Enhancing electron transfer in anaerobic process by supercapacitor materials: Polyaniline functionated activated...

Area of Science:

• Environmental Science and Engineering
• Biotechnology
• Materials Science

Background:

• Direct Interspecies Electron Transfer (DIET) is crucial for optimizing anaerobic digestion (AD) efficiency.
• Enhancing DIET requires effective electron mediators to facilitate microbial communication and metabolic processes.

Purpose of the Study:

• To synthesize and characterize polyaniline-functionalized activated carbon (AC-PANi) as a potential DIET enhancer.
• To evaluate the impact of AC-PANi on the performance of anaerobic digestion.
• To elucidate the mechanisms by which AC-PANi improves AD through enhanced DIET.

Main Methods:

• Chemical oxidative polymerization was used to prepare AC-PANi.
• AC-PANi was incorporated into an anaerobic digestion system.
• Key performance indicators such as Chemical Oxygen Demand (COD) removal and methane production were measured.
• Biochemical analyses were performed to assess microbial activity, including adenosine triphosphate (ATP) synthesis, extracellular enzyme secretion, cytochrome C (Cyt-C) levels, and coenzyme F420 content in methanogens.

Main Results:

• AC-PANi exhibited pseudo-capacitance and excellent charge transfer capabilities.
• The addition of AC-PANi led to an 18.6% increase in COD removal and a 35.3% increase in daily methane production rate.
• AC-PANi promoted ATP synthesis and the secretion of extracellular enzymes and Cyt-C.
• Coenzyme F420 content in methanogens increased by 60.9% with AC-PANi addition.

Conclusions:

• AC-PANi is an effective material for enhancing DIET in anaerobic digestion.
• The improved DIET facilitates microbial metabolism, leading to higher organic matter degradation and methane yield.
• This study presents a practical method for improving AD performance using functionalized carbon materials.