Adhesins: the missing link for activated sludge bioflocculation?

The cost efficiency and sustainability of biological wastewater treatment systems highly depends on the bioflocculation ability of the so-called activated sludge bacteria which should ensure a proper sludge-water separation. The most important component of activated sludge flocs are the bacterial microcolonies which dictate the overall strength of the floc. This research will investigate whether adhesins play a role in strong microcolony formation. Adhesins are non-enzymatic proteins on the outer cellular membrane that can bind to specific receptors. They have been reported to play an important role in, e.g., yeast bioflocculation and biofilm formation, but are thus far not thoroughly investigated in the context of activated sludge bioflocculation. This project encompasses (i) a strong experimental part in which a combination of wet chemical, molecular genetic, proteomic and (fluorescence) microscopy techniques are exploited to monitor the presence of adhesins in microcolonies and to unravel their functionality and dynamics and (ii) a modeling part to translate the dominant binding forces into aggregation principles for population balance models, enabling future prediction, optimization and control of sludge-water separation performances.

Keywords:activated sludge, bioflocculation, microcolonies, population balance modeling, adhesins

Disciplines:Catalysis and reacting systems engineering, Chemical product design and formulation, General chemical and biochemical engineering, Process engineering, Separation and membrane technologies, Transport phenomena, Other (bio)chemical engineering, Biomaterials engineering, Biological system engineering, Biomechanical engineering, Other (bio)medical engineering, Environmental engineering and biotechnology, Industrial biotechnology, Other biotechnology, bio-engineering and biosystem engineering