Qualidade da água e reuso em experimentos aquícolas com tecnologia de biofloco

Abstract

The present study evaluated the reuse of water in four different experiments, where the first and second experiments were carried out with tilapia culture and third and fourth experiment with marine shrimp, respectively, with biofloc technology (BFT) in the raising and fattening stages of tilapia of the Nile (Oreochromis niloticus). Nursery and juvenile shrimp production (Litopenaeus vannamei). Water collection and analysis were carried outat the Laboratory of Experimentation with Aquatic Organisms at the facilities of the Federal Rural University of Pernambuco at the Serra Talhada Academic Unit in Serra Talhada, PE, Brazil. In the experiments with Nile tilapia were used 4 circular tanks ofglass fiber with capacity of 1000L with useful volume of 800L. In the experiments with marine shrimp, 4 circular polyethylene tanks with a capacity of 20L and a useful volume of 15L were used. Water quality was analyzed based on temperature, dissolved oxygen, pH, and salinity. For the water analysis, total ammonia, nitrite, nitrate, alkalinity and total suspended solids were also monitored. The data were statistically analyzed at a significance level of 5%. All the physical-chemical variables presented significant difference after their reuse, with the exception of ammonia. The reuse of the water presented chemical modifications throughout its uses. However, it can be concluded that it is possible to re-use it in other crops with very small replenishments, provided that there is adequate monitoring and management throughout the crop so that the physicochemical and biological variables of the water remain in line with that recommended for the species.