Promotion of direct interspecies electron transfer and potential impact of conductive materials in anaerobic digestion and its downstream processing - a critical review

Addition of conductive materials (CMs) has been reported to facilitate direct interspecies electron transfer (DIET) and improved anaerobic digestion (AD) performance. This review summarises the benefits outlines remaining research challenges addition CMs with a focus on downstream processing AD. CM may alter biogas quality, digestate dewaterability, biosolids volume, centrate quality. Better quality observed due adsorption H2S metallic CMs. The results in an increase solid content thus additional requirement for sludge dewatering handling final volume disposal. highlights need more at pilot scale validate evaluate selection, doses, material costs, impact processes. lack process AD is highlighted.