Treatment stage associated changes in cellular and molecular microbial markers during the production of drinking water at the Vansjø water works

Abstract

The production of a drinking water that meets current aesthetic, microbiological and chemical standards, generally requires a combination of mechanical purification and disinfection in a multi-component treatment chain. Treatment choices and optimisation of water processing is best informed by using markers (including microbiological parameters) which indicate how each stage contributes to the production of the potable water. The present study combines culture-based and a number of culture-independent analyses to indicate what is happening at each stage of a state-of-the-art water treatment chain at Vansjø near the city of Moss in Norway. We show that particularly clarification with flotation and post-chlorination have profound and positive effects on water quality with respect to the removal and inactivation of microbes. Post-chlorination achieved better disinfection of the water than UV-treatment and was of paramount importance, as the penultimate step filtration through granular activated shed microbes to the water. Cloning and sequencing showed that some clones present in the raw water were detected at all stages in the treatment process, perhaps providing examples of microbes breaching physically all barriers in the treatment process. Results from the study should be useful in the improvement and maintenance of the treatment process at the Vansjø plant and others.

Centralized Drinking Water Treatment Operations Shape Bacterial and Fungal Community Structure

“…The culture analysis showed a similar decreasing trend through the treatment process train for both heterotrophic plate count and filamentous fungi colony counts (Table ). Both the qPCR and subsequent culturing results suggest the treatment process significantly reduced bacterial and fungal abundance, agreeing with previous culture-based studies. , …”

“…Both the qPCR and subsequent culturing results suggest the treatment process significantly reduced bacterial and fungal abundance, agreeing with previous culture-based studies. 41,42 As the eukaryote Acanthamoeba spp. is an important human pathogen 43 and may host other opportunistic pathogens such as Legionella spp., 44,45 qPCR was conducted to evaluate the presence and abundance of Acanthamoeba spp.…”