Unsteady state flow and stagnation in distribution systems affect the biological stability of drinking water

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Manuel, CM (Author) Other; Nunes, OC (Author) FEUP; Melo, LF (Author) FEUP

Journal

Title: Biofouling

Vol. 26

Pages: 129-139

ISSN: 0892-7014

Publisher: Taylor & Francis

Indexing

ISI Web of Knowledge - 22 Citations

ISI Web of Science

Scopus - 32 Citations

Scientific classification

CORDIS: Natural sciences > Environmental science > Water science > Drinking water treatment

FOS: Natural sciences > Biological sciences

Other information

Authenticus ID: P-003-A8Q

DOI: 10.1080/08927010903383448

Abstract (EN): The effects of water stagnation and flushing on the biological stability of drinking water were studied by promoting the formation of biofilms under continuous flow (turbulent or laminar) and subsequently subjecting them to unsteady hydraulic situations. Independently of the flow regime under which the biofilm was formed, stagnation promoted bacterial accumulation, either in attached or suspended form, which were carried away in higher numbers when flow was re-started, thereby compromising its biological quality. In all cases, Betaproteobacteria was the dominant phylogenetic group, although Gamma and Alpha subclasses were also present. These results suggest that special attention should be given to the biological quality of drinking water where consumption is subjected to strongly variable demands such as in seasonal hotels, week-end houses or dental clinics after week-ends as abnormal changes may have occurred in the microbiological parameters. Moreover, this study showed that the cultivable bacterial numbers are not related to those of total bacteria and, thus, should not be the basis for the routine tests of bacteriological control in these systems.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11