Enhanced solubilization and biochemical methane potential of waste activated sludge by combined free nitrous acid and potassium ferrate pretreatment.

Author(s) Wang, J.; Zhang, Z.; Ye, X.; Pan, X.; Lv, N.; Fang, H.; Chen, S.
Journal Bioresour Technol
Date Published 2020 Feb

The increasing production of waste activated sludge (WAS) from wastewater treatment plants presents an inherent environmental burden. In this study, Free nitrous acid combined with potassium ferrate (FNA + PF) pretreatment was used to enhance solubilization and biochemical methane potential of WAS. Results indicated that the maximum removal rates of total suspended solid by PF, FNA, and PF + FNA pretreatment were 21.84%, 38.09%, and 56.17%, respectively. The biochemical methane potential of WAS without pretreatment reached 61.22 L CH/kg VSS added while this value increased to 147.07 L CH/kg VSS added after FNA + PF pretreatment (0.06 g/g TSS NaNO and 0.25 g/g TSS KFeO). Shotgun metagenomic analysis revealed that FNA + PF pretreatment could increase the diversity and stability of microbial communities by shifting methanogenic pathways from strictly acetoclastic to acetoclastic/hydrogenotrophic, thereby enhancing methane production. This study suggested that FNA + PF pretreatment is a promising technology to reduce WAS and enhance methane production by pretreated WAS during anaerobic digestion.

DOI 10.1016/j.biortech.2019.122376
Keywords Anaerobiosis; Bioreactors; Iron Compounds; Methane; Nitrous Acid; Potassium Compounds; Sewage; Waste Disposal, Fluid
ISSN 1873-2976
Citation Bioresour Technol. 2020;297:122376.

Related Applications, Forms & Industries