Use of Phanerochaete Chrysosporium in a Semibatch Reactor for Removal of Indigo Carmine from Synthetic Textile Wastewater

Abstract The textile industry demonstrates a polluting potential from the planting of cotton to the release of wastewater. The presence of dyes in water bodies decreases the passage of sun rays and directly affects the photosynthetic organisms and the ecosystem. Fungi have potential in the treatment of wastewater containing dyes with complex organic structures due to enzymes that they produce. This study evaluated the use of Phanerochaete chrisosporium in the treatment of synthetic effluent from textile industry containing indigo carmine (20 mg/L). The fungus was immobilized in a semibatch reactor. Glucose was the cosubstrate employed in the experiment and it was used in the system at 1g/L at the beginning of the process and 0.5 g /L after 24 hours of reaction. Average dye removal was 84±10% and chemical oxygen demand removal was 79±14%. For nitrogen compounds, the removal efficiencies were 87±11%, 81±11% and 91±9% for ammonia, nitrite and nitrate, respectively. The pH of the medium remained in the acidic range (2.57 to 5.00) throughout the process, with the lowest values recorded in the effluent of each cycle, justified by the release of organic acids from fungi metabolism. There was contamination of the medium by bacteria (710,000 CFU/mL), but the colonies count showed a predominance of fungi (1,365,000 CFU/mL). With the use of the semibatch system after reading of glucose it was observed that the efficiency of dye removal evolved from 72±17% to 84±10%, producing a final effluent with 3.35±1.99 mg/L of indigo, which proves that treatment configuration analyzed is satisfactory for dye removal.

Azo Dye Mineralization by Phanerochaete Chysosporium in a Sequencing Bath Reactor

ABSTRACT 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 II, 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 μmol.min-1 for R1 and 38 μmolmin-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 spectrofotometric analysis, were the peak corresponding to benzene, 220 nm, persisted.