Full scale experiences with anaerobic pre-treatment of wastewater in the food and beverage industry in Germany

In Germany, there are currently 106 full-scale anaerobic treatment plants treating industrial wastewater. This paper describes the operational experiences of several industries (beet sugar, starch, pectin, brewery, distillery, vegetable) which undertake anaerobic wastewater treatment, with particular emphasis on specific wastewater problems and their solutions. Also presented are experiences of the handling of high nitrate concentrations, with the treatment of mixtures of industrial wastewater from different origins, with the chance to prevent the emergence of lime, magnesium ammonium phosphate (MAP) or aluminium precipitation. This paper deals with the first municipal wastewater treatment plant combined with a separate anaerobic stage to treat a wastewater mixture of several small factories. One particular asset of this plant is the construction of the acidification tank: using the ''teapot effect'' to enrich the solid material in the centre of the bottom, the solids can be taken from the bottom of the tank and pumped to the municipal sludge digester. (C) 1997 IAWQ. Published by Elsevier Science Ltd.