The impact of Covid-19 pandemic on water supplies and wastewater sewer system

Besides other issues, the global pandemic caused by SARS CoV-2 also brought a number of water management questions which mainly concern the likelihood of virus spread through drinking water and possible contamination of wastewater. This paper reviews principal data on the virus and the recent course of the pandemics. It shows that there is no risk of the virus spread through drinking water and that drinking water disinfection is sufficiently effective. On the contrary, wastewater was observed for SARS CoV-2 RNA particles. As a result, a number of papers deal with research in the observation of the virus in wastewater, which may become an early-warning tool before an epidemic develops. The monitoring of the virus in wastewaters may also enable researchers to predict the course of Covid-19 illness rates in the future.

A standardized method to measure the longitudinal UV emittance of low-pressure-lamps in dependence of water temperature

The high level of acceptance of ultraviolet (UV) irradiation for water disinfection in the past decade is due to the development of quality standards, especially for drinking water disinfection in Europe (Austrian Standards Institute, German Standards Institute). The central parts of a UV-disinfection device are the UV lamps. Despite their importance, their characterisation and quality assurance is far from being a matter of course and had not been regulated so far. This holds especially with regard to their temperature behaviour. The UV radiation (UVR) emittance of Mercury-Low-Pressure- and Amalgam-Low-Pressure-lamps (LP-lamps) depends on temperature. Each lamp type has its own optimal temperature where UVR emittance is highest. At lower or higher temperatures, UVR emittance is reduced. Additionally LP-lamps do not emit homogeneous along their length and this emission profile can change with temperature. In this paper, we present a standardized method to measure the UVR emittance of LP-lamps along the length in water in dependence of water temperature. This method has been included in the updated Austrian standard ÖNORM M 5873-1 (2020) and in the new release DIN 19294-1 (2020). With this method, the UVR emittance of LP-lamps can be characterized and different types of lamps can be compared.