Potassium ferrate coupled with freezing method enhances methane production from sludge anaerobic digestion.

Jiawei Hu, Zhuo Li, Zhigen Wu, Wenquan Tao

Bioresource technology 2021 Jul

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This study proposed a novel sludge pretreatment technology by combining freezing with potassium ferrate (PF) for synergistically enhancing the methane yield from sludge anaerobic digestion. Experimental results showed that the methane production was promoted from 170.1 ± 5.6 to 223.8 ± 7.0 mL/g VSS (volatile suspended solids) when pretreated by freezing coupled with 0.05 g/g TSS (total suspended solids) PF, with 31.6% increase. Kinetic model analysis indicated that the methane production potential and hydrolysis rate of sludge after combined pretreatment were enhanced by 32.0% and 15.0%, respectively. Mechanism studies revealed that freezing coupled with PF pretreatment effectively disrupted both extracellular polymeric substances (EPS) and microbial cells in sludge, consequently resulted in violent sludge disintegration. All the microbes responsible for hydrolysis, acidification and methanogenesis were found to be enriched by co-treatment of freezing and PF. Moreover, the fecal coliform in pretreated sludge was largely inactivated after anaerobic digestion. Copyright © 2021 Elsevier Ltd. All rights reserved.

Citation

Jiawei Hu, Zhuo Li, Zhigen Wu, Wenquan Tao. Potassium ferrate coupled with freezing method enhances methane production from sludge anaerobic digestion. Bioresource technology. 2021 Jul;332:125112