Avaliação do potencial de Jatropha curcas na degradação de corantes têxteis

Abstract

In 2011, the textile and clothing industries, together, were already the fourth largest economic activity in the world, concentrating 5.7% of manufacturing production and more than 14% of world employment. In this industry, Brazil stands out as one of the largest textile and clothing producers in Latin America and the world. The enormous importance of this sector, however, eventually leads to certain environmental problems. Most of the textile finishing operations use large quantities of water and chemical reagents, generating wastewater with several contaminants in its composition, among which we have several textile dyes, especially from the azo family. The presence of such dyes causes several problems, among which we can mention the reduction of the penetration capacity of sunlight in the water as well as a decrease in the quality of this for consumption, besides the possibility of many degradation for carcinogenic compounds. Among the environmentally friendly solutions to the problem we have bioremediation, especially phytoremediation. The focus of this work was the use of Jatropha curcas in the treatment of textile effluents contaminated with azo dyes. Jatropha curcas was chosen because it is a plant very resistant to biotic and abiotic stresses and already commonly used in other bioremediation programs. To verify the contribution of the plant in dye discoloration, seedlings that were submitted to the contact with the stains Astrazon Red, Astrazon Yellow Gold, Levafix Orange E-3GA and Remazol Blue RGB in the concentration of 20 mg/L in Hoagland nutrient solution. During the 15 days, the absorbances were reduced and at the end the plants were collected to weight the fresh mass and obtained the crude extracts to perform enzymatic activities. Solutions in contact with the plant were also collected for toxicity tests on Artemia salina. In the end, it was verified that the highest rates of effective discoloration were for the Astrazon Red and Levafix Orange dyes. In the enzymatic tests varied results were obtained, being possible to verify a greater activity of the enzyme peroxidase in the foliar and root tissues. Toxicity tests with Artemia salina indicated a reduction in toxicity of solutions treated with Jatropha curcas.