Mitigação dos impactos ambientais por meio da reutilização da água da aquicultura para irrigação no semiárido

Abstract

The present study was developed with the aim of investigating alternatives for water reuse in the semiarid region of Pernambuco, regions with limited water availability and low environmental impact. It is essential to develop studies that investigate the influence of nutrients, organic matter, water quality and their applications. The reuse of fish farming water (FFW) in an integrated farming system appears to be a viable and advantageous alternative. The application of FFW was tested at different carbon concentrations (0.0 to 100 mg C L-1) in agronomic trials using Solanum lycopersicum (cherry tomato). The germination rate (%G= 88%), presented higher values in FFW concentrations of 25.0 mg C L-1 (p<0.05), in addition to a better development, reaching from 5 to 6 cm. The tests showed that despite the variables being independent, concentrations from 5 mg C L-1 have already shown satisfactory results, highlighting the wide possibility of applying FFW. Another alternative to aquaculture water can also be biofloc technology with low water replenishment in crops. A study was carried out with three experiments that took place in 2014, 2015 and 2017 in order to monitor water quality in eutrophic environments. The study was carried out with experimental cultivations of tilapia (Oreochromis niloticus) and shrimp (Litopenaeus vannamei) using biofloc technology (BFT). The physicochemical attributes analyzed were: temperature, dissolved oxygen, pH and salinity. The results of water quality values using different carbon sources (sugar, molasses, cassava starch, wheat and the control for BFT) indicate that water quality monitoring achieved the best results using wheat and molasses as a source of carbon. However, it can be concluded that it is possible to keep crops in the semi-arid region of Pernambuco even having to deal with seasonality. These alternatives are capable of adding value to yet another source of income for family farming: be it through the integrated farming-fish farming system or through aquaculture using biofloc technology. The two alternatives studied reuse the effluents that would previously be released into water bodies, generating an environmental impact.