Integrated Resource Recovery from Sludge for Synergizing Quorum Sensing and Interspecies Electron Transfer in...

Area of Science:

• Environmental Science
• Microbiology
• Materials Science

Background:

• Anaerobic granular sludge (AnGS) is crucial for organic wastewater treatment but faces challenges with methanogen resistance and electron transfer.
• Current quorum sensing (QS) strategies for AnGS regulation are hindered by the high cost of signaling molecules.

Purpose of the Study:

• To develop a cost-effective method for enhancing AnGS performance using waste-derived materials.
• To investigate the combined effects of QS and direct interspecies electron transfer (DIET) on AnGS stability and efficiency.

Main Methods:

• Synthesized a novel functional material (AHLs/EPS@BC) by loading N-acyl-homoserine lactones (AHLs) and extracellular polymeric substances (EPS) from waste AnGS onto biochar (BC).
• Evaluated the impact of AHLs/EPS@BC on AnGS acid shock resistance, chemical oxygen demand (COD) removal, and specific methanogenic activity (SMA).
• Conducted mechanistic studies to elucidate the roles of QS and DIET in the enhanced AnGS performance.

Main Results:

• AHLs/EPS@BC significantly improved AnGS acid shock resistance, restoring COD removal efficiency to 90.2-93.8%.
• Specific methanogenic activity (SMA) was maintained at 16.7-21.1 mL/(gVSS·h).
• The composite enhanced AnGS stability and function by integrating QS-mediated microbial community restructuring and EPS secretion with DIET via conductive biochar and microbial components.

Conclusions:

• The developed AHLs/EPS@BC material offers a sustainable approach to wastewater treatment by leveraging waste sludge components.
• In situ recovery and application of high-value components from waste sludge present significant environmental and economic benefits.
• This strategy provides a novel, sustainable regulatory method for AnGS in organic wastewater treatment.