Quality monitoring of reused water for intensive tilapia and shrimp culture in the semi-arid region

Abstract

The present study evaluated the physicochemical variables of reused water quality for tilapia (Oreochromis niloticus) and shrimp (Litopenaeus vannamei) cultivation using biofloc technology (BFT) in the semi-arid region. The water quality showed the best results using wheat, molasses, or cassava starch as a carbon source, with sugar cultivation being the one that presented the greatest obstacles. Although the control treatment is based on a system with water renewal, no attribute showed a significant difference from the other treatments. The ammonia concentration varied according to the days of cultivation; it can be stated that the BFT system was efficient in maintaining the water quality. Variations in ammonia, nitrite, nitrate, and phosphorus concentrations were direct responses to pH and temperature, in addition to conductivity interference. The other attributes were not selected by the models (p>0.05), indicating that the variation, within the observed values, did not alter the aforementioned concentrations, highlighting the efficiency of the biofloc system as an alternative for water reuse with low replacements. Thus, it can be concluded that it is possible to reuse water in crops with minimal replacement to mitigate environmental impacts as well as strengthen development in semi-arid regions.