Development and performance of BAC-ZS bacterial consortium as biofilm onto macrocomposites for raw textile wastewater treatment

One of the most abundant dyes that are used extensively in the textile manufacturing are azo dyes, which may endanger water bodies since incomplete breakdown of dyes may cause mutagenic and carcinogenic compounds to persist. In this study, BAC-ZS, bacterial mixed culture consisting of three acclimatised decolourising bacteria were grown as biofilm onto macrocomposites. Different time duration between 3 to 14 days of biofilm development was studied to determine the density of biofilm attached onto macrocomposites. Sequencing batch reactors (SBRs) were set up for raw textile wastewater treatment to investigate the effectiveness of the treatment with and without the presence of biofilm (control). The treatment was performed under facultative anaerobic-aerobic condition for 20 days continuously with 48-hour of hydraulic retention time (HRT) cycle (consisting both conditions). Colour and chemical oxygen demand (COD) were monitored throughout the treatment process. Results showed that the colour and COD removal by the developed biofilm were 78.6 ± 1.4% and 76.4 ± 1.12% from initial values of 1400 ADMI and 660 mg/L, respectively while only 47.9 ± 0.9% colour and 38.0 ± 1.5% COD removal for the control. In conclusion, the biofilm of BAC-ZS mixed culture coated onto macrocomposites showed potential applications in the treatment of raw textile wastewater.