Simultaneous analysis of the removal of brilliant blue and Red 40 through spectrophotometric derivative

Abstract

Effluents from food and textile industries contain dye mixtures. However, the evaluation of these multicomponent systems has been poorly explored due to their complex quantification. As a closer approximation to the contamination caused by these effluents, it was evaluated the adsorption of the dye mixture Red 40 (R40) and Brilliant blue (AB) on the coconut bark under batch system, considering the variables pH, the initial dye concentration, the dosage of the adsorbent and the temperature. For the quantification the model of the first derivative was used, using an UV-Vis Perkin Elmer Lambda 35 spectrophotometer. Under the best conditions for the mixture of R40 and AB, the maximum removal (76.5 %) was achieved to acid pH (pH = 2.0), dosage of 20 g/L, initial dye concentration of 10 mg/L and temperature of 55 °C. The found average percentage error for the model of quantification was 1.35 % for R40 and 1.10 % for AB to indicate the validity of the method. Also, in the binary mixture AB experimented a minor antagonistic effect due to the presence of R40, recording a 3.7 adsorption percentage higher than the obtained for R40.