Warm concentrated industrial wastewaters are preferably treated in an anaerobic reactor for reasons of energy generation and low surplus sludge production. Problems to be solved in the practical application concern a low growth rate of the micro-organisms, their low settling rate process instability, and the need for after-treatment of the noxious anaerobic effluent which often contains NH4+ and HS−. The use of biomass immobilized on small suspended carriers (< 0.5 mm) has proven to be a suitable mean to overcome most of these problems. Results are presented on
pilot and full-scale pretreatment of industrial wastewater in an anaerobic 2-stage fluidized bed reactor for CH.-production.
laboratory and pilot scale post-treatment of the anaerobic effluent, which contains NH4+. and HS2− in an aerobic air-lift suspension reactor for the production of NO3− and SO4−.