Wednesday, June 24, 2009
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 map...so 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 Florida...so 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 course...it 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
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
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 :)
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
Wednesday, June 17, 2009
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 exploring...it 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 salat...it 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 caves...an 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.
Tuesday, June 16, 2009
We finished our week of 12 hour days in the lab last week and we have been trying to analyze our results ever since. So far we have had no success. For one thing the sign-up list for the Atomic Absorption Spectrometer (AAS) is like the reservations book for a fancy restaurant in New York City. (I think. I've never actually tried to make reservations at a fancy restaurant in New York City.) We have managed to sneak our way onto the list twice and have had complications both times that have prevented us from obtaining useable results. But it's all part of the learning experience. At least that's what I tell myself. Hopefully we will be able to analyze all of our samples by the end of the week so that we can begin the next round of experiments. If for some reason our results are not satisfactory I will be forced to conclude that the science is flawed, not our experimental methods. Denial is much easier than another 48 hours spent adjusting pH in a tiny room.
Luckily we have found a way to keep ourselves busy while waiting for the AAS: Table Tennis. We discovered a Table Tennis room on the third floor (4th floor to us Americans) and we have been honing our skills over the past few days. Not to worry, it hasn't affected our work in the lab. If anything it has improved our hand-eye coordination, making us more effective laboratory scientists.
Bed and Breakfast in Cadier en Keer
We also discovered some hills in the Netherlands that weren't man-made. We had to travel 2.5 hours to Maastrict, near the borders of Belgium and Germany, to find them but it was well worth it. We rode our bikes through the small towns, up and down the hills and found a small bed and breakfast to stay for the night (after trying 9 other hotels which were all booked). We happened to show up in this small town on the night of a local festival. They explained the festival to us as a bunch of married men planting a tree to symbolize new life. This sounded like a great festival to me until I realized that they actually cut down a perfectly healthy tree and removed it roots and then planted it in cement. But it was a fun experience anyway.
Monday, June 15, 2009
Author: Robert Bair
It has been a very long and laborious week. Bright and early Monday morning I started the first portion of the absorption experiment. I set up 27 bottles containing either tap water (as a control) or a highly diluted solution of zinc and duckweed. Measuring out an exact amount of duckweed was quite a challenge. It was during this part of the experiment that I learned a very valuable lesson; duckweed sticks to everything. It sticks to glassware, stirring rods, pipettes, fingers, and my lab notebook. It also likes to sneak into places it shouldn't go. I found a piece of duckweed stuck to my backpack, which I had left outside of the lab. I still don't know how it got there.
Once in the bottles, the duckweed was left to absorb the metals for 30 hours. After the 30 hours I started on the “desorption” part of the experiment. This part of the experiment is done to see how much of the metal is simply absorbed (a process which is reversible by simple pH change) and how much is actually uptaken by the plant (not reversible). It was during this part of the experiment that I wished I had eight or more arms. I had to take the plants from each bottle and place them into three different solutions: EDTA, CaCl2 and HCl. For each different solution I needed to put them in for three different times. I found myself at a loss for limbs… Octopuses would make excellent research assistants…
Once the desorption experiment was concluded I had to desiccate the plant samples. While these where in the oven, I was free to start the metal sampling. It was the first time I really used the AAS flame and the TOC. The AAS flame is a really fun piece of equipment to use. It doesn’t have an auto sampler, so you have to manually insert each sample. I enjoyed watching the flame change hues with each new sample.
The experiment isn’t over with. I still have to plot my results and I still need to digest my plant samples in a microwave (I wish this piece of equipment had a more interesting name). I have run out of “influent” to refresh my plants. I will have to go to a wastewater treatment plant with a bucket sometime later this week. I’ll have more info on this as time goes on.
The experiments usually take all day long. I haven’t had too much time to do anything else. I have started making myself a tent. As you might be able to tell by now, I spend most of my spare time building things. I’ll have pics of the tent once I am done.
Sunday, June 14, 2009
Thursday, June 11, 2009
This week, we are actually running the batch experiment to analyze the affect of calcium and pH on arsenic removal with granular ferric hydroxide. The batch experiment didn't sound too difficult to run. We have 24 different conditions, which are broken down into 4 days (as we are unable to manage so many of them when fixing the pH). We have been doing this since Monday (June 8) and it has become kind of a routine - weights out the adsorbents; mixes 6 solutions with different chemical concentrations (already weighted out last week) and pH; puts each solution and its adsrobent in a bottle; places them on a platform shaker; collects samples one hour, every two-hour (for the first eight hours), and twenty four hours after pH fixation; and cleans up before leaving. As we have been doing the same thing so far this week, I didn't write a blog on the same routine everyday to make you (and me) bored :P
The bottles on a shaker with two pH probes for monitoring.
And more bottles.
The cart with what we needed.
Samples from Monday and Tuesday.
Samples from Wednesday and today.
There are more coming in the next few hours.
(Should be 156 samples in total).
Although the works are routine, it is tedious to run these batches. First of all, it isn't easy to maintain the pH over time. I don't know if the pH doesn't like me or what, but it doesn't really stay constant on me. I have to adjust the pH every now and then. Yes, there have been some down time in bewtween (like this one which I am writing this blog :D ); but to ensure the pH doesn't go beyond the tolerance, I am almost always in the shaker room monitoring the pH. Furthermore, the duration of the day is long... We have to be here at 7:30 AM for preparation and wouldn't be able to leave until 7:30 PM after cleaning up.
I would have thought that someone would develop a computer system/equipment to do all these. All you need to do is just put in the solution, enter the pH/conditions, and push the start button. But I guess not (at least not in UNESCO-IHE), otherwise, I would have been using it.
Anyways, we will do something different tomorrow. We would run all our samples thru the AAS for arsenic and calcium. Hope to have some good results and can conclude something out of this experiment.