SciELO - Scientific Electronic Library Online

 
vol.26 número4Análisis del comportamiento de los lixiviados generados en un vertedero de residuos sólidos municipales de la ciudad de la Habana índice de autoresíndice de assuntospesquisa de artigos
Home Pagelista alfabética de periódicos  

Serviços Personalizados

Journal

Artigo

Indicadores

Links relacionados

  • Não possue artigos similaresSimilares em SciELO

Compartilhar


Revista internacional de contaminación ambiental

versão impressa ISSN 0188-4999

Resumo

MENDEZ NOVELO, Roger Iván; SAN PEDRO CEDILLO, Liliana; CASTILLO BORGES, Elba René  e  VAZQUEZ BORGES, Elizabeth. Modeling of holding time of water biological samples. Rev. Int. Contam. Ambient [online]. 2010, vol.26, n.4, pp.327-335. ISSN 0188-4999.

According to standard analytical methodologies, in order preserve water samples for microbial determination, they must be maintained under 10 °C for a maximum period of 6 hours for non-drinking water and 30 hours for drinking water. Although there is not an explicit reference to the water organic content, the difference between recommended preservation times could be related with it. Therefore, water samples with low organic content can be preserved for longer periods than those with a higher content. Several samples of water with different organic content (domestic wastewaters, from slaughterhouses and poultry farms, and from shallow wells) were analyzed. Models were developed in order to determine indicator organisms in CFU/100 mL (total and faecal coliforms, and enterococcus) as a function of BOD5. The assessment was carried out 6 to 48 hours after sampling. It was found that high BOD5 concentration in water is not a decisive factor when indicator organisms in CFU/100 mL are to be estimated (there is not a significant difference between total or faecal coliforms, neither between enterococcus between 0 and 48 hours). Nevertheless, there is a significant difference between total coliforms in CFU/100 mL when determined at 0 and 6 hours. This contradicts the established in several analytical methods. Samples for faecal coliforms determination can be preserved up to 6 hours, but at 18 hours there is a significant difference for results obtained in CFU/100 mL. For enterococcus, there is no significant difference in preservation between 0 and 48 hours.

Palavras-chave : sample preservation; faecal coliforms; total coliforms; enterococcus; pathogen microorganisms; bacteria.

        · resumo em Espanhol     · texto em Espanhol

 

Creative Commons License Todo o conteúdo deste periódico, exceto onde está identificado, está licenciado sob uma Licença Creative Commons