Avaliação da fitoxicidade de lodo de estação de tratamento de efluentes de indústria de pescado utilizando olerícolas como bioindicadores

Abstract

The industrial solid residue destination is one of the most important environmental problems due your contamination potential. In this context, this study was realized with the objective to evaluate the effects on the application of fish industry effluent treatment’s sludge in vegetable crops, through germination index – IG and the growing in a greenhouse. In the first experiment, were realized the phytotoxicity tests, using different plant species: Lettuce (Latuca sativa), arugula (Eruca sativus) and cucumber (Cucumis sativus). The cress seeds did not germinate in the 48 hours preconized time and do not was evaluated. The IG results for the lettuce, arugula and cucumber seeds were higher than found on the control, indicating stimulus to the germination of evaluated seeds. The physicochemical characterization and bioassays results with cucumber, lettuce and arugula were submitted to statistical correlation, aiming the identification of phytotoxicity probable causes. All the physicochemical parameters evaluated attended to the standards preconized by the environmental legislation of residue ground application. For the greenhouse, was realized an experimental outlining of randomized blocks with four repetitions, with a 5 liters vase, factorial scheme of 4x3x2. In the greenhouse test, lettuce and arugula were utilized, plant height, green and dry mass of the plant’s top section, root length, green and dry mass of the plant’s root. The lettuce do not showed statistical difference between the four treatments for the leafs number, leaf height, green and dry mass of the plant’s top section, but presented statistical difference for root length. For the Spearman’s correlation, conductivity, aluminum and cadmium were the parameters that presented a negative correlation for root length and green and dry mass.The arugula showed statistical difference between the four treatments for plant’s top section and roots for all evaluated parameters. For the Spearman’s correlation, molybdenum presented a negative correlation and phosphorus, conductivity, calcium, cooper, chromium, zinc, manganese and nickel presented a positive correlation.