Anaerobic methane oxidation in granular sludge reactors for sustainable wastewater treatment


This project was conducted in the department of biosystems engineering at the University of Gent and was supported by the seventh framework program – Marie Curie Actions – as being part of the Intra-European Fellowships (IEF) Call: FP7-PEOPLE-2012-IEF/IIF/IOF

Besides the quality of the treated wastewater, secondary objectives dealing with the sustainability of wastewater treatment are gaining importance. This has resulted in several important innovations over the last 20 years, such as granular sludge reactor technologies and innovative nitrogen removal techniques based on anaerobic ammonium oxidation (anammox). In granular sludge reactors, biomass is grown in the form of dense, fast-settling granules, resulting in compact wastewater treatment systems which allow a high loading rate. The

anammox conversion comprises the conversion of ammonium and nitrite to nitrogen gas by autotrophic, slow growing micro-organisms. Nitrogen removal techniques based on this conversion result in substantial savings in aeration costs and external carbon source addition costs compared to conventional nitrification-denitrification over nitrate, at the same time minimizing CO2 emission and sludge production. Recently, anaerobic methane oxidizing bacteria (anMOB) have been discovered and first attempts have shown that a combination of anMOB anammox bacteria for a simultaneous nitrogen and methane removal from wastewater is possible.

This project concerns the optimization in terms of design and control of a granular sludge reactor for simultaneous anaerobic methane and nitrogen removal, to combine the advantages of anammox-based granular sludge reactors with the removal of methane, a strong greenhouse gas. The project combines mathematical modelling and numerical simulation with an experimental approach based on lab-scale ractors.

Figure 1 A) schematic view as well as B) simulation result of adistribution of (♦) anammox and (■) ndamo bacteria as well as (●) inerts as a function of granular diameter.

Project administration

Researcher: Mari Winkler

Funding: EU - Marie Curie Intra-European Fellowship (IEF)

Project duration: 01.06.2013 - 15.01.2015