EFFECT OF AERATION AND DIFFERENT CONCENTRATIONS OF CALCIUM SILICATE AS LIMING MATERIAL IN WATER QUALITY

Slag is the molten byproduct of many metallurgical operations, that is found throughout the world on a large scale and calcium silicates are present in steel slag. Since calcium metasilicate is an alternative to conventional liming fish products the aim of study was check the effect of aeration and calcium metasilicate concentrations in water quality. The experiment was care out during 60 days, in 24 aquariums (18 L), in laboratory of EW Shell Fisheries Center, Auburn University in Auburn AL, USA. Distinct concentrations of calcium silicate were tested (0.0, 0.1, 0.25 and 0.4 g/L) in combination with two aeration levels, with (164 ml/min; water residence time 109.16) and without aeration. Once a week were measured, alkalinity, hardness, calcium, sílicate, pH, conductivity, temperature and oxygen. It has been found that neutralization capacity increased with the concentration of the silicate and aeration. Aeration increased buffering capacity, providing similar results to those observed in aquaria without aeration with a higher concentration of silicate immediately above.

Acknowledgements: Capes, CNPq, FAPEMIG and BNB.