Digestate management for high-solid anaerobic digestion of organic wastes: A review

Digestate management for anaerobic digestion (AD) is becoming a bottleneck of the sustainability of AD plants when the use of digestate for agricultural application is restricted due to nutrient surplus and low market acceptance. Digestate quality and treatment in high solid anaerobic digestion (HSAD) can be better than conventional low-solid system. The rheological behavior of digestate in high solid anaerobic digestion (HSAD) can have a great impact on the energy consumption of digestate management. After post-conditioning guided by rheological parameters, the solid digestate can be further treated based on the integrated solutions to enhance the energy efficiency or nutrients recovery. The environmental impacts for some core parts of those integrated systems were also evaluated in this study. This article presented a critical review of recent investigations of digestate management for HSAD, especially focusing on the rheology of HSAD digestate, integrated solutions and their environmental performances.