The performance enhancements of upflow anaerobic sludge blanket (UASB) reactors for domestic sludge treatment - A State-of-the-art review

► We review various enhancements made on the anaerobic digestion of domestic sludge. ► The aspects considered are granulation or start-up of UASB reactors, climate temperature constraints and effluent quality. ► We provide a database and perspectives for future improvement.