The aim of the project is to holistically and systematically investigate drinking water installations in the lab, in technical centres and in field trials. Specifically, to prove the effectiveness of ultrafiltration with regard to securing a hygienically safe operation in the event of reduced temperatures for domestic hot water as well as the primary energetic impact and the effects of CO2 emission reduction.
Based on the current accepted rules of engineering for drinking water hygiene reasons – targeted to Legionella spp. – industrial plants are required to maintain a temperature of 60 °C at the drinking water heater outlet and to operate the circulation system at 55 °C minimum. This temperature level makes it difficult to use regenerative heat generators and to implement low-tempered heat grids.
The targeted separation of microorganisms and nutrients appears to be a useful technical approach to enable operators to run drinking water heating systems with considerably reduced temperatures. Microorganisms can be separated out by using UF systems in the installation.
The outlined project aims to carry out a systematic, scientific investigation into the relationship between the concentration of microorganisms in the water and Legionella contamination in the system. This concerns not just the effect of the UF systems but also the safety and security of avoiding back contamination in the drinking water installation and the effectiveness of backwashing the filter and safely discharging the wash water.
The results of the project should be used to make scientifically based recommendations on the use of ultrafiltration in drinking water installations.