Impact of Hydrothermal Pretreatment Parameters on Mesophilic and Thermophilic Fermentation and Anaerobic Digestion of Municipal Sludge

Four parameters affecting hydrothermal pretreatment (HTP) of municipal sludge prior to anaerobic digestion and fermentation were investigated. Partial factorial design including several key HTP at two distinct levels, temperature (170 190 °C), retention time (RT) (10 30 min), pH (4 10), solid content (SC) (4% 16%), studied. Further, the impact on mesophilic thermophilic was explored compared. Results revealed a significant effect all COD solubilization, VFA, methane yield. There correlations between process responses such as VFA yield found increase solubilization production 15 20% during in relation treatment. All parameters, SC, temperature, pH, RT, important contributing factors digestion. The highest 269 mL CH4/g TCOD added observed SC (16%) (10) lower °C) RT (10). is expected be combined with other intensification routes treat waste high contents improving processes.