Abstract
The water footprint of wineries is typically more than 1 L water/L wine. In the European context, this annually equals to over a hundred million hectoliters of water, most of which eventually become wastewater. The winery wastewater is known to have high organic loads, most frequently quantified by chemical oxygen demand (COD). Particularly during the vintage season, the discharge of winery wastewater with extreme COD values can paralyze municipal wastewater treatment plants. As a result, the treatment plants pose strict limits on wastewater parameters. This forces wineries to either transport the wastewater to specialized facilities capable of handling the wastewater extremities, or invest into their own wastewater treatment plant. Since wine has been historically produced by small wineries, either option economically challenge these often family-owned companies. This work reflects the need for robust wastewater treatment technologies that would be able to handle winery wastewater parameters’ fluctuations throughout the year and the abovementioned peaks. The technologies are categorized into physicochemical, biological, membrane, advanced oxidation and combined processes. There are a number of treatment methods that have shown a COD removal rate of over 90 %. However, they significantly vary in size, process flexibility and maintenance difficulty. Some alternative processes are also critically evaluated in the context of circular economy and water reuse, which can further improve the process economy for small- and medium-sized wineries.
