Monitoring the gradual biodegradation of dyes in a simulated textile effluent and development of a novel triple layered fixed bed reactor using a bacterium-yeast consortium

Abstract

Textile industry effluents contain a variety of dyes, which are normally resistant to biodegradation. A bacterial-yeast consortium (Brevibacillus laterosporus and Galactomyces geotrichum) was used for decolorization of two real textile effluents (RTE) and a simulated synthetic effluent (SSE). It showed enhanced decolorization compared to that of individual microorganisms with decolorization efficiency of 89, 60 and 69% for RTE-1, RTE-2 and SSE respectively, within 48 h. The cumulative action of oxido-reductive enzyme in the consortium was responsible for improved decolorization. Spectroscopic analysis suggested effective biodegradation of dyes present in the SSE by the consortium contrarily to the individual strains. The gradual biodegradation of each dye present in the SSE was monitored using high performance thin layer chromatography (HPTLC). The consortium biodegraded all of the dyes within 1 has compared to that of partial biodegradation by the individual microorganisms. A novel, triple layered fixed bed reactor was designed for continuous decolorization of effluent. It showed >80% decolorization (at 100 mL h(-1) flow-rate), for a period of 7 days, along with 78% reduction in COD. The reproducibility of the bioreactor could be maintained for three consecutive cycles (7 days each).