Biostimulation to improve the dye biodegradation of organic dyes by activated sludge

In this work, biodegradation of organic pollutants by activated sludge (AS) in the presence of glucose (2 g/L) as an additional carbon source was studied. The AS (without pre-acclimation) was freely suspended under aerobic conditions. Three organic dyes representative of the Algerian textile industry were selected: Cibanon Navy (CN), Solophenyl Scarlet (SS) and Cibacron Green (CG). The results showed that after 10 days of incubation, AS displayed good biodegradation capabilities achieving removal percentages ranging from 50.3% to 89.4% and reduction in COD ranging from 93.1% to 98.3%. Particularly, the textile dye CN was removed up to 89% with high reduction in COD (94.7%). The microbial development stimulated by glucose achieved therefore efficiently the discoloration of contaminated solutions and pollutant degradation. Although it is assumed that dyes can be degraded only under anaerobic conditions, the wastewater treatment using AS appears therefore suitable to the removal of different types of textile dyes before final discharge.