title: Influence of wastewater composition on biological nutrient removal in UniFed SBR process.
abstract: The effects of influent C/N ratio and C/P ratio on biological nutrient removal performance were investigated in a lab-scale UniFed SBR apparatus treating real domestic wastewater. The results showed that TN removal efficiency increased as C/N ratio increased from 43.6% at 2.8 to 80.8% at 5.7. But when C/N ratio increased further, TN removal efficiency increased very slowly. This was because when C/N ratio was higher than 5.7, complete denitrification in the sludge blanket during feed/decant period had been achieved, TN removal efficiency during this period always kept the maximum value and only TN removal efficiency during aeration period rose as C/N ratio increased. PO(4) (3-) removal efficiency increased as C/N ratio increased from 27.3% at 2.8 to 88.1% at 5.7. When C/N ratio was 6.5 and above, PO(4) (3-) concentration couldn't be detected in the effluent. When influent C/N ratio and volumetric exchange ratio were fixed at 6 and 33% respectively, as C/P ratio was higher than 33, PO(4) (3-) concentration of effluent always remained below the detection level and phosphorus removal efficiency kept stable at 100%, but as the C/P ratio was lower than 33, phosphorus removal efficiency increased as C/P ratio increased linearly. C/P ratio hardly affected TN removal efficiency, which always kept at 82.2%-85.8% in this study.
authors.affiliation: Key laboratory of Beijing Water Environment Recovery, Beijing University of Technology, Chaoyang District, Beijing, People's Republic of China. zhaochenhong@emails.bjut.edu.cn
authors.forename: C H
authors.initials: CH
authors.lastname: Zhao
authors.forename: Y Z
authors.initials: YZ
authors.lastname: Peng
authors.forename: S Y
authors.initials: SY
authors.lastname: Wang
authors.forename: X G
authors.initials: XG
authors.lastname: Tang
mesh_terms: D019149:Bioreactors; D002244:Carbon / Q000302:isolation & purification / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism; D010758:Phosphorus / Q000302:isolation & purification / Q000378:metabolism; D015203:Reproducibility of Results; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods*
chemical_list: D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen