Variations in physical and chemical parameters and plankton community structure in a series of sewage-stabilization ponds
Por:
Nandini S.
Publicada:
1 ene 1999
Resumen:
Variations in physical and chemical parameters and plankton community structure from urban-based sewage stabilization ponds in Delhi (India) were recorded from summer to winter months of 1992-1993. The quantified physico-chemical variables were temperature, pH, dissolved oxygen, soluble reactive phosphorus, total phosphorus, nitrate-nitrogen and chlorophyll-a. A qualitative analysis of the phytoplankton in all the ponds was made. Among zooplankton, rotifers, cladocerans, and copepods were identified and quantified. Observations were taken every month concentrations of soluble reactive phosphorus, total phosphorus and nitrate-nitrogen ranged between 1.2-2.0 mg l-1, 2.0-3.5 mg l-1, and 0.075-0.30 mg l-1, respectively. Although there were no significant differences in the nutrient concentrations between any of the ponds, the ponds receiving the raw sewage first had undetectable levels of chlorophyll-a for a greater part of the sampling period. As the water passed through the series of ponds, the quality improved and finally supported high zooplankton densities. There were summer blooms of Euglena, Pandorina, Spirulina and Oscillatoria. The commonly found rotifer species were Brachionus calyciflorus, Hexarthra mira and Filinia longiseta. Cladocera and Copepoda were represented, almost exclusively, by Moina macrocopa and Mesocyclops thermocyclopoides respectively.
Filiaciones:
Nandini S.:
Department of Zoology, University of Delhi, Delhi 110 007, India
Limnología, Conservación y Mejoramiento del Ambiente, División de Investigación, Campus Iztacala, AP 314, Tlalnepantla, Estado de Mexico, Mexico
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