BIOFILM CHARACTERIZATION AND ACTIVITY ANALYSIS IN WATER AND WASTE-WATER TREATMENT

Biofilm composition and activity are two important parameters for the successful operation and control of fixed film processes in water and wastewater treatment. Widely used parameters for biofilm characterizat ion are biofilm thickness, total dry weight and total cell count, Thes e parameters are, however not sufficient to describe biofilm activity. Improved analytical methods and procedures are needed in order to und erstand the physiological behaviour of the fixed biomass. Common metho ds used to analyse biofilms are critically reviewed in terms of their principle, complexity, reproducibility, sensitivity and cost. Conventi onal and advanced analytical methods are classified in three main cate gories: (1) biofilm formation and structure; (2) biofilm composition d escribed in terms of total biofilm amount, specific biofilm components and cellular components; and (3) biomass activity descriptors. The di scussion focused on the potential of these methods for accurate biofil m characterization and biomass activity estimation in fundamental rese arch and for the practical needs of wastewater treatment operation and control.