ABSTRACT
The goal of successful treatment of sewage with an anaerobic process has been sought for over a century.' Purification of wastewater to high quality in a simple process that produces useful clean energy, without creating secondary biological sludges, is an admirable goal, but was thought to be impossible.' The application of the slow growing methanogens to cool and dilute wastewaters, such as domestic sewages, represents one of the more difficult tasks in the microbial world.
