(UNESCO / Japan Young Researchers' fellowships programme)

Constructed wetlands for use in Uruguayan dairy waste waters using endogenous plants

Summary of research carried out: 
Constructed wetlands for use in Uruguayan dairy waste waters using endogenous plants

This fellowship gave me the extraordinary opportunity to spend three exhilarating months at one of the most important institutions worldwide that deal with waterrelated problems with special emphasis on developing countries and those in transition, the UNESCO-IHE Institute for Water Education. In my home country, Uruguay, I am developing the use of alternative sewage treatment facilities, in particular constructed wetlands, but little to nothing is known about the abilities and performance of native plants for such uses, which is why I directed myself towards the IHE for guidance and support two years ago.

In Delft, I was given the possibility of conducting topic specific research where we compared the root oxygen loss of four different wetland species, three of them native to Uruguay, and the changes in nutrient composition which showed that plants respond differently to sewage water. It was particularly interesting to see the high efficiency of water quality enhancement of two previously untested plants. This is very promising since it points to the ability of some endogenous plants to be highly successful for use in constructed wetlands in Uruguay.

Further, I undertook an experiment about the physical oxygen transfer rates in a gravel bed wetland mesocosm, which represents a clue element in the understanding of the functioning of these systems. This study was part of a series of studies that had been performed at the IHE and confirmed the previous findings. We were able to quantify the amount of oxygen that was exchanged with the atmosphere by using the innovative technique of propane as a tracer gas.

Nevertheless, the IHE is, in the first place, an educational facility and I therefore also had the chance to participate in the three-week short course “Water quality modelling” where I was introduced to some of the modelling tools for river and water quality management, such as SWAT. Through this class I have identified the necessary data to build a successful model for a small watershed in south western Uruguay and have contacted institutions and agencies in order to obtain this information to complete the model. This will be the first time that SWAT will be applied in Uruguay and I am confident that it will be used for other projects, such as the large River Santa Lucia Basin.

Lastly, one of the purposes of the stay in Delft was the interaction with my supervisors, professors and fellow students to exchange ideas and points of views on the thematic of sustainable sewage treatment facilities, the challenges of their realization and the success stories. This has certainly taken place and I was given ample opportunity to take part in several seminars, Ph.D defences and talks by guest speakers from all over the world. I also had the opportunity to further narrow down and clarify my research topic and Ph.D proposal which I will now proceed to write in the forthcoming months.


17 September 2009