Clarification of Effluents Industry Using Nb2O5

The effluent treatment from the packaging industry, particularly color removal, is strongly influenced by process interferences. High concentrations of dyes often make water reuse unfeasible. In this context, the present work aims to study the clarification of the dye used in the packaging industry by the photocatalytic process. Niobium was used as a catalyst, which was characterized by different techniques. Before verifying the catalytic activity in the industrial effluent, tests were performed with synthetic dye solutions. As a characterization result, it was possible to identify typical characteristics of the semiconductor. The results with the synthetic effluent indicated that the photocatalytic reaction was adequate for the decolorization of the solution. The optimized conditions indicated pH conditions without adjustments (4.2) and a catalyst concentration of 1.0 g L−1, obtaining a decolorization of 98%. Tests with industrial effluent revealed that the optimum conditions were also obtained with an unadjusted pH (6.2) and catalyst concentration of 6.0 g L−1, obtaining, however, 42% discoloration. This result highlights the influence of the organic load and other interfering factors such as additives. However, the process is promising in the clarification of the effluent, which possibly, with a 42% reduction in color, can be reused in the process generating water sustainability. A curve adjustment was proposed to determine the best conditions obtained for both synthetic and industrial effluents.