Evaluation of the Sensitivity of Freshwater Organisms Used in Toxicity Tests of Wastewater from Explosives Company

Explosives industries are a source of toxic discharge. The aim of this study was to compare organisms sensitivity (Daphnia similis, Danio rerio, Escherichia coli and Pseudomonas putida) in detecting acute toxicity in wastewater from two explosives, 2,4,6-TNT (TNT) and nitrocellulose. The samples were collected from an explosives company in the Paraiba Valley, So Paulo, Brazil. The effluents from TNT and nitrocellulose production were very toxic for tested organisms. Statistical tests indicated that D. similis and D. rerio were the most sensitive organisms for toxicity detection in effluents from 2,4,6-TNT and nitrocellulose production. The P. putida bacteria was the organism considered the least sensitive in indicating toxicity in effluents from nitrocellulose.

Ecotoxicological evaluation of wastewater from 2.4.6-TNT production

During the manufacture of explosives, large amounts of water are used to remove unwanted by-products generated. This water in turn, ends up in wastewater treatment plants or water bodies. The aim of this study was to evaluate the toxic potential of effluent generated by 2.4.6-Trinitrotoluene (TNT) production, yellow water, red water and mixture of yellow and red water, produced from a plant located in the Paraiba Valley, Sao Paolo state, Brazil. Daphnia similis, Danio rerio, Escherichia coli, Pseudomonas putida and Pseudokircheneriella subcaptata were used as test organisms. Physicochemical parameters such as color, pH, conductivity, total dissolved solids, dissolved oxygen, chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were evaluated. Effluent from 2.4.6-TNT production was extremely toxic to all test organisms. The physicochemical parameters evaluated showed high levels of conductivity (from 41.533 to 42.344 mu S /cm) and chemical oxygen demand (COD of 8471 to 27.364 mg/L) for the effluents analyzed.