The action of chemical and mechanical stresses on single and dual species biofilm removal of drinking water bacteria

• Tipo: Artigo em Revista Científica Internacional
• Data: 2018

Autores

Inês Gomes (Autor) FEUP; Madalena Lemos (Autor) Outra; L. Mathieu (Autor) Outra; Lúcia Simões (Autor) FEUP; Manuel Simões (Autor) FEUP

Revista

Título: Science of the Total Environment

Vol. 631-632

Páginas: 987-993

ISSN: 0048-9697

Editora: Elsevier

Indexação

ISI Web of Science

Scopus

Projetos Associados

LEPABE - Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia

LEPABE-2-ECO-INNOVATION - LEPABE-2-ECO-INNOVATION

Outras Informações

DOI: 10.1016/j.scitotenv.2018.03.042

Abstract (EN): The presence of biofilms in drinking water distribution systems (DWDS) is a global public health concern as they can harbor pathogenic microorganisms. Sodium hypochlorite (NaOCl) is the most commonly used disinfectant for microbial growth control in DWDS. However, its effect on biofilm removal is still unclear. This work aims to evaluate the effects of the combination of chemical (NaOCl) and mechanical stresses on the removal of single and dual species biofilms of two bacteria isolated from DWDS and considered opportunistic, Acinectobacter calcoaceticus and Stenotrophomonas maltophilia. A rotating cylinder reactor was successfully used for the first time in drinking water biofilm studies with polyvinyl chloride as substratum. The single and dual species biofilms presented different characteristics in terms of metabolic activity, mass, density, thickness and content of proteins and polysaccharides. Their complete removal was not achieved even when a high NaOCl concentrations and an increasing series of shear stresses (from 2 to 23 Pa) were applied. In general, NaOCl pre-treatment did not improve the impact of mechanical stress on biofilm removal. Dual species biofilms were colonized mostly by S. maltophilia and were more susceptible to chemical and mechanical stresses than these single species. The most efficient treatment (93% biofilm removal) was the combination of NaOCl at 175 mg·l−1 with mechanical stress against dual species biofilms. Of concern was the high tolerance of S. maltophilia to chemical and mechanical stresses in both single and dual species biofilms. The overall results demonstrate the inefficacy of NaOCl on biofilm removal even when combined with high shear stresses.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7