Pessoa Wanderley, CR; Andrade, MV; Pereira, LJ; Marinho Silva, GM; Pessoa, KR; ,
The mineralization of the azo dye congo red by the fungi Phanerochaete chrysosporium was studied in two sequential batch bioreactors (R1 and R2), operated in cycles of 48 h (step I) and 24 h (step II). In step I, glucose concentration was 1 g.L-1 in both reactors and in step IL 1 g.L-1 of glucose was maintained in R1, but R2 received no addition of glucose. In step I, the average dye removal efficiencies were 76 +/- 29 % (R1) and 53 +/- 15% (R2), while in step II the averages recorded for dye removal for R1 and R2 were 84 +/- 15 and 70 +/- 28%, respectively. The rates of dye removal were 0.04 h(-1) in R1 and 0.03 h(-1) in R2 in step I. Higher rates were obtained in step II, 0,07 h(-1) and 0,02 h(-1) for R1 and R2, respectively. The highest dye removal occurred in R1 and, in R2, the residual dye was further removed. Laccase was the oxidised at higher amount, in step I was 54 mu mol.min(-1) for R1 and 38 mu molmin(-1) for R2. The proposed treatment system was very effective in removing the azo dye, however the mineralization may not be complete and some by-products may have been formed, according to spectrofotomefric analysis, were the peak corresponding to benzene, 220 nm, persisted.