Análise da fitotoxicidade de água residuária tratada de um frigorífico de suínos

Abstract

Currently, the concern with finite resources has been gaining prominence mainly in the slaughterhouse industry, which has a high consumption of water and then generates a significant demand for the treatment of generated wastewater. This study evaluated the phytotoxic effects of the wastewater after the biological and final treatment of a swine slaughterhouse in lettuce seed and determined the correlations between the physical­chemical characteristics of the effluent and the germination of the seed used as a bioindicator for the study of water quality. The physical­chemical parameters pH, turbidity, electrical conductivity, and sedimentable solids were characterized for both effluents and their phytotoxicity was determined through the number of germinated seeds (SG), germination index (GI), and root length (ICR). The effluent after the biological treatment obtained satisfactory results in the 20% solution, with adequate physical­chemical parameters. For the final effluent sample, a slight inhibition was indicated in the germination index (GI) at a concentration of 20%. However, it did not present a significant effect on seed development and relative growth of the radicle. About the physical­chemical standards, only the pH presented an adequate parameter, sedimentable solids, and turbidity obtained high values. Electrical conductivity presented high values in factor the addition of the coagulant based on ferric chloride. However, for long­term effects, it is necessary to evaluate with a longer time variable.