Quality and possible use of effluents from caiman farms

MELINA S. SIMONCINI; PAMELA ML LEIVA; MIGUEL FORNI; MARIA CARRIZO; ALEJANDRO LARRIERA; MARCELA GONZÁLEZ.; CARLOS I. PIÑA; SILVIA IMHOF

CHETUMAL

Congreso; XXV Working Meeting CSG-UICN; 2022

CSG

Caiman farms discard large volume of water and suspended solids (rest offood and feces). Those effluents most of the times are stocked in pools without anyuse. Our objective was to characterize chemical, physical and microbiological residualwaters of those lagoons (both at surface and bottom). The effluent presented lowcontent of dry mater and ashes at surface or bottom (0.13% on 0-60 cm and 0.17% ondeeper than 60 cm), nutrients were low, pH slightly alkaline, and electric conductivitywas a little bit lower than the critical value 2dS/m. Sodium (406.5 mg/L) and nitrogen(about 100 mg/L) were in high concentration, but phosphorus was very low (5.9 mg/L).Content of Ca, Mg, and K was 97.5, 25, and 107.5 mg/L, respectively, and increasedwith depth. Levels of BOD and COD indicated the water was slightly contaminated(20.6 mg O2/L) and under levels of industrial effluents (24.8 mg O2/L). Microbiologicalanalysis did not register Salmonella, but Escherichia coli was present, also we foundtotal anaerobics, and coliforms. Based on results a possible use is for agriculture,production of trees, or species used to feed livestock. For every option amount ofpathogens must be determinate and if they exceed regulated values they should bereduced.