A recent study examined how varying particle sizes of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More influence anaerobic digestion (AD) of food waste under high organic loading rates (OLR). The researchers prepared four different biochar sizes (40-200 mesh) and tested their effects on methane production and microbial community structure in an AD system operating at 30 g volatile solids per liter (VS/L).

The biochar with a particle size of 102 μm (RBC-P140) showed the most significant impact, enhancing methane accumulation by 13.2%. Smaller biochar particles also improved the system’s tolerance to acidic conditions, which is crucial for stabilizing AD under high OLR. Microbial community analysis revealed that smaller biochar particles optimized the abundance of aceticlastic methanogens, essential for methane production, and improved the composition of zoogloea, a bacterial structure that aids in microbial aggregation.

While there was no direct correlation between biochar size and the system’s volatile acid or alkalinity levels, the results indicate that smaller biochar can improve system resilience to acid buildup. This study offers valuable insights into how biochar’s physical properties, especially particle size, can regulate and enhance AD systems, providing a theoretical foundation for improving methane production and system stability under challenging conditions.

These findings contribute to the broader understanding of biochar’s role in AD and its potential to increase energy recovery from food waste while reducing greenhouse gas emissions.