The pulp- and paper-industry generates large volumes of highly heterogeneous wastewaters containing compounds from wood or other raw material, process chemicals and compounds formed during processing.
The wastewaters from mechanical pulping and secondary fiber pulping as well as the condensates from chemical and semi chemical pulping are typically non-toxic to methanogenic degradation and contain easily degradable organic compounds.
Consequently, anaerobic digestion is an attractive treatment alternative for these effluents since the early 1980's. Amongst various anaerobic systems, the UASB and EGSB are the most applied anaerobic reactor systems in the pulp & paper industry.

Amongst various anaerobic systems, the UASB and EGSB are the most applied anaerobic reactor systems in the pulp & paper industry.