Since the development of the UASB process in the 1970s this process has been widely applied for the treatment of industrial effluents. Effluents from alcohol producing industries are mostly highly polluted and therefore in principle very suitable for anaerobic treatment.
Distilleries use different kinds of raw materials such as sugar cane juice, sugar cane molasses, sugar beet molasses, wine or corn for the production of alcohol. The use of different materials and the different processes applied, result in a wide variety of effluents produced. The process conditions under which good results of the anaerobic process are obtained depend heavily on the type of distillery effluent being treated. The choice of the right set of process parameters for every type of distillery effluent has shown to be of crucial importance for the anaerobic process.
Experience of anaerobic treatment on effluents from different alcohol-producing industries over a long term period are discussed. Special attention is given to the treatment of effluents from sugar cane based distilleries with very high COD concentration of 60 000 to 160 000 mg COD 1−1. Despite expected toxicity problems arising from the high concentrations of COD, sulfide and salts, anaerobic treatment with the UASB process proved to be successful in treating distillery effluent.