Energetic Valorisation of Cheese Whey using UASB Technology: a case-study

This study was focused on energetic valorization of cheese whey using UASB anaerobic digestion; whey represents a strongly polluted stream, that needs to be properly treated. In particular, the mountain area of Friuli-Venezia Giulia region was selected as a case-study, due to the presence of a number of cheese factories and a UASB reactor, actually inactive, located in municipal WWTP of Tolmezzo (Ud). The results showed that first and second cheese whey were characterized by extreme COD value, up to 105 g/L, significant solid matter presence (6.63-7.44% TS) and high phosphates concentrations (527-530 mg/L); a major difference between the matrixes was lipids concentration, that was significantly higher in first whey (33.0 g/L versus 2.4 g/L). Elemental analysis highlighted high C (35.8-43.1%) and low N (1.0-2.4%) concentrations of whey solid matter. A useful dilution of whey (1.50 v/v) was used in continuous tests, that were executed both on laboratory and pilot-scale: the results showed excellent COD removal, as high as 84.7%, and a methane production of 0.193 Nm3 CH4/Kg CODremoved, that boosts for anaerobic valorization of this substrate