Bioremediation of Textile Azo Dyes by an Aerobic Bacterial Consortium Using a Rotating Biological Contactor

Abstract

The degradation of an azo dye mixture by an aerobic bacterial consortium was studied in a rotating biological reactor. Laterite pebbles of particle size 850 microm to 1.44 mm were fixed on gramophone records using an epoxy resin on which the developed consortium was immobilized. Rate of degradation, BOD, biomass determination, enzymes involved, and fish bioassay were studied. The RBC has a high efficiency for dye degradation even at high dye concentrations (100 microg/mL) and high flow rate (36 L/h) at alkaline pH and salinity conditions normally encountered in the textile effluents. Bioassays (LD-50) using Thilapia fish in treated effluent showed that the percentage mortality was zero over a period of 96 h, whereas the mortality was 100% in untreated dye water within 26 h. Fish bioassay confirms that the effluent from RBC can be discharged safely to the environment.

Isolation, screening and development of local bacterial consortia with azo dyes decolourising capability

“…These results compared favourably with previous reported results showing 76% dye decolourisation in 3 days by mixed microbial consortium supplemented with cheap carbon and energy sources. All strains incubated in pure culture could reduce the colour of the dyes but the mixed culture did so more rapidly, suggesting some degree of synergism (Abraham et al, 2003). As with individual isolates, RR-11 and RBr-18 remained the most difficult dyes to be degraded; nevertheless the percentage of decolourisation was slightly higher than those of the individual isolates with 53% and 55% colour were removed respectively.…”

Toxic effects of chrysoidine on human serum albumin: isothermal titration calorimetry and spectroscopic investigations

“…However, some suppliers still use chrysoidine illegally to dye bean products and yellow croaker . Moreover, as it is widely used in the dye industry, the presence of chrysoidine in the water environment has become an problem due to the adverse impact not only for humans but also on the whole ecological system .…”

Bioreactors for Azo-Dye Conversion

“…Different methods can be used to establish the required anaerobic conditions. A common procedure is simply sparging oxygen-free gas (continued) [15,17,19,20,34]. It is often hypothesized that azo-dye conversion is still carried out under microaerophilic conditions that establish in the inner region of the biophase, in agreement with the findings of Zhang et al [5].…”