Thursday, July 30, 2009

Synopsis of My Learnings and Some Anecdotes

Author: Dipesh Dey


1. How to plan research work well ahead of time before onset of actual experiments, with a publication in sight.

2. How to ripen sand, i.e. grow biofilms on it.

3. How to collect river water and store it in airtight manner best avoiding possibilities of bacterial growth in it.

4. How to use Total Organic Carbon analyzer.

5. How to test ATPs of sand with biofilms on it.

6. How to characterize the dissolved organic carbon (DOC) matrix of water samples, in terms of humic-like, protein-like substances, using Flourescent Excitation/Emission Matrix (FEEM) instrument.

7. How to obtain FEEM spectra without using FEEM instrument, but rather a combination of simple spectrophotometer and a Matlab code.

8. A bit of: How to determine descriptors using analytical softwares like Hyperchem, Chem3D and Dragon.

9. A bit of: QSAR modeling (Quantitative Structure-Activity Relationship) to predict biodegradability of a chemical structure and find removal of pharmaceutically active compounds from water/wastewater without conducting experiments in the lab.

10. How to work in a different atmosphere with different infrastructure-based organizational practices.

11. Why research papers coming out of Holland in peer-reviewed journals have too many authors in 99% cases!

12. A lot more, but nothing official about it.


1. Some Dutch doctoral students like to have Indian snacks with Dutch beer! It reduces their graduation time, they believe.

2. How to take portrait photograph of a stranger Dutch woman on a Dutch street if you can't speak Dutch - be direct in approaching her with your camera lifted to your mouth level, strike an innocent Garfield expression with your eyes, wait a second to let her smile, click; else, please don't ask, let her go, she is really busy!

3. Ripley's Believe It or Not! A Ph.D. student gets a stipend of 5,000 USD/month and a Post-doc 10,000 USD/month, with tuition, medical expenditure and accommodation fully free, in King Abdullah University of Science & Technology (KAUST), Saudi Arabia (where Dr. Gary Amy is the new Director of Dept. of Water Desalination & Reuse)!!!! A Lecturer with a Ph.D. and 1 year of Post-doc experience, serving in UNESCO-IHE Institute for Water Education, Delft, the Netherlands, earns lesser!!! Sun Kyu (Andrew) Maeng adds, "Believe it!"

4. Where would you go for a family weekend outing if you lived in Delft in the Medieval period? There's a house in Delft, known as "the lunatics' house", close to the bottle-neck shaped house. In the 16th century the house used to be the venue of a club of highly intelligent people, who always looked crazy by appearance and never socialized. Common people used to buy tickets to sit in a glass-covered room in the house (the-then laughter room), to view them doing weird things and break into laughter. What's the use of that building now?....Its a students' hostel!!! (learnt from the guide of Delft canal trip.)

5. A Dutch roadsign beside a canal in Koornmarkt, reads, "Niet plassen in het kanaal van water"!!!! Use google translator for the meaning in English! I guess the roadsign glows in a dark night! (showed and translated to me by co-traveler Alcina, a language teacher in a Dutch school).

Tip for new IRES student:
Plan your 2.5 months well....1 month, sleep well, 1 month work very very hard, rest 2 weeks in the end, wonder what Dr. Yeh expected of you!!!

Coming To The End

Author: Hong Ting (Sam) Chiu

Time flies. It has already been ten weeks and my stay in the Netherlands is coming to the end. With less than 30 hours from the flight departure, my feeling here is rather a mix. I want to go home and see my family; yet, I do want to stay in the Netherlands and continue to see this beautiful country.

With such a short stay, I would say I am satisfied with my time being here. I managed to complete what I supposed to. With the guidance and support, I was able to run the batch and column experiments as planned originally. Although the results might not be perfect nor ground breaking, I have developed the ideology and mentality on doing research. From the numerous 12 hours workday I had here, I have learned a lot in terms of knowledge (knowing arsenic more than ever), experience (designing an experiment), and skills (actually setting up and running an experiment on my own). All these are more valuable than the actual data produced.

In addition to the research learning, the real life learning experience is the other things I got out of this trip. I have never been to Europe before; so the Netherlands is definitely something new. I am amazed by the infrastructure, the transportation system (bike paths and sophisticated train system), and the canal (yes, even after seeing so many...). I am really glad that I had the opportunity to learn about the Dutch water defense and the view points on fighting the global climate change (with the attempt to make the city climate proof). All these are something I have never seen in the Florida and Hong Kong (well, may be the public transit in Hong Kong. But still, Europe's is different :D).

The crowd at the UNESCO-IHE is diverse and they have people all over the world (at least more than my fingers). I have managed to meet some new people. It is always interesting to talk to different people and listen to what they have to say. The interaction has widened my horizon on different cultures and beliefs. I have also tried many food that I have never tried before (for some, I still don't know what they are :P. But they were tasty.). However, all the people I met do hold the common goal - they are all here to try to make the world better, greener, and more sustainable.

This trip has been wonderful and really opened my eyes. I would like take this occasion to thanks National Science Foundation to sponsor this program; Dr. Daniel Yeh (USF) for coordinating this trip; Professor Gary Amy (UNESCO-IHE/KAUST), Dr. Branislav Petrusevski (UNESCO-IHE), Dr. Maya Trotz (USF), Ms. Valentine Uwamariya (UNESCO-IHE), and the UNESCO-IHE lab staff for their guidance, support, and the patience to bear with me; the Florida Earth Foundation The Florida-Holland Connection Team for letting us be on part of program. Thank you very much (and time to get back to packing).

Wednesday, July 29, 2009

Tot Ziens

Author: Wendy Mussoline is time to say tot ziens (goodbye in Dutch) to the friends we've made at IHE, the chilly summer days, and the late night sunsets. There are many things I will miss when I return to Florida. The amazing bike paths, the scenic canals throughout the city, the ringing of the church bells in the centrum, the weekly market, the lab staff at IHE, a gas chromatograph with perfect calibration lines, and especially my DUTCH bike. I sold my bike to a very kind student that placed the highest bid on marktplaats. She agreed to buy it two weeks ago, but was willing to let me hold onto it until I was leaving. Thus, today was the first day I had to walk from IHE to the dorm...thank goodness for my Dutch bike!

During my time at IHE, I have gained a much better understanding of anaerobic digestion processes and how different key parameters can provide insight as to what is actually occurring in the reactor. Jan, post-doc student and mentor, gave me confidence to try new things and orchestrate experiments in "real time" process the results from one set of experiments and apply that knowledge directly toward the next set of experiments. There was a set plan, but we always built in enough flexibility so that we could make certain adjustments based on new insights and discoveries. I've learned that plenty of data can be generated, however, success comes through processing, analyzing and discerning which data contributes most to the overall problem statement. I've also learned that making mistakes is part of the just have to learn from them and move forward. I am excited and ready to continue investing in research efforts back at USF.

The atmosphere at IHE was always buzzing with stimulating conversations about culture and perspective. Whether we were having a group conversation with random students during lunch or attending a presentation given by staff and/or students, the focus was always on establishing global partnerships and implementing sustainable techologies in developing countries. Although everyone in the lab was working independently on their own research, there was a communal sense that we were all there to contribute to a unified vision - achieving the millennium development goals. That sense of community really provided the motivation to continue the daily work in the lab. The presence of the lab staff also made a huge difference since they were primarily there for help and support. The work that I accomplished in such a short 10-week period was made possible through the continued support of my mentor as well as the six lab staff. I conclude with a very special word of thanks to my primary mentors during this summer research opportunity - Dr. Daniel Yeh (USF), Dr. Piet Lens (IHE) and Jan Bartacek (IHE). I am certain that the investment that these individuals made in me this summer will strongly influence the direction of my dissertation as well as my life goals.

Sunday, July 26, 2009

Belgium and Beyond

Author: Wendy Mussoline

IHE sponsored a trip to Belgium last weekend and most of us joined along for the fun. We spent two days touring four cities in Belgium - Antwerpe, Brussels, Gent and Brugges. We enjoyed the chocolate in Antwerpe, the nightlife in Brussels (after seeing the Manneken Pis, or little man peeing, and the gigantic iron molecule), the flemish folks songs in Gent and the boat tour in Brugges. It was a great trip with a real Belgium guide who quickly bonded with us after just a couple Belgium beer. You really only need two for the night, since the beers are typically around 9% alcohol.

Belgium was a nice break for me. It was the first time that I spent a weekend travelling and didn't have to think about where I was going. Sometimes I got frustrated trying to follow a group of 58 students, and I had to sneak away for some barefootin in the park. But the group experience was awesome for meeting new people and making new friends. I think Guy (pronounced Gee), our quasi tour guide, will forever be our favorite IHE staff.

After the long weekend in Belgium, we all came back and prepared our big presentations that we gave to IHE/USF (via video conference). Each student presented 15 minutes of background/methods/results of our summer research experience. IHE staff and students were very supportive and celebrated our accomplishments with us. It was a very bonding experience, until we lost SKYPE connection with USF during the last presentation and were unable to reconnect.

Our week also consisted of a wonderful presentation by Bas Heijman and three of his PhD students at TU Delft (the largest technical university in The Netherlands). We heard awesome presentations about drinking water treatment technologies employed throughout the Netherlands and how TUD contributes to ongoing research for the water companies. We heard a couple presentations on membrane filtration and fouling, and how wind-powered reverse osmosis units are being installed in remote areas of the world to provide fresh drinking water. It was an exciting opportunity to learn about technologies that are being designed and implemented as we speak.

The experience is drawing to a close and my feelings are mixed at this moment. The time here has been absolutely enriching and the focus on global issues in developing countries has been life-changing. This environment is a truly a breeding ground for fresh ideas for sustainable technologies related to water and wastewater treatment. However, the academic growth combined with the cultural influences have "flooded" my mind and I do need some time to digest and process the things I've learned here in Delft and beyond. I'm looking forward to going home next week...I really dread the thought of driving to work...wish I could take my bike back on the plane...but if I took it apart, I don't think I could ever put it back together. Oh's already been sold and the new student will pick it up from me two days before we leave. I may shed a tear!

MFI-UF Testing

Author: Michael Gerdjikian

After having various problems with the spectrofluorometer, I took a break to work on the MFI-UF tests. Although the process itself is very simple, it took me a while to understand many of the concepts behind it. In order to run the tests, extra pure MilliQ water is filtered through a membrane at constant flux and the pressure is recorded over a 15 minute interval. This is necessary in order to get the membrane resistance. Then, the sample water (for example RO feed water) is filtered through the membrane at constant flux for 30 minutes and again the pressure is recorded over time. Using this, the MFI-UF is calculated during the time of constant pressure increase over time (time during cake filtration). Since there is a decent amount of time in-between tests, it sometimes got boring. However, I used as much of that time as I could talking to Mamoun and reading through his thesis to get a better understanding of the purpose. It was very helpful to have him at my disposal whenever I was reading something that I didn’t fully understand. He was patient and talked me through it all and now I am able to understand a lot more about the testing than when I first began.

Friday, July 17, 2009

Arsenic Flashbacks

Author: Duncan Peabody

The important people upstairs had some questions about the kinetics curves that we produced with our first experiments. Those were the experiments where we spent 12 hour days holed up in a closet. We found in our original experiments that Calcium levels were much lower in samples with Arsenoic V than in samples with Arsenic III. To get a better understanding of what the calcium is doing I am running some new batch experiments, half with Arsenic and half without. Then we can compare how much Calcium is adsorbed with and without Arsenic. In order to preserve my sanity I have developed a more active set-up for the experiment this time. Rather than bring all of the equipment I need into the small room where my experiment is, I have located different parts of my expriments in different parts of the lab. That way I get to walk around a lot. It's called Excercise Science. For the next experiment I will locate things in different parts of town and jog between the stations. I think this is going to catch on. You may find it ironic that I am doing something not very sane to preserve my sanity. But you're wrong. I'm a scientist.

Yesterday I played in the UNESCO IHE Football (soccer) Tournament. I was an honorary memeber of the Latin American team since there was no team for the United States. We made it to the semi-finals and got 3rd place out of 10 teams. Now my back hurts and I have to contort my body in funny positions to pick things up in the lab. Maybe I'll include it in my excercise science routine.

I broke my bike. The pedal fell off. And when I was trying to fix the pedal I got the brilliant idea to try to fix the back tire as well because it was wobbly. 30 minutes later the tire looked like it had been run over by a car. Now I would be glad to get it back to the condition it was in before, but I don't know how. I suppose I could bring it to a bicycle repair shop but that would be admitting defeat. Instead it will remain on the floor in my room and we'll call it a stalemate.

Thursday, July 16, 2009

Duckweed Destruction

Author: Robert Bair

Sorry dear fans for the absence of news. These last few weeks are going to be hectic as we try to wrap up research and “extracurricular” traveling. Ever since I found more duckweed I’ve been trying to catch up for the lost time. Two weeks ago I was trying to run two full experiments in one week. After putting in some extreme hours I realized that it was impossible to run the two at once. There is simply too much to do! Digesting the plants is what takes up most of my time. I have to wait until they are dry, then mill them, digest them, dilute them and test them. It doesn’t sound like much, but trust me it takes forever! You also have to remember that everything I do is in multiplies of 25

My desorption results are looking good for both lead and zinc. They follow the patterns that we predicted, but the mass balance is still not working out. For lead we are still missing an average of around 30%. Acid rinsing the glassware helped, but not much….

Due to the workload I found myself in the lab one Saturday, it was then that I decided that I needed a break. Right after doing what I needed to in the lab I packed my stuff and started biking. My original destination was Antwerp in Belgium. It was around 60 miles away from delft in one direction. I found the directions online and wrote out my path on a post-it note. I had a map of Belgium, so as long as I was able to get out of the Netherlands I would be ok.. .. so I thought.

About 30 minutes into the trip I got amazingly lost. Nothing on my post-it note made any sense! I pulled out my map of Belgium and tried to look as confused as possible. Luckily the ploy worked and someone came up to me and asked if they could help. When the good Samaritan looked at my map they chuckled just a little. I was at least 40 miles away from where the map even began! After talking for a while they invited me to their house and gave me a map of the Netherlands and a few refreshments for the road! What hospitality!

One bike accident and six hours later, I found myself a nice spot in some bushes and pitched my tent. I never made it to Antwerp. I got lost too often to make it all the way. I did however make it to Essen, Belgium. It is one of the few “Fairtrade” certified cities. Even without reaching my goal I was quite satisfied by what I had accomplished. The following day I made my way back Delft. In all I traveled over 110 miles by bike. Quite a feat considering that my back tire still rubs up against the frame.

Until the next update, Bonjour!

Tuesday, July 14, 2009

Busy With The Columns

Author: Hong Ting (Sam) Chiu

It has been more than 3 weeks since my last post!! Recall that the AAS wasn't working properly and I needed the result in order to move on with the batch. At the end, I decided not to be idle and switched gear to the rapid small scale column test (RSSCT). Since then, I have been pretty busy and working on the RSSCT.

How RSSCT occupied my time? Here it goes...

For the first week of RSSCT, I had to gather and setup all the equipments and chemicals. I have chosen a 100 liter tank for the source water to prevent the lack and the non-uniformity of the source. I have to move the tank up to the bench before filling it up (filling up the tank is often fun to watch; only if the filling tube doesn't fall out the tank and makes a spill...) - because it is too heavy to move after filling. I also put a stirrer and a pH meter inside; but to secure the equipments, I used numerous stands and metal rods, which looks like a sculpture. As the tank is on the bench, I have to climate up the bench to add acid/base to adjust the pH.

RSSCT Setup.

The two columns.

Glass wool.
Some bad stuff.
The glass is still be able to cut my fingers when I have the gloves on.

After the first week, I have to actually run and analyze the samples collected. For the first set, I would like to have a close-to-complete break through, therefore, it was ran for 56 hours duration. The other trials with different parameters are then decided to keep at maximum of 10 hours. Many samples were collected.

I was collecting the effluent samples.

I attempted to run the AAS again and the signals were way less than usual. Therefore, the lab staff decided to change the graphite tube. After that, everything works fine (and it is still okay as of today). So, there is no more un-solvable AAS problem.

But, one problem gone and another faded in. When preparing the source, I used 388 mL of stock As(V) solution. That 100 L tank supposes to last for one more set of column; I need to run at least two more sets. And unfortunately, the lab runs out of As(V) stock solution and the salt went missing. They have to order a new salt and I have no idea when it would be delivered. I guess I will consult the lab staff when I really need that stock solution and hope it would arrive soon.

Friday, July 10, 2009

Only Three Hours to Frankfurt

Author: Wendy Mussoline

You gotta love Europe...wake up Monday AM is Wachenbuchen (a small village near Frankfurt Germany)...hop on the ICE high-speed train and I'm back in Delft in time for work! Amazing! I do love the weekend adventures...I was able to rekindle a friendship with a dear friend that I met in high school when she came to the big town of Palatka (FL) as an exchange student...I spent a couple summers with her several years ago in Germany and met many of her family members, one of which now lives at my parents house in Palatka...I was able to share a toast with he and his new fiancee (Martin and Esther)...and continue to meet new faces and make new friends so the beautiful cycle of foreign exchange can continue to was so refreshing!

My time at IHE is flying by...My days in the lab are so busy that I never realize it is 6:00PM until I run into the janitors...then I realize that everyone (except the USF students) have gone home for the day...I am growing more confident with the lab instruments, methods and procedures that are pertinent to the anaerobic digestion process. I'm able to process the data that we've been generating for the last few weeks and begin to make some sense of it...Seeing the big picture of how it relates to the research that's been done in the past and how it contributes to studies in the future is rewarding. I feel prepared to head back to USF and initiate my dissertation work.

Outside of work and travel, there is of course the routine adventures to the grocery store...I've learned to go often and purchase small portions at a time...thus, I don't have all the groceries spilling all over the sidewalk on my bike ride new rule is only buy what can fit in a small bag strapped to my luggage rack and the sling backpack I carry everywhere. This helps me to blend in with the localsl...otherwise, I look like a clumsy american who thinks that you must have a car to grocery shop...I'm actually trying to figure out how to shed my car in the US and just bike everywhere...the problem is that amtrak would significantly limit my weekend could I get to a gator game in two's not gonna work.

Friday, July 3, 2009

End of the Duckweed Crisis

Enough with the suspense! I know everyone reading this blog was at the edge of their seats with my last posting. I am happy to say that the duckweed crisis has been adverted by quick thinking on behalf of the lab staff.

I was sent to TU Delft's botanical garden to collect more duckweed. The botanical garden was relatively small, but contained a great deal of diversity. In the location where they keep the duckweed they had tiny flightless birds that served to naturally control pests. They look like they would make great pets....

In the end, the botanical garden didn't have enough duckweed to suit my needs. I then just roamed around the city in search of some good duckweed. We visited three different ponds that were completely covered in duckweed. It seems that there are three common types of duckweed in the Netherlands. One species is twice as large as the one I am working with. The other type is about 1/10 of the size. I collected about 4 kilos of mushy duckweed and returned to the lab. Then all I had to do was sieve the duckweed salad through a 10mm screen and get my precious Lemna gibba.

I am now ready to roll!

Wednesday, July 1, 2009

Two Roads Diverged in a Lab....

Author: Duncan Peabody

...and I took the one with adsorption isotherm batch experiments. We're at about the half-way point in terms of research and Sam and I are splitting up the work to try to get more accomplished. Sam is going to continue with the Rapid Small Scale Column Tests (RSSCT), which sound very exciting but I think it's false advertisement. The effluent just drips from the columns. There's nothing rapid about it. I am going to start some more batch experiments to produce Adsorption Isotherms. These are even less rapid than the RSSCT but at least they don't offer false hopes of high velocity science. I would tell you what exactly these isotherms are but I don't fully understand it yet. Hopefully Professor Cunningham isn't reading this because he would be very upset to hear that I've already forgotten how to do isotherms. I'll know again soon.

What I do know is that the isotherms will compare the sorption of Arsenic at various pHs, with and without Calcium, and with two different sorbents. The first sorbent is a commercially available Granular Ferric Hydroxide (GFH). The problem is that GFH is quite expensive for a family in a rural village in Bangladesh where Arsenic concentrations are naturally present at dangerous levels. The second sorbent is Iron-Oxide Coated Sand (IOCS) which is a byproduct of some water treatment plants. Usually the IOCS would just be disposed of but it has been found to be a very good sorbent for Arsenic and other heavy metals. The IOCS can be used in a filter for point-of-use drinking water treatment. The research now is focused on how various water quality parameters will affect the effectiveness of the filter. The particular parameter that we are focusing on is Calcium.

We met with Professor Gary Amy today to go over the results we've produced so far. I was kind of nervous to see his reaction because I wasn't sure if our results were any good. He told us that we had just solved the world's Arsenic crisis and we could go home now. Well not exactly but he also didn't tell us to throw away our results and start over so it's almost the same thing. He gave us some good advice on how to proceed with our new experiments. I think we have a good idea of what we will try to accomplish in our remaining time here. Unfortunately we won't be able to accomplish everything that we had planned on at the outset but we will at least have a solid start on this subject for somebody else pick up in the future. I blame the delays on the AAS which seems to have a personal vendetta against us. Or actually it's just broken but I'm going to take it personally.

Wednesday, June 24, 2009

The Trial at Wageningen and Lots of Fruit!

Author: Wendy Mussoline

I entered the courtroom a bit late because I still don't know north from south yet I continually challenge myself to travel by train and then 6 miles by bike to an unknown destination...with a poor I've just arrived in Wageningen and standing in front of the train station staring at the city map...I clearly know that I have to travel 6 miles SOUTH to my destination...its around 10AM, but the Holland sun just is not really at the 10AM position that I'm used to in I ask a couple standing near the map "Which way is south?" They do not know either and they point me in the opposite direction...I am just mounting my bike, when a local townsperson asks where I'm going..I say to the univerity in Wageningen and he turns me back around and sets me on the right is true...I am directionally challenged but I am determined to perservere through the handicap!
So I attended a trial...well, it was actually a doctoral defense, but it appeared as though it was a trial to me...the defendent was standing center stage with two "wing-men" on his sides (all dressed in tuxedos)...the opponents consisted of a panel of four robed professors on the left that were firing questions left and right...the promoters were quiet in their robes on the right. After exactly an hour, a lady came in with some type of fancy staff (i'm sure it has a name), rang the bell and declared the session was finished...the professors left and then returned in 15 minutes to give the verdict...and the verdict was the Raoul received his doctorate degree from Wageningen University through his research on methane oxidation and sulfate reducing bacteria within an anaerobic reactor that he ran for literally 900 and some odd days. The topic was also very interesting, but the dramatic presentation was even more impressive.
So since I was already in the far Eastern part of Holland, I rode by bike about 20 miles along the Lower Rhine River and into parts of the Utrecht National Forest to arrive at my weekend destination. I visited a Christian ministry house in Eck en Wiel (L'Abri) for the weekend and met about 30 people from US, Holland, South Africa, South Korea, etc. The house is in a rural farm area and students from all over come to visit for a weekend or some come for a "term" which is three months. The goal is to study the Scriptures in the context of a Christian community and participate in the daily chores such as preparing meals, picking berries, painting the house, patching the roof, planting the garden, etc. It was a unique experience that I thoroughly enjoyed.
This geographical area of Holland known as the Betuwe area is famous for their fruit production. The primary orchards in the area consist of cherry, plum, apple and pears. The famous jam factory "De Betuwe" was a draw until they moved production to Breda in 1992. However, I still found plenty of stands selling fresh homemade jam so I was sure to pick up a few jars...and of course, more cherries for the train ride home!

Sunday, June 21, 2009

Duckweed- half duck, half weed

Author: Robert Bair

I have started to develop a love-hate relationship with duckweed. Despite all of its negative characteristics (one of which I went into detail in my last blog: its stickiness)it has started to grow on me (both literally and figuratively).

Last week I started a second set of experiments with lead as my heavy metal. I am happy to say that the whole experiment went by much smoother than the first one. I knew exactly how to set up the experiment and how to time it. This time I didn't find myself desiring more limbs (even thought I would be entertaining to have some more).

A new problem has arisen; One which threatens my whole project! My precious duckweed isn't growing fast enough to compete with algae. After conducting the experiment for lead, I was left with less than 1% of my original duckweed culture. I might have to wait for more than a week to have enough for another experiment.

In an effort to "jump start" my duckweed, I was sent to a waste water treatment plant to collect fresh influent. It was quite the adventure. I was sent to the WWTP with a bunch of buckets and a driver that had no clue why I was going to the WWTP. After roaming around the grounds for a while, I found out that I had to climb about three flights of stairs to the place where I needed to collect the influent. After carrying about 8 buckets filled with influent down the stairs my back felt like meatloaf. I hope the duckweed appreciates all of my hard work.

As a side note, I finished making my tent. Now I can go camping!

Friday, June 19, 2009

Analyzing The Samples...

Author: Hong Ting (Sam) Chiu

We collected 156 samples last week from the batch experiment and were going to analyze them for the arsenic and calcium concentration this week. We have to use Atomic Absorption Spectrometer (AAS) for analysis. There are two AAS at UNESCO-IHE: AAS Flame, and AAS Graphite Furnace. AAS Flame is designed for the mg/L range, which can be used to determine the calcium concentration; AAS Graphite Furnace is designed for the μg/L range, which can be used to determine the arsenic concentration.

For the AAS Flame, I would say it is quite fun and easy to use (and look at when it is on). Before playing with the machine, I have to first create the standard solution for calibration. And since the samples' concentration is higher than the standard, we then diluted the samples before analysis. Lastly, we put in the lamp and turned on the machine and the fuel gas. A flame would light up when everything are on (and I think it is really cool to look at). Then, I just have to insert a tube into the diluted samples and wait; the reading will then appear on the screen afterward. It is easy enough to use :)

AAS Flame.

AAS Flame.
The flame would light up at the gray slit if the power and fuel gas were on.

In contrast, the AAS Graphite Furnace has given us much trouble. We have tried to analyze the arsenic concentration the last few days; but in one way or the other, it fails to give us the results... Some of the problems are: the injection isn't at the center (which resulted in inaccurate reading), the failure at the calibration curve (UNESCO-IHE lab staff prepares the standard solutions), the analysis program shut off for no reason, etc. Also, it takes about 6 hours for one batch of samples, which includes 6 standards and 55 samples. To make the situation worse is that the booking list of this machine is pretty busy. It has already been reserved for the next 7 business days (luckily, we put our name on next Monday too).

AAS Graphite Furnace.

Problem with the calibration curve.
In this trial, the signal for 50 mg/L is almost the same as 40 mg/L.

We have to wait for the result before we can move on with the batch experiment. It is because we will use the same procedures, but with different adsorbent. If the procedures are wrong or if there is a problem with the method, then all the results will be useless. Therefore, I have to ensure this batch produces good result and the procedures are worth repeating. I am thinking of start planning and setting up the rapid small scale column test (RSSCT), which are independent from the batch experiment, next week. Hopefully, the AAS Graphite Furnace will give some accurate results on Monday.

Thursday, June 18, 2009

New Lessons

Author: Michael Gerdjikian

Every week I come into the lab, I do something completely new. My first week I simply ran water samples in the TOC, UV, and Spectrofluorometer. The following week I learned some of the procedures in doing a membrane autopsy. This includes cutting sections of known dimensions from fouled membranes, placing them in several prepared solutions, and sonicating them for a short while. The purpose of this is to characterize the constituents that are removed from the membrane during sonication and dissolved in the solutions. I’ve been using three different types of solutions; plain filtered water (called MilliQ), a basic solution of sodium hydroxide (pH~12), and the same basic solution with the tiny addition of sodium hypochlorite. In general, we expect there to be more removal as we move from the first to last solution. There were six membranes that I needed to characterize so there were a total or eighteen samples that I needed to test. Plus, we decided that I test how well the process works. In order to do this, I would prepare two more solutions and cut two more pieces of membrane for those. I sonicated them just as I did previously with the other samples. Then the next day, I prepared fresh solutions to put those test membranes in and sonicated them again. If the procedure worked properly, nothing should be removed from the membrane during this second sonication. That was all that I got done that Friday because that was also the day that IHE held the Special Symposium on Water/Wastewater Science and Technology for Sustainable Development in which I attended the entire event from 9:30-15:00. The following Monday, I started diluting the supernatant and preparing them for analysis. I was then able to run all of the samples, after filtering, in the spectrofluorometer and UV spectrophotometer while leaving enough of the sample to be sent for LC-OCD testing. After reviewing the results, I came to the conclusion that the process did not work the way we had hoped. The UV spectrophotometer was showing an absorbance from the test samples which shouldn’t have happened. The spectrofluorometer also showed intensity levels greater than the blank sample. This means that everything that could be removed from the membrane was not removed after just one sonication. There were also discrepancies in the trends of the F-EEMs that made me believe that the basic solution may have been contaminated. I decided to try to run some tests to see if I could find where the contamination may have been coming from. I began by simply running samples of MilliQ water under certain circumstances, such as straight from the machine or after being filtered through a syringe. All of the results should show zero intensities but that wasn’t the case. Neither I or Sergio understands why but the original blank shows zero intensity but any sample I run after that shows some level of intensity. After spending many hours testing the water under various conditions, I’m at a loss of what to do. I cannot continue to test the membrane supernatant until I figure out this problem.

On a new note, Sergio started showing me how to test the Modified Fouling Index (MFI-UF) of the different membranes at constant flux. It seems like the tricky part of this is going to be learning how to use the spreadsheets that he uses to gather all of the data. All I know is that I’m looking forward to getting off of the spectrofluorometer for a while to work on this.

Wednesday, June 17, 2009

A Weekend in Maastricht

Author: Wendy Mussoline
Well another weekend adventure proved to be a complete success. Robert, Duncan and I caught an early train to Maastricht to explore the southern tip of Holland where there are said to be real hills. We squeezed our little city bikes on the train next to touring bikes that cost around 2000 euro each. Yes, our bikes have their own little quirks, but that just gives them more personality! Robert has a homemade luggage rack made out of a wire shelf, Duncan's back wheel is completely lopsided and it looked like it was going to fly off as we headed down the hills, and my bike...well it's just perfect...except, the bell rings constantly on bumpy roads and it only has THREE speeds...that makes it really difficult when I'm climbing hills at a 45 degree angle...and yes, we did encounter a few of those!
Anyway, we almost missed our destination because we were not aware that the back half of the train split off from the front half while the train was in motion and the back half went somewhere completely different than the front half. Fortunately, some kind lady mentioned this when I asked when we were suppose to arrive in Maastrict...we quickly deboarded ourselves and our little city bikes and found a spot on the front half of the train...shew...that was close...
Once we arrived, we had to find a map of the city since we had no idea where we were going. We did map out a route to explore the country side east of Maastricht...truly amazing fields full of orchards and even CHERRY trees..yes, we had to stop and pick fresh cherries from the tree limbs hanging over the fence. So sweet and delicious. Then we found some abandoned caves...which are not actually caves but tunnels through rock that were mined for the sandstone to make concrete. But it was as dark as a cave, so we found some candles and did our own was a small tunnel so we didn't get lost...thank goodness. We had actually decided that this would be our camping site if we couldn't find a hostel or bed and breakfast. After touring all day on the bikes, we did finally found a beer cafe/restaurant that had rooms for rent above. Thank you Jesus! We didn't have to freeze in the caves for the night. This was truly a blessing since all 9 places we stopped at before were completely booked...when we arrived, Robert had blown a tire so he was walking his bike. The owner quickly took us under his wing, poured us big beers and gave us the special of the day...1/2 roasted chicken, pomme frits, and was the best meal I've ever eaten!
As Duncan mentioned in his blog, we took part in the local festival that had very unique traditions. On Sunday, we kept trying to find castles (shown on the map, but they kept alluding us)...Finally made it back into the City of Maastricht...We toured the real system of tunnels that covers over 80 KM...the tunnels were like walking through huge caves with walls over 30 feet high...passageways leading in all different directions...pitch black when the lanterns were turned off..the tour was an hour and we just saw a small part of the tunnel system. Our tour guide said the earliest inscriptions in the walls date back to the 1500's. During WWII the tunnels were used for protection/hiding for the people of the area...about 3000 people in all lived in the tunnels. They had ovens with a big chimney that went up 40 meters to the ground surface. They even stored their precious artwork (i.e. Rembrandt's Nightwatch) in the tunnels during the war. It was a really cool place, literally...temps were 50 deg F in the tunnels...
The architecture in Maastrict was different than the rest of what I've seen in Holland...lots of roman architecture with castles, old forts and a really neat bridge with arches over the river. I think I liked the city the most because a river ran through it...cities with rivers always steal my heart, but none compare to my home in East Palatka (FL) on the St. Johns River.
There was an error in this gadget