Cheese factory wastewater treatment by anaerobic semicontinuous digestion

Abstract

The processing of wastewater from a cheese factory in a semicontinuous anaerobic digester was studied. The experimental set-up consisted of six thermostatically-controlled digesters in a bath at 35±1 °C, and magnetically stirred at 100 rpm. The best feeding for the culture medium was 0.633 g 1 −1 day −1. The minimum hydraulic retention time was nine days. The efficiency of treatment varied between 90 and 78%. The composition of biogas was of high quality, with 67% of methane, and no trace of H 2S.