title: Digestion and degradation, air for life.
abstract: Anaerobic degradation of dead biomass is a natural gasification process, an anaerobic crematorium producing a very useful end-product composed of methane and carbon dioxide, generally polluted with small amounts of some malodorous and quite toxic volatile S-compounds. It leads to the production of essential building elements for new life. This exciting field became my faith, vision, hope and expectation. This paper intends to present a reflection of more than three decades of research, teaching and advertisement in the field of sustainable environmental protection technologies, particularly of systems based on anaerobic digestion and the biological sulphur cycle. Considerable progress has been made during these decades worldwide, both in the basic understanding of the various processes and concepts, but also in the implementation of these systems, despite the fact that particularly the implementation frequently proceeded very laboriously. The difficulties certainly can no longer be attributed to technological limitations and/or insufficient understanding of the microbiology and chemistry only, but mainly to the frustrating social rigidity and short-term self-interest in all sectors of our society. By combining anaerobic processes with other microbiological degradation or transformation processes, like those based on the biological sulphur cycle, micro-aerobic and conventional aerobic and anoxic processes, ideal conditions can be created to valorise residues (wastes) from domestic, industrial and agricultural origin. It is simply not just "technology", but also a route to achieve more sustainability and justice in society. It is a fight against conservative establishments. Decomposition, disintegration disbandment, it also stands for deliverance and liberation, space and air for continuation of life.
authors.affiliation: Sub-Department of Environmental Technology, Wageningen University, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Lettinga
mesh_terms: D001421:Bacteria, Anaerobic / Q000502:physiology*; D018533:Biomass; D019149:Bioreactors; D002245:Carbon Dioxide / Q000032:analysis; D003247:Conservation of Natural Resources; D008697:Methane / Q000032:analysis; D013455:Sulfur / Q000378:metabolism; D013672:Technology; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D002245:Carbon Dioxide; D013455:Sulfur; D008697:Methane