Bioflocculation of Basic Dye onto Isolated Microbial Biopolymers

Abstract

Three purified biopolymers isolated from Bacillus velezensis (40B), Bacillus mojavensis (32A) and Pseudomonas (38A) strains were evaluated for dye decolourization as bioflocculants. The decolourization capacity of the three polymers was inspected using C.I 28 basic yellow dye as hazardous pollutant. The chemical compositions of these purified biopolymers were considered by HPLC and FTIR spectrum. The decolourization efficiency of the three purified biopolymers was determined using both real dye polluted wastewater (discharged from AKSA EGYPT acrylic fibres industry) and simulated synthetic wastewater. The maximum decolourization efficiencies of the purified biopolymers of the three studied strains (40B), (32A) and (38A) were 91, 89 and 88 %, respectively. The equilibrium of dye sorption process onto biopolymers was described using Langmuir isotherm equation. However, its kinetics follows the pseudo second order model. The thermodynamic examination investigated the exothermic and spontaneous nature of the decolourization process using the purified biopolymers.

Bioremediation of Reactive Dyes by Bacillus megaterium and Bacillus velezensis

“…Bacillus velezensis is known for its possession of azoreductases which are used to decolourise azo dyes of different molecular structures through enzymatic action 26,27 . It was also reported that B. velezensis contains a biopolymer that was isolated and used to decolourise azo dyes by bio-flocculation, with 91% efficiency 28 .…”