title: Application of low-strength ultrasonication to the continuous anaerobic digestion processes: UASBr and dry digester.
abstract: In this study, the positive effects of low-strength ultrasonication (LS-ultrasonication) on the anaerobic digestion (AD) performance were investigated by continuously operating an upflow anaerobic sludge blanket reactor (UASBr) and a dry digester. In the ultrasonicated UASBr system (1 s per min, 0.05 W/mL), ultrasonication enhanced the CH₄ production by 38% and 19% in an ambient and a mesophilic condition, respectively. In addition, a different sludge yield and a changed electron flow were observed after ultrasonication. In the ultrasonicated dry digestion system (2 s per 30 s, 0.0025 W/mL), a 40% increase in the production of CH₄ was observed after lowering the total solid content of the reactor from 12% to 10%, implying that a high solid content diminished the ultrasonic stimulation effect. Moreover, the ultrasonication strength itself appeared to be a more crucial factor than the ultrasonication density during the application of LS-ultrasonication in the AD system.
authors.affiliation: Department of Civil and Environmental Engineering, KAIST, 373-1, Guseong-dong, Yuseong-gu, Daejeon, Republic of Korea.
authors.forename: Si-Kyung
authors.initials: SK
authors.lastname: Cho
authors.forename: Dong-Hoon
authors.initials: DH
authors.lastname: Kim
authors.forename: In-Seok
authors.initials: IS
authors.lastname: Jeong
authors.forename: Hang-Sik
authors.initials: HS
authors.lastname: Shin
authors.forename: Sae-Eun
authors.initials: SE
authors.lastname: Oh
mesh_terms: D001421:Bacteria, Anaerobic / Q000378:metabolism; D019149:Bioreactors; D005240:Feasibility Studies; D012722:Sewage / Q000737:chemistry*; D013010:Sonication / Q000379:methods; D014465:Ultrasonics / Q000379:methods
chemical_list: D012722:Sewage