Performance of a Pilot‐Scale, Two‐Stage Anaerobic Digester Treating Municipal Sludge
Abdullah Almatouq, Abdulla Abusam, Hussain Hussain, Mishari Khajah, Hussain Abdullah, Rashed Al‐Yaseen, Mariam Al‐Jumaa, Farah Al‐Ajeel, Mohammed Aljassam, Ahmed ShishterABSTRACT
This study investigated the performance of a two‐stage, pilot‐scale AD reactor for energy generation from sludge produced at Kuwaiti municipal WWTPs. Sludge characterization results showed that all measured parameters were within the optimal range for methanogenic bacterial growth, except the low carbon‐to‐nitrogen (C/N) ratio. In batch mode, the reactor achieved a maximum gas production of 390 L/day with a methane heat content of 3.31 kWh/day. In contrast, in semicontinuous mode, the AD achieved higher gas production of 550 L/day and higher methane heat content (4.22 kWh/day). In terms of sludge treatability, the AD reactor achieved maximum destruction rates of the volatile suspended solids (VSS) of 21% (batch mode) and 16% (semicontinuous). Future research should focus on the selection of suitable waste streams to be used as a co‐substrate to enhance biogas production and on the determination of appropriate and economically feasible pretreatment methods for the sludge.