Anaerobic treatment of winery wastes in suspended and attached growth biomass reactors

The operational performance of anaerobic batch reactors treating winery wastes from wineries in Friuli Venezia Giulia region was investigated under mesophilic conditions. Four 5 l anaerobic reactors were set up in a controlled temperature environment of 35 °C with mixing to suspend the sludge solids. The aim was to compare the behaviour of suspended and attached growth biological processes under different substrate and biomass concentrations. Reactors were seeded with anaerobic sludge from full scale UASB treating brewery wastewater and with selected lyophilized anaerobic bacteria. The reactors used for attached growth biomass tests were filled with small floating supports of wood and polyethylene material. The experimental results showed that the Specific Methanogenic Activity, when attached growth reactors were employed, was slightly greater than that of suspended growth reactors operated under the same conditions. A final COD balance was made for validating the experimental results.