Multicomponent nanoparticles as means to improve anaerobic digestion performance

Area of Science:

• Biotechnology
• Environmental Science
• Nanotechnology

Background:

• Trace metals like iron and nickel are crucial for enzymes in anaerobic digestion (AD).
• Nanoparticles offer a novel approach to delivering these essential trace elements for AD processes.

Purpose of the Study:

• To investigate the impact of Fe2O3-TiO2 and NiO-TiO2 nanoparticles on anaerobic digestion.
• To assess the effectiveness of these nanoparticles on various substrates, including cellulose and municipal biopulp.

Main Methods:

• Coating iron (Fe2O3) and nickel (NiO) onto titanium dioxide (TiO2) nanoparticles.
• Evaluating the performance of bare TiO2, Fe2O3-TiO2, and NiO-TiO2 in batch and continuous anaerobic digestion systems.
• Testing with simple substrates (cellulose, glucose, acetic acid, H2-CO2) and complex substrate (municipal biopulp).

Main Results:

• Fe2O3-TiO2 and NiO-TiO2 nanoparticles significantly increased cellulose hydrolysis rates, up to 58% with NiO-TiO2 at optimal dosage.
• Low concentrations of NiO-TiO2 enhanced accumulated methane production by up to 24%, likely by boosting enzymatic activity.
• NiO-TiO2 improved methane yield by 8% in both batch and continuous anaerobic digestion of biopulp.

Conclusions:

• TiO2-supported iron and nickel nanoparticles are effective catalysts for anaerobic digestion.
• Optimized nanoparticle dosages can enhance hydrolysis and methane production in AD processes.
• NiO-TiO2 shows particular promise for improving the anaerobic digestion of complex organic waste like biopulp.