Advanced Additive Strategies for Optimized Biogas Production from Anaerobic Digestion of Sludge: Insights into Biochar, Enzymes, Microbes, and Nanoparticles

Purpose: Anaerobic digestion (AD) of sludge is a widely applied process for organic waste treatment and renewable energy production. However, conventional AD often faces limitations such as slow hydrolysis, low methane yield, and inhibition from heavy metals or ammonia accumulation. Innovative additive strategies, including biochar, enzymes, microbial consortia, and conductive nanoparticles, have shown potential to enhance biogas production, accelerate substrate degradation, and improve process stability. This study aims to systematically review the effects of these additives on sludge AD, addressing knowledge gaps regarding their mechanisms and comparative effectiveness. Methods: Articles from the literature were reviewed to evaluate the impact of different additives on sludge AD performance. The review focused on methane yield, volatile solids reduction, microbial activity, and electron transfer efficiency Conclusion: The integration of targeted additives offers a promising approach to overcoming conventional limitations of sludge AD, resulting in higher biogas yields, improved process stability, and accelerated substrate conversion. These findings provide a foundation for optimizing additive selection and operational strategies in full-scale AD systems. Future research should focus on synergistic combinations of additives, economic feasibility, and environmental safety assessments to facilitate large-scale implementation.

کلیدواژه ها:

Anaerobic digestion ، Sludge ، Biochar ، Enzymatic pretreatment ، Microbial augmentation ، Nanoparticles