Portal de Periódicos da CAPES

Avaliação temporal do fitoplâncton na lagoa de polimento de uma estação de tratamento de esgoto

2009; Volume: 5; Issue: 1 Linguagem: Inglês

10.5008/1809.7367.021

2316-7327

Alessandra Delazari Barroso, Fabrícia Fafá de Oliveira, Maria Alice Moreno Marques, Samantha Miranda dos Santos, Fernanda Brêda, Carlos Alberto Baldotto Perim,

Water Quality and Pollution Assessment

This study is a subproject of the Project “Restoring life quality of a rural community: Caxixe watershed, Espírito Santo State, Brazil”. One of the goals is the assessment of the water resources that supply the Dordenone Village at Venda Nova do Imigrante, Espírito Santo State. It also aims at assessing the efficiency of the Integrated Biosystems Wastewater Treatment Plant (IBWTP). This paper presents the results of phytoplankton community in the polishing pond, which is one of the IBWTP stages. Monthly water samples were taken at subsurface from November 2007 to January 2008, with a 20 μm-mesh size plankton net. The variables water temperature, pH and dissolved oxygen were measured in situ. Thirty-seven phytoplankton taxa were found, belonging to the Chlorophyceae, Cyanophyceae, Euglenophyceae, Bacillariophyceae and Zignemaphyceae classes , whit qualitative and quantitative predominance of chlorophytes and cyanobacteria. The higher microalgae density was registered on March 2008 (5.6 x 105 ind/mL), associated with the higher water temperature and precipitation. The predominance of chlorophytes indicates that the polishing pond is suitable for fish farming. However, the occurrence of four cyanobacteria genera already registered as toxic in other states of Brazil reflects the potential of contamination by cyanotoxins, in the case of water use for fish farming.