Anaerobic fermentation of cheese by-product and sewage sludge for the volatile fatty acids (VFA) production and hydrogen accumulation

Abstract

The pursuit of sustainable waste management and renewable energy solutions has fueled an exploration of anaerobic fermentation as a pivotal process. In this study, mesophilic and thermophilic batch experiments were conducted to unravel the dynamics of anaerobic fermentation using cheese by-product (CbP) and sewage sludge (SS) substrates. Also, this study presents a comprehensive exploration of anaerobic fermentation dynamics in thermophilic condition through a reactor experiment. The experiment employed sludge and sludge-zeolite substrates. The introduction of zeolite into each sample was examined for its impact on the function of the samples like increasing amount of volatile fatty acid (VFA) accumulation. Remarkably, the mesophilic experiments showcased superior functionality of CbP over SS, with zeolite augmentation yielding positive outcomes. Additionally, the co-fermentation of SS and CbP proved synergistic, establishing substrate composition as a critical determinant of efficiency. Transitioning to thermophilic conditions, similar trends were observed, albeit with amplified results. The heightened metabolic activity under elevated temperatures led to increased VFA quantities. These findings underscore the potential for enhanced anaerobic digestion in both temperature ranges, reaffirming the role of substrate composition and temperature in optimizing this eco-friendly waste-to-energy process.