Publicado 6 números por año
ISSN Imprimir: 0018-8166
ISSN En Línea: 1943-5991
Indexed in
Evaluation of the Ecological Integrity and Microalgae Carbon Sequestration Potential Across the Sewage Effluent Gradient of Tropical Waste Stabilization Pond System
SINOPSIS
Ecological integrity, that is spatial and seasonal variability of microalgae abundance and diversity, counts of biogeochemical cycle bacteria and carbon sequestration potential of microalgae, was studied in six waste stabilization ponds, used for treatment of the municipal waste waters and fish culture. The values of Shannon diversity index for Myxophycaeae, Euglenophyceae and Chrysophyceae were higher in facultative pond compared to maturation or fish ponds. The gross and net primary productivity of phytoplankton ranged respectively from 3.594 to 32.858 g C/m-2 · d-1 and 2.34 to 15.227 g C/m-2 · d-1. The P/R ratio in different ponds varied from 1.365 to 5.729. The nutrient cycling bacteria (heterotrophic, ammonifying, ammonia-oxidizing, cellulose decomposing and phosphate solubilizing) occurring in surface and bottom water layers tended to reduce in numbers from facultative to the last maturation or fish pond. The sum of total scores for different optimal conditions for fish growth also increased spatially exhibiting two clear cut zones: the facultative pond with dominance of blue green algae with greater carbon sequestration potential and the maturation or fish ponds developed a favourable environment for fish culture, mediated through microalgae-zooplankton grazing and microbial detritus food chain.