Growth microalgae could be used as co-substrates in anaerobic digestion processes to produce biogas of a high-calorific value, which could be expended as heat or electricity in cogeneration engines. Lignocellulosic and high-carbon content wastes, due to their characteristics, hinder anaerobic digestion processes. The use of microalgae as a co-substrate with high-carbon content residues can adjust the C/N ratio and thereby obtain, in some cases, a higher biogas production and greater biodegradability of wastes during anaerobic digestion than without co-digestion options. In addition, microalgae and cyanobacteria are photosynthetic microorganisms that can produce oxygen and oxidize the organic matter and NH4+ contained in wastewaters. The growth of microalgae in industrial effluents and wastewaters can considerably reduce the organic matter contained in them and their pollutant load. This growth can take advantage of the nutrients that still remain in industrial effluents, avoiding the use of clean water for the growth of biomass. The chapter will focus on an overview of microalgae anaerobic co-digestion with different wastes and the benefits of this option.
Part of the book: Microalgal Biotechnology