No abstract

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−.