membranes. Lowering the salinity allows us to better characterize the surface, especially since the concentration will be at a saturation index of less than one (because at an index of greater than one, crystallization is going to occur regardless of the surface chemistry of the membrane). The concentration at the membrane surface also has to be taken into account because it is always greater than the concentration of the feed. There was a reduced appearance of scaling on the membrane surface after 48 hours in the RO system, but, again, the flux was lower at the same pressures and cross flow as the commercial membranes. Just to give you an idea, the commercial membrane produced a flux of approximately 1.7 mL/min at 350 psi while it took a pressure of about 400 psi to reach the same flux with the modified membrane.

There is a lot of room for error throughout the ATRP procedure, so non-homogeneity is expected, but a lack of uniform coverage of the membrane surface with the copolymers is an issue when it comes to reducing scaling. We were measuring contact angles the other day and the first strip of the newly modified membrane was giving us very low angles with drops of water, which is exactly what we wanted because it indicates that the surface is more hydrophilic. Then, we tried another strip of a membrane from the same modified batch and the angles were almost twice as large. When the membrane was examined more closely, there was a varying level of dullness on the surface, which could be evidence that the modifications are not taking place throughout the entire surface evenly.

This week has been a race against time, with my work ending this Friday and Humberto’s conference taking place a week later. We’re hoping that by performing more ATRP on membranes and having a better handle on the process and consistency of modification, we can gather more agreeable data on the effects of ATRP on scaling. My next post will detail the end of my research here at Yale, and hopefully I’ll have conclusive results by then. Wish me luck!

Last Experiment

As the monsoon season approaches Arizona toward the end of the month, my stay here at ASU begins to end. Conducting three experiments back to back, today I see my last experiments as ASU. All that is left for this set of data is analysis and interpretation. Throughout the week I will be working on a final report and constructing an abstract for future conferences I will attend. This has provided a challenge to be to consolidate everything I have learned in the past month into concise report. Determining the material to add to the report seems like the most difficult task for me to do as well as proper documentation from the several reports and articles I have read.

Several events are being planned this week by both my adviser and roommate. I have my final presentation in ASU this Friday where there is expected to be a larger crowd than normal for my departure. My roommate is planning a get together with some of his friends on Tuesday where I will be cooking fish using one of my Dad’s famous recipes. At the get together everyone will be bringing their own dish to our dorm and have fun. This Wednesday, my mentor, Dr. Bi, and some of my colleagues are going to watch a movie in the istb4 building about space travel and what mankind has accomplished and discovered thus far.

As a conclusion, I look forward to what this week holds for me. In between all of the work and other activities, I am certain I will enjoy my last few days here in Arizona.

Week of July 5-10 Part Two

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.

Week of July 5-10 Part One

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.

Matched Standards

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.


Week of June 26-July 4 Part Two

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.

Week of July 26-July 4 Part One

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.

Queen Elizabeth Central Hospital

Monday in the morning we got t the Poly, looking for Dr. Leautaud. We found her in the design studio, we went outside to talk to her, we explained to he what we had been doing and she decided that this project was not appropriate for us, just like I thought. She explained how we are our own program and should not be involved with outside sources.

We were back to testing how well the moringa seed purifies the water. After we talked to her we scheduled a trip to the Lunzu school site to collect samples and to start testing the seed. We were told we needed to travel with one of our advisors, which were never around. We emailed one of them and he said that he could come with us, just so he would cancel on us five minutes before leaving to the site. For a second time we got shut down. We tried to come up with a project that did not require us going after our advisors so they could travel with us. We remembered that Dr. Leautaud had told us something about testing the water at Queens Elizabeth Central Hospital, which is right next to the Poly. We set up a meeting with the Medical director at the Hospital, we wrote a letter that asked the medical director to please let us test their water, for academic reasons, which Dr. Mkandawire signed. We took this letter to the medical director and she agreed to let us test the water at the hospital. This project seemed great since the hospital is right next to the Polytechnic, and Queens Elizabeth was having some trouble with its water source. We were ready to start sampling their water, we even went to another hospital and scheduled a meeting with their medical director to ask for permission to test their water to compare the quality of the water in both hospitals. First we wanted to get a heads up from Dr. Leautaud. We met with her and got turned down for a third time.