Research article2020Peer reviewedOpen access
Impact of UV irradiation at full scale on bacterial communities in drinking water
Pullerits, Kristjan; Ahlinder, Jon; Holmer, Linda; Salomonsson, Emelie; Ohrman, Caroline; Jacobsson, Karin; Dryselius, Rikard; Forsman, Mats; Paul, Catherine J.; Radstrom, Peter
Abstract
Water in a full-scale drinking water treatment plant was irradiated with ultraviolet (UV) doses of 250, 400, and 600 J/m(2), and the effect on bacterial communities investigated using 16s rRNA gene amplicon sequencing, heterotrophic plate counts (HPCs), coliform, and Escherichia coli counts. The bacteria in the irradiated water were also analyzed following storage for 6 days at 7 degrees C, to approximate the conditions in the distribution system. The log(10) reduction of HPCs at 400 J/m(2) was 0.43 +/- 0.12. Phylogenetic examination, including DESeq2 analysis, showed that Actinobacteria was more resistant to UV irradiation, whereas Bacteroidetes was sensitive to UV. Phylum Proteobacteria contained monophyletic groups that were either sensitive or resistant to UV exposure. The amplicon sequence variants (ASVs) resistant to UV irradiation had a greater average GC content than the ASVs sensitive to UV, at 55% +/- 1.7 (n = 19) and 49% +/- 2.5 (n = 16), respectively. Families Chitinophagaceae, Pelagibacteraceae, Holophagaceae, Methylophilaceae, and Cytophagaceae decreased linearly in relative abundance, with increasing UV dose (P < 0.05, Pearson's correlation). When irradiated water was stored, Chitinophagaceae, Comamonadaceae, and Flavobacteriaceae families decreased in relative abundance, whereas ACK-M1, Mycobacteriaceae, and Nitrosomonadaceae were increasing in relative abundance. This suggests that the impact of UV irradiation cannot only be considered directly after application but that this treatment step likely continues to influence microbial dynamics throughout the distribution system.
Published in
npj clean water
2020, Volume: 3, number: 1, article number: 11Publisher: NATURE PUBLISHING GROUP
Sustainable Development Goals
SDG6 Clean water and sanitation
UKÄ Subject classification
Water Treatment
Publication identifier
DOI: https://doi.org/10.1038/s41545-020-0057-7
Permanent link to this page (URI)
https://res.slu.se/id/publ/105152