ABSTRACT
The recovery of nutrients, reuse of water, production of intermediates, and generation of energy have become important incentives for the treatment of wastewater from both industrial and municipal origins. The conversion of organic matter to methane is a complex process that is carried out in four sequential steps, namely, hydrolysis, acidogenesis, acetogenesis, and methanogenesis, by roughly three groups of microorganisms. One of the latest developments in anaerobic wastewater treatment is the application of anaerobic membrane processes. These processes are especially suitable for industrial wastewaters with high salinity, high temperature, or wastewaters containing toxic, but biodegradable compounds. Industrial wastewaters of different origin give different methane production yields depending on production routes and technologies used. The amount of methane produced plus the produced biodegradable dissolved chemical oxygen demand (COD) per volume wastewater equals the hydrolyzed COD. Anaerobic treatment of municipal wastewater is so far mainly applied in tropical and subtropical areas.
