Evaluation of chemicals tools for Eutrophication management in a shallow pond in the Pampas, Argentina

BAUZA L; TELESE L; OLIVER C; GIANNUZZI L; ECHENIQUE R; ANDRINOLO D

Estambul

Congreso; VIII International Conference on Cyanobacteria; 2010

VIII International Conference on Cyanobacteria

Background and aims Water eutrophication has a deep impact on the development of toxigenic cyanobacteria blooms. The level of 50 ppb total phosphorus is proposed as a key in the formation of these blooms. The work aim was to evaluate, at laboratory and mesocosms scale, the use of chemical agents able of phosphorus sequestering, to mitigate eutrophics process with the minor environmental impact as possible. Methods The small body of water Laguna Los Patos, Buenos Aires, Argentina, near to a sanitary landfill (CEAMSE) was chosen to study. Laboratory tests were performed in 1L Erlenmeyer flasks and mesocosms in containers of 200L in bottomless containers. Different concentrations of aluminum-polychloride (PCA), aluminum sulfate and iron wires were tested. Total phosphorus, and chlorophyll-a were used as indicators of the degree of eutrophication by TSI (Trophic State Index) of Carlson. Soluble Phosphorus, COD, pH, turbidity, TDS and conductivity were considered to complement the water quality characterization. Results and conclusion. “Los Patos” has intense and permanent cyanobacterial blooms (Planktothrix agardhii, Anabaenopsis elenkinii and Anabaena aphanizomenoides), high concentrations of total phosphorus and alkaline pH, being defined as hypereutrophic by TSI. In mesocosms conditions, the PCA and the iron wires were able to decrease soluble phosphorus and pH, without major modification in the other components as COD and chlorophyll. PCA and iron wires could be tools for eutrophication control.