Coupling of biocarriers and dynamic membrane for an enhanced volatile fatty acids production from sludge anaerobic fermentation.

Efficiently and economically recovering volatile fatty acids (VFAs) from sludge anaerobic fermentation (AF) poses a significant challenge. This study discovered a synergistic enhancement effect on VFAs production and membrane fouling control by combining polyethylene (PE) biocarriers and dynamic membrane technology (DM) in an anaerobic bioreactor. The reduced sludge particle size and enhanced hydrolysis efficiency led to a VFAs yield of 1200 mg/L, which is 2.4 times higher than that of traditional AF processes and 1.7 times greater than using the DM module alone. The introduction of PE promoted the enrichment of hydrolytic bacteria, particularly the Christensenellaceae_R-7_group, and facilitated the biotransformation of organic matter. The frictional properties of PE significantly reduced DM fouling, maintaining the transmembrane pressure drop below 30 kPa throughout operation without the need for DM module replacement or cleaning. This study presents a novel approach for resource recovery from sludge through AF, offering new opportunities in the field.