More than one third of drinking water wells in Europe has too much nitrate according to the present standards (<50 mg NO3—N/L). Typically this is solved by dilution of the water with low-nitrate streams, or denitrification using organic electron donors. Bioelectrochemical systems (BES) allow to directly use electricity as electron donor via a cathode, coupled to an anode that can assist in pH neutralization and post disinfection. Whereas the concept is well known, a key impediment is that drinking water comes at high flows (10s of cubic meters per hour) which is not compatible with most BES designs. A solution for this is to develop a fluidized bed BES, in which electroactive biofilms colonize carbon based particles that intermittently become charged by a contacter electrode. This concept allows scale up of the BES to cubic meter size while maintaining low distances between anode and cathode which is crucial for low cell voltage. There were, however, many unknowns at the time our research started. Firstly, the knowledge on electroactive biofilms, growing in a cathodic fluidized bed system, was limited and it was not known whether they can effectively store charge. We have now established that this is feasible, albeit at low level requiring materials interventions to improve the capacity. Second, the systems have not been scaled up for this and operation over longer time periods has not been demonstrated. In my presentation, I will show some of our data obtained from the running pilot in Girona, Spain.
About the speaker:
Prof. Dr. Ing Korneel Rabaey (20/11/1977) is professor at the Center for Microbial Ecology and Technology (CMET), Department of Biotechnology at Ghent University as well as honorary professor at The University of Queensland. He is one of the founders of CAPTURE (www.capture-resources.be), a center focusing on resource recovery in the fields of Water, Carbon Capture and Utilization and Plastics to Resource. He is founder of HYDROHM (www.hydrohm.com), a company focusing on electrification in the water sector. His main research efforts are on:
1. Resource recovery from wastewater, particularly metals and nutrients
2. Decentralized treatment technology
3. Bio-electrochemistry and electrochemistry for bioproduction and bioremediation
4. Microbial protein production as a novel route for carbon neutral or negative feed, food or polymer
Typically a combination of electrochemical and/or microbial approaches is used to achieve formation of added value products. He is the author or co-author of over 200 refereed articles attracting over 34,000 citations, listing him as an ISI Highly Cited Researcher. He is Fellow of the International Water Association and was laureate of the Royal Academy (Belgium) in 2016. He is executive editor in chief of Environmental Science & Ecotechnology, as well as Editorial Advisory Board member for Environmental Science & Technology.