title: Effects of carbon-nitrogen ratio on nitrogen removal in a sequencing batch reactor enhanced with low-intensity ultrasound.
abstract: A sequencing batch reactor (SBR) enhanced with low-intensity ultrasound was designed to study the removal of nitrogen under different carbon-nitrogen (C/N) ratios. The results showed that the removal efficiencies of CODCr and nitrogen were inversely proportional to C/N ratios. The CODCr of the effluent in the control reactor (CR) and the low-intensity ultrasound-enhanced reactor (UER) were lower than 40 mg L(-1). With a decrease in C/N ratio, the NH4(+)-N removal load of the CR showed little change, while the NH4(+)-N removal load of UER increased from 21.2 to 56.1mg NH4(+)-N/g mixed liquid suspended solids per day. To further understand effects of low-intensity ultrasound, the denaturing gel gradient electrophoresis (DGGE) analysis showed that the similar coefficients of the community structures in the UER and CR were 86%, 52% and 29% when the C/N ratios were 15:1, 10:1, 5:1, respectively.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian 116024, China. Electronic address: jruofei@dlut.edu.cn.
authors.forename: Ruofei
authors.initials: R
authors.lastname: Jin
authors.forename: Guangfei
authors.initials: G
authors.lastname: Liu
authors.forename: Chunling
authors.initials: C
authors.lastname: Li
authors.forename: Rongjuan
authors.initials: R
authors.lastname: Xu
authors.forename: Hongyang
authors.initials: H
authors.lastname: Li
authors.forename: Lunxiang
authors.initials: L
authors.lastname: Zhang
authors.forename: Jiti
authors.initials: J
authors.lastname: Zhou
mesh_terms: D061249:Batch Cell Culture Techniques / Q000295:instrumentation*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors / Q000382:microbiology*; D002244:Carbon / Q000494:pharmacology*; D058645:Denaturing Gradient Gel Electrophoresis; D064307:Microbiota / Q000187:drug effects; D009584:Nitrogen / Q000302:isolation & purification* / Q000494:pharmacology*; D014465:Ultrasonics; D014865:Waste Disposal, Fluid
chemical_list: D002244:Carbon; D009584:Nitrogen
keywords: C/N ratio; DGGE; Low-intensity ultrasound; Nitrogen removal; SBR