Biodegradation of organo-metallic pollutants in distillery wastewater employing a bioaugmentation process

The objective of this work was to study the potential of a constructed bacterial consortium (comprised three strains: Stenotrophomonas maltophilia, Bacillus cereus, and Bacillus anthracis) to treat distillery wastewater via the bioaugmentation process. The discharged wastewater showed elevated total ammonium nitrogen (195.0 ± 1.24 mg L⁻¹), total dissolved solids (25980.6 ± 8.09 mg L⁻¹), chemical oxygen demand (20534.5 ± 3.12 mg L⁻¹), and biological oxygen demand (20534.5 ± 3.12 mg L⁻¹). High concentration of heavy metals, phenolic and organo-metallic compounds were also detected. Results showed that growing the bacterial consortium in the distillery wastewater at 37 °C supplemented with 1% glucose achieved the best color reduction (up to 90%) in 144 h. The physico-chemical quality of the treated wastewater also improved by 50%–70%. Furthermore, many of the major organic pollutants present in the distillery wastewater were degraded by the constructed consortium to below detection limit via active biotransformation and biodegradation. Heavy metals were biosorbed by the bacterial consortium, and the ligninolytic enzymes such as Lip and MnP played an important role in the degradation of the organo-metallic pollutants. The constructed bacterial consortium therefore offered a sustainable and effective solution to treat distillery wastewater.