Fate of pathogens and micropollutants during organic wastes and by-products anaerobic digestion - A review

Based on 300 scientific papers, the following bibliographical research deals with the fate of micropollutants (pathogens, heavy metals, organic pollutants) during anaerobic digestion. Different biological and chemical mechanisms allow organic compounds elimination, except from some Polycyclic Aromatic Hydrocarbons (PAHs) and heavy metals which are fixed to the solid biomass, permitting water contamination risks attenuation. Unlike mesophilic digestion, thermophilic digestion is a 'sanitation' process regarding pathogens elimination. However, mesophilic digestion offers an important reliability compared with competitive or complementary processes. In particular, energy recovery from anaerobic digestion allows temperature control and makes easier further sanitation heat treatments. In general, anaerobic digestion represents a tool which can be included in an organic waste treatment line assuming waste selection and good agricultural practices. Otherwise, sanitation problem is still badly handled by waste operators and constructors which have been consulted. Research orientations seem especially interesting in improving knowledge of real industrial processes performances. (authors)