Abstract
<jats:p>Anaerobic digestion (AD) is a well-established technology for waste management that can recover energy in the form of biogas. However, the production of this biofuel is affected by a series of drawbacks during its production. For example, long reaction times, process instability and low conversion efficiencies all lead to a decrease in the degradation of organic matter and low biogas production. For this reason, the scientific community has seen the need to develop alternatives that improve the performance of AD, for example, via the addition of various nanoparticles (NPs) into the AD medium. In this chapter, we discuss the trace metals required by the enzymes involved in methanogenesis as cofactors. Also, the importance of NPs in the AD process is discussed in the context of increasing biogas production, improving stability and/or improving the removal of organic matter. Likewise, the physical and morphological characteristics and properties of NPs at the nanometric level are discussed. An analysis is also made of the toxicity that some NPs present to the development and proliferation of anaerobic microorganisms. Finally, some key points that were identified during the development of this chapter, and which are of great interest to the scientific community and will allow the development of new areas of research to increase and improve the production of biogas are addressed.</jats:p>