Research, Berlin, and fun things of Delft

Laurel

For the duration of my research here at UNESCO-IHE, I am working with Dr. Diederik Rosseau. The topic we are working on is removal of heavy metals from simulated industrial wastewater via sorption to duckweed, Lemna gibba. Specifically, I will be investigating Zinc.

Interesting first insights into the project I forsee that will potentially be challenges are as follows. First of all, I just took Dr. Trotz's aquatic chemistry course at USF, and I really want to make some speciation diagrams for the metal solutions I will be making up for the experiments. This will be possible to do for initial speciation, but more difficult once the duckweed is introduced to the solution, taking up nutrients and some zinc species, and thus making plotting speciation over time probably very difficult.

Second, zinc plays a role in photosynthesis. Are there zinc species that are more easily uptaken by the plants, and if so, in what conditions are these species present (pH, etc.)?

And finally, the most challenging aspect of this project is that past students working on the same research objectives have not been able to close the mass balance on the heavy metal, i.e. a good percentage of the mass originally introduced into solution was not accounted for as adsorbed to the plant, uptaken by the plant, or precipitated from solution. It is not clear why it was not possible to account for this mass. I am certainly going to give it my best, learn as much as I can in the process, and hopefully have good results in the end.

Last week, other than reading up on metal sorption to aquatic plants, my first mission for the lab was not actually in the lab. I got to ride my new road bike around Delft searching for duckweed. I found some Lemna minor, another species of duckweed. In the process, I came across this beautiful lake to the east of the city, a park full of kilometers of bike trails, and I saw a gorgeous pheasant on a trail in the middle of these woods filled with birdsong. In the end, I collected Lemna gibba from the pond near UNESCO-IHE, but I got to see another beautiful spot in Delft in the process of searching.

The Lemna gibba is currently growing in trays under fluorescent bulbs in the lab on primary effluent from a local wastewater treatment plant. Photos later.

Outside of work, which is good, we traveled to Berlin for the long weekend we had off of work. I loved Berlin. I can't properly explain it, but I liken the atmosphere in Berlin to Boston. It is the only European city I have been to that reminded me of the city of Boston, where I lived for 5 years. Of course, the history is different, the sights are different, the language is different, I just noticed similarities.

Other than learning more WWII history in 2 days than I ever learned in high school, the most notable thing I loved about Berlin was all the musicians on the streets and in the subways. I have never heard so many really good musicians in one city. One man played the glass harp, a series of wine glasses of different sizes tuned by adding different amounts of water to the glasses. He played many Bach pieces. I bought his CD, he was so good!

And lastly, I am enjoying the company of so many international students in one place. It makes me want to come back to Delft, for longer than a summer.