BRIDGE News

Madalena Alves, assistant professor at the Department of Biological Engineering from the University of Minho won the 2nd edition of the Lettinga Award. The Lettinga Award was initiated in 2001 and is financed by three Dutch Environmental Engineering companies: Paques Natural Solutions B.V., Royal Haskoning and Biothane Systems International. The intention of this award, a prize of 25.000 Euro, is to stimulate innovation in the field of anaerobic technology for wastewater treatment aiming at cleaner production or recycling, sustainable development and/or resource conservation. This may concern sustainable treatment concepts of industrial or domestic wastewater, but also activities that are focussed on awareness, implementation, knowledge transfer and demonstration of sustainable environmental biotechnologies. The innovative projects that can be submitted may take place all over the world, in both developed and less developed countries. Innovation, applicability, and reality are the most important judging criteria.

In this 2nd edition of the Lettinga Award, 30 proposals were submitted from all the world. The judging committee has six members, three who work in a scientific environment and three with more practical knowledge:

• Prof. Dr. Ir. Mark van Loosdrecht, Technical University of Delft, The Netherlands
• Prof. Dr. Ir. Willy Verstraete, University of Gent, Belgium
• Prof. Dr.-Ing. Peter Wilderer, Technical University of München, Germany
• Ir. Hans Maas, Royal Haskoning, The Netherlands
• Dr. Ronald Mulder, Paques Natural Solutions B.V., The Netherlands
• Ir. Bram Versprille, Biothane Systems International, The Netherlands.

Madalena Alves received the Award on the 2nd September 2004, in Montreal, Canadá during the 10th World Congress on Anaerobic Digestion.
 
CV:
Madalena Alves obtained the degree in Chemical Engineering in 1987 from Oporto University and initiated her teaching career in 1988 at the University of Minho, Department of Biological Engineering. She got her Master in the Instituto Superior Técnico in Lisbon in 1992 and her Ph.D. in 1998 at the University of Minho. She is now assistant professor and responsible for the course on wastewater treatment technology from the 5th year of the Biological Engineering degree, amongst others. Her research activity is focused on the anaerobic waste(water) treatment processes aiming the efficient methane and/or hydrogen production. For that she studies the microbial consortia involved using techniques that include activity, biodegradability and toxicity assays, molecular tools and image analysis. She published about 25 papers in international journals and more than 30 full papers in proceedings of international congresses. She is one of the 12 members of the IWA task group on “Harmonization of Activity, Biodegradability and Inhibition Assays”. She is responsible for several research projects funded by the Portuguese Science foundation (FCT), Innovation Agency (AdI) and also UE. She participated in several national and international Ph.D and Master committees and she supervises several PhD and Master students.
 
 
Project Summary
The research work initiated about 6 years ago on the anaerobic biodegradation of Long Chain Fatty Acids was focused on basic studies that conducted and support the development of a new technology for efficient mineralization of lipids under anaerobic conditions. The research work initially coordinated by professor Manuel Mota and presently supervised by Madalena Alves will involve also three researchers in this future project: Alcina Pereira (Post-Doc), Diana Sousa and Ana Júlia Cavaleiro (both PhD students).

If an effluent with an high lipid content is fed to a continuous high rate anaerobic digester, a significant accumulation of Long Chain Fatty Acids (LCFA) onto the sludge aggregates (flocs or granules) is observed, without further mineralization to methane. That accumulation is progressive and, after some time, the sludge becomes surrounded by an whitish foam and tends to float, leading, most of times, to a severe washout. This happens not only with granular sludge reactors, but also with fixed bed reactors. This fact, associated to the accepted idea that LCFA were highly toxic to the anaerobic consortia, imposed that lipids had to be removed from any wastewater before the anaerobic treatment step. Therefore, the high methane potential of these compounds was lost.  The obtained results gave new insights on the mechanisms that are on the basis of the LCFA accumulation onto the anaerobic sludge. It was observed that anaerobic sludge had the capacity to mineralize the LCFA associated to the cells by mechanisms of adsorption, precipitation or entrapment, but not those that remain disperse in fine emulsions in the bulk medium. Furthermore, after the mineralization of these biomass-associated LCFA, the specific methanogenic activity of the sludge was enhanced, being able to accumulate and mineralize a new LCFA load. These facts contradict the accepted theories about the severe and irreversible toxicity of LCFA and clearly suggest that only a reversible inhibition occurs, probably a simple physical transport limitation effect. The main practical result of this research is that a sequencing batch reactor (SBR) based process will be the most suitable way to efficiently mineralize effluents with high lipids content. Therefore, the aim of this project is to develop, construct and demonstrate a new anaerobic reactor concept based on SBR technology to be applied in the efficient mineralization of a real effluent with high lipids content.