Copper removal using a heavy-metal resistant microbial consortium in a fixed-bed reactor

Area of Science:

• Environmental Microbiology
• Bioremediation
• Water Treatment Technologies

Background:

• Heavy metal contamination, particularly copper, poses significant environmental risks.
• Microbial consortia from contaminated sites offer potential for bioremediation.
• Biofilm formation is crucial for microbial immobilization and bioreactor efficiency.

Purpose of the Study:

• To evaluate a heavy-metal resistant bacterial consortium for copper removal.
• To investigate the effects of copper on consortium biofilm formation.
• To design and test a fixed-bed bioreactor using the consortium for copper remediation.

Main Methods:

• Isolation of a heavy-metal resistant bacterial consortium from a contaminated river.
• Determination of copper sorption capacity using the Langmuir model.
• Confocal microscopy to assess copper's effect on biofilm formation.
• Construction and analysis of a fixed-bed bioreactor with biofilm-granular activated carbon (BGAC).

Main Results:

• The bacterial consortium exhibited a high copper sorption capacity of 450.0 mg/g dry cells, attributed to carboxyl and hydroxyl groups.
• Copper exposure reduced biofilm thickness by 57% but maintained 84% cell viability.
• The BGAC fixed-bed bioreactor retained 45% of influent copper, significantly outperforming GAC-only columns (17%).

Conclusions:

• Native microbial communities can be effectively utilized in bioreactors for heavy metal removal.
• Immobilized bacterial consortia show promise for treating copper-contaminated water.
• Fixed-bed bioreactors offer an efficient approach for bioremediation of metal-polluted aquatic environments.