PROJECT DESCRIPTION
BACKGROUND
The Ottakringer Brauerei produces presently beer and beverages of about 550,000 hl/a and 160,000 hl/a per year. Of the total volume of approx. 5hl of water that is used for the production of 1 hl of beer (or other beverages), approx. 2hl are used in the actual production process (process water), while around 3 hl is wastewater. The process relevant process water output is between 130,000 and 160.000 m3 per year (corresponding to 11.500 m3 per month, with a pollution level of 27 t/COD/month). Currently, this water is fed into the public sewage system. In the context of the planning of a new water supply system, this project came about in order to develop technologies and methods that would allow for the reuse of wastewater with low contamination in the production processes.
OBJECTIVES
The objectives of the project were the evaluation of the use of innovative environmental technologies, including membrane technology for process water and wastewater treatment (nanofiltration/ reverse osmosis) and water recycling as well as the assessment of measures that are relevant both in relation to production and the environment in connection with the development of an internal water supply system. The study included water balances by fractions and an evaluation of the water-saving potential of technologies developed for the protection of the water resources. The project also included an outlook as regards the suitability of the approach in similar industries. The main target of the project was to reach 5 hl of water per 1 hl of beer to less than 3 hl per 1 hl beer and therefore to achieve a water saving potential between 85,000 and 130,000 per year. The project covered four phases: - - Phase 1: base study (soundings, horizon protection, chemical analysis of the groundwater level, investigation of the grading, the geological structure and the structure of the subsoil); - - Phase 2: prototyping (analysis of the water streams in the company, first investigations using nano-filtration and membrane technologies); - - Phase 3: implementation, construction of a reprocessing plant, process optimisation; - - Phase 4: construction of a deep well.
RESULTS
Three of the four project phases were successfully executed. The technical implementation of the water reprocessing plant could not be carried out due to economic reasons and therefore the main objective of the project which was the achievement of a water water saving potential between 85,000 and 130,000 per year was not reached. But all requirements for a rapid implementation were provided. It turned out that prospects for this type of technology are closely related to drinking water prices and wastewater disposal costs. The results that could be drawn from the comprehensive tests carried out with the pilot unit developed under phase 2 of the project (prototype of a filtration system, with a capacity of 1m3 per hour) can be summaried as follows: The recovery of reusable water from process water and wastewater produced in a brewery by means of membrane technology is technically possible. A high water quality can only be achieved through reverse osmosis. Reverse osmosis requires that the water is treated in a preliminary cross-flow micro filtration process. The alcohol concentration in process water and wastewater from breweries can lead to certain problems, if water of drinking quality is to be achieved (COD < 5 mg/l). This problem can be reduced considerably by minimising the alcohol loss in the production process. The above results provided the basis for the implementation of a system that fulfilled the requirements defined for the project. However, the current circumstances did not allow for an assessment of its economic viability. The reverse osmosis unit would have only been economically viable, if the overall costs for water (including wastewater treatment) were greater than 52 ATS/m3. The brewery was currently serviced by the local authority waterworks, which charge a price of 33 A TS/m3 (for drinking water supply and wastewater treatment). The proposed water-saving recycling system could however be a financially viable solution for food processing plants, where water costs are considerably higher while the main parameters are very similar to those of the pilot scheme. Phase three could thus only be partly implemented and was limited to the drafting of the concept of the unit and a study assessing the financial viability of the project. As the current development indicates that drinking water is becoming more and more polluted, it is to be expected that this valuable resource will become more expensive in time so that the implementation of the proposed system could become an increasingly viable solution in the near future. Three of the four project phases were successfully executed. The technical implementation of the water reprocessing plant could not be carried out due to economic reasons and therefore the main objective of the project which was the achievement of a water water saving potential between 85,000 and 130,000 per year was not reached. But all requirements for a rapid implementation were provided. It turned out that prospects for this type of technology are closely related to drinking water prices and wastewater disposal costs. The results that could be drawn from the comprehensive tests carried out with the pilot unit developed under phase 2 of the project (prototype of a filtration system, with a capacity of 1m3 per hour) can be summaried as follows: The recovery of reusable water from process water and wastewater produced in a brewery by means of membrane technology is technically possible. A high water quality can only be achieved through reverse osmosis. Reverse osmosis requires that the water is treated in a preliminary cross-flow micro filtration process. The alcohol concentration in process water and wastewater from breweries can lead to certain problems, if water of drinking quality is to be achieved (COD < 5 mg/l). This problem can be reduced considerably by minimising the alcohol loss in the production process. The above results provided the basis for the implementation of a system that fulfilled the requirements defined for the project. However, the current circumstances did not allow for an assessment of its economic viability. The reverse osmosis unit would have only been economically viable, if the overall costs for water (including wastewater treatment) were greater than 52 ATS/m3. The brewery was currently serviced by the local authority waterworks, which charge a price of 33 A TS/m3 (for drinking water supply and wastewater treatment). The proposed water-saving recycling system could however be a financially viable solution for food processing plants, where water costs are considerably higher while the main parameters are very similar to those of the pilot scheme. Phase three could thus only be partly implemented and was limited to the drafting of the concept of the unit and a study assessing the financial viability of the project. As the current development indicates that drinking water is becoming more and more polluted, it is to be expected that this valuable resource will become more expensive in time so that the implementation of the proposed system could become an increasingly viable solution in the near future.
