Breweries and other beverage production
Brewery wastewater appears in a result of washing, raw stock steeping and sprouting, washing the processing equipment, brew kettles, fermenters, woods, bottles, floors and walls, separation wort from hop, bottling and other technologic processes. The amount of wastewater and the concentration of contaminating impurities depend on the beer production processing technique on the factory. Usually, brewery wastewater is no-toxic, biodegradable and seemed to contain large amounts of suspensions and organic pollutants which are dissolved. Therefore COD is high (it may reach 4000 mg O2/l), while BOD equals about 1500 mg O2/l. All the organic substances contained in brewery sewage consist mainly of sugars (starch, fiber), other starches, proteins, as well as fats, yeast and hop residues. The chosen technique of brewery wastewater treatment is based on the local demands.
For reducing the pollutants discharging it is necessary to prevent organic sediments joining wastewater and to utilize them for cattle feeding. Also, for successful brewery waste management, the way of flushing should be changed and the circulating water supply has to be implemented. But let’s return to the treatment itself. In the beginning, it’s better to use some mechanical treatment equipment (screens, sedimentation, and sieves). The first step helps to control the flow, its direction and to correct the water PH.
Biological treatment and water clearing are the next two steps in brewery wastewater treatment. With anaerobic reactors, it is possible to achieve a reduction in the organic load by 70-80% and good biogas production without producing much sewage sludge. There are three types of such equipment: Upflow Anaerobic Sludge Blanket (UASB), modified Internal Circulation (IC) and Expanded Granular Sludge Bed (EGSB). Then activated sludge in aerated tanks and Sequencing Batch Reactor (SBR) are utilized resulting in a reduction in organic load of 95%.
Most brewery waste has commercial value as a raw material for other food industries (feed processing, foodstuffs). The best way for getting rid of pollution in wastewater is to stop disposing of brewing wastes as a sewage product but to start recycling it off. Such approach will be good not only for the environment but for economics too. The brewing process now produces so much waste, but it is possible to reduce it with the help of effective wastewater treatment.