Anaerobic digestion (AD) is one of the most energy-efficient technologies for treating biodegradable waste since biogas can be generated as a by-product. AD is a biochemical process mediated by a consortium of microorganisms without oxygen in four stages: hydrolysis, acidification, acetogenic and methanogenesis. The addition of iron-based nanoparticles (Fe-NPs) aims to boost the AD process to enhance the biogas...