Decolourisation of reactive black 5 using Lysinibacillus fusiformis ZB 2

Abstract

The textile industries cause various problems related to the textile wastewater effluent, including that of discharge and treatment of dyes. The majority of the commonly used dyestuffs which accounted for nearly 50% of the dyes are azo dyes. In this research, the effects of three parameters including pH, temperature, and dye concentration were tested to optimise the decolourisation of azo dye Reactive Black 5 (RB 5) using pure culture of Lysinibacilus fusiformis ZB 2 in a sequential facultative anaerobic-aerobic condition. Glucose and yeast extract were used in the medium as co-substrates. The results achieved indicated that Reactive Black 5 decolourisation was most effective at pH 9, 37°C, and 100 ppm RB 5. Optimised decolourisation of 95.5% was achieved at 24 hours of the treatment process. In addition, the COD removal was 33.2% after 24 hours of incubation under the aerobic condition. In conclusion, Lysinibacillus fusiformis ZB 2 showed significant potential in decolourising the RB 5 and could be used as a candidate for biological treatment of coloured textile wastewater.