The given example of an anaerobic/aerobic wastewater treatment plant ((WWTP) for a big German brewery shows that it is possible to reduce the discharged values to a very low level, much lower than the minimum requirements of Appendix 11 of the German General Wastewater Administration Rule, which applies to breweries. This means that the present state of technology has been updated.
Tests on a semi-technical scale were carried out and found to be necessary to find the most suitable design for the wastewater treatment plant. Running the tests in the brewery, it became obvious that disinfectants had to be substituted until a stable COD elimination was achieved. Full-scale tests in the plant would not have been feasible. Numerous modifications were carried out in the brewery to reduce the amount of cleaning and disinfectant agents as well as the amount of AOX, EDTA, NTA and aluminium used.
The following article presents the findings of the investigations about the ammonification of organic nitrogen, bulking sludge and substrates for denitrification. Furthermore it demonstrates the low operating costs of anaerobic pre-treatment, even in combination with an aerobic stage and filtration unit.