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초록

This study investigated feedstock variation's impact on biohydrogen production, metabolic pathways, and microbial dynamics in a lab-scale dynamic membrane bioreactor (DMBR). The evaluation used a synthetic substrate simulating the sugar composition of dried food waste hydrolysate (DFWH). DMBR-R1 was fed a defined substrate before switching to DFWH at a 3-h hydraulic retention time (HRT), showing deterioration due to microbial adaptation challenges. DMBR-R2 was fed solely with DFWH using a 12 to 3-h HRT reduction. The reactor achieved a hydrogen production rate (HPR) of 25.4 +/- 1.9 L H2/L/d, hydrogen yield (HY) of 1.12 +/- 0.12 mol H2/ mol hexoseequivalent consumed, and 80.5% carbohydrate utilization efficiency. At a 13-16 kPa transmembrane pressure (TMP), HPR at a 3-h HRT was the highest reported using food waste hydrolysate. At a 12-h HRT, biohydrogen production was enhanced by lactic acid utilization, whereas at a 3-h HRT, Clostridium-dominated populations prevailed. At a 3-h HRT, 90% of the DMBR-R2 particles were 774 mu m 2.75 times larger than those in DMBR-R1 correlating with elevated dissolved calcium concentrations. Microbial analysis showed that lactic acidutilizing bacteria Megasphaera elsdenii (45.9%) and C. puniceum (18.3%) contributed to metabolic shifts at a 12-h HRT, whereas Clostridium species dominated at a 3-h HRT, with C. pasteurianum (84.3%) in DMBR-R1 and C. puniceum (50.5%) and C. pasteurianum (26.6%) in DMBR-R2. Techno-economic analysis showed DMBR-R2 at a 3-h HRT yielded a 20-year highest net present value of 7.72 million USD, 6.01 times higher than at a 6-h HRT. These results highlight the influence of substrate composition, microbial dynamics, and operational conditions on biohydrogen production, positioning DMBRs as a cost-effective waste-to-energy technology.