Use of Microbial Carriers in Anaerobic Digestion: Scientific and Research Aspects

The use of microbial carriers in anaerobic digestion (AD) has been recognised as a scientifically validated method to enhance microbial activity, process efficiency, and biogas production. Research focuses on natural and modified materials that support microbial colonisation, enzymatic activity, and process stability under varied conditions.

A promising approach is the silica/lignin system, combining the large surface area and inert nature of silica with the biochemically active components of lignin. This composite stimulates dehydrogenase activity and promotes microbial proliferation, increasing methane production during mesophilic digestion of sewage sludge.

Another effective carrier is the diatomaceous earth/peat (DEP) composite. Its porous structure and sorptive properties create favourable conditions for microbial consortia development, especially during digestion of food waste. DEP use results in enhanced enzymatic activity and stabilised process kinetics, even under fluctuating organic loads.

The chitosan/perlite (Ch/P) system offers a unique combination of biological functionality and structural support. Chitosan modulates microbial interactions and may reduce inhibitory effects, while perlite provides mechanical durability. This carrier improves substrate conversion efficiency and microbial retention.

Notably, next-generation sequencing (NGS) has played a crucial role in characterising microbial communities associated with these carriers. NGS revealed shifts in the abundance of key methanogenic and fermentative taxa, confirming the carriers’ influence on microbiome structure and function.

These findings highlight the importance of selecting appropriate microbial carriers to optimise AD processes. Continued research into such materials represents a vital step towards sustainable waste management and renewable energy production.