ABSTRACT
We studied the effects of Mixing Intensities (MI) and Polyacrylamide (PAM) addition dosages on the co-digestion of Waste Activated Sludge (WAS) and waste Waste Wine Distillate (WWD) at 35°C and 55°C. The experiments were conducted in eight identical laboratory-scale 51 digesters. Two mixing intensities were used. Results showed that, compare-d to Low Mixing Intensity (LMI), High Mixing Intensity (HMI) did not obviously improve biogas production with the addition of PAM (12 g/kg TS). This was possibly because at the low PAM concentration LMI might be sufficient to provide adequate mixing. With the addition of PAM (24 g/kg TS), a higher Volatile Fatty Acid (VFA) accumulation was observed under LMI conditions. This was possibly because at higher PAM concentrations LMI might not be sufficient to provide adequate mixing. Compared to LMI, the biogas production with HMI at 35°C and 55°C increased by 7.7% and 22.3%, respectively. In addition at 35°C, the difference in effluent Adenosinetriphosphate (ATP) concentrations between of the two mixing intensities is negligible, while at 55°C, while at 55°C, the difference in effluent ATP concentrations between of two mixing intensities is marked.
