Ecotoxicological evaluation of waste water from nitrocellulose production.

The present study evaluated the toxic potential and physicochemical characteristics of waste water generated in nitrocellulose production, including effluents from delignification, bleaching, nitration and mixture (composed of these three effluents), from a plant in the Paraiba Valley, São Paulo, Brazil. The test organisms used for toxicity assays were Daphnia similis, Danio rerio, Escherichia coli, Pseudomonas putida and Pseudokircheneriella subcaptata. The results showed that the effluents analyzed present acute and chronic toxicity for the organisms tested. Nitration effluent was the least toxic, while delignification and bleaching effluents were the most toxic. The naturally occurring pollutants in wood fiber and cotton, like lignin, probably contributed to effluents toxicity, in addition to higher concentrations of total dissolved solids, which are in non-compliance with Brazilian legislation, conductivity, chemical oxygen demand and color. The discharge of nitrocellulose effluent into an aquatic environment should only occur after appropriate treatment, due to their toxic characteristics.