title: Performance of a full-scale biofilm system retrofitted with an upflow multilayer bioreactor as a preanoxic reactor for advanced wastewater treatment.
abstract: To enhance nitrogen removal in an existing microbial contact oxidation (MCO) system with a treatment capacity of 900 m3/d, an upflow multilayer bioreactor (UMBR) was chosen as a preanoxic reactor for the removal of organic matter and nitrate. The removal performance of the retrofitted plant was evaluated during the startup phase at a low temperature in winter. The high removal (>80%) of organic matter and suspended solids in the UMBR provided stable nitrification conditions in the MCO system, as a result of the substantial reduction in organic matter and solids loaded onto the MCO system. This treatment system showed a stable nitrogen removal efficiency of 75.3%, even in the low temperature range 7 to 10 degrees C. Phosphorus was completely removed by chemical precipitation. Production rates of excess sludge, as a function of the loads of influent flowrate and biological oxygen demand (BOD), were 0.022 kg dry solid/m3 wastewater and 0.132 kg dry solid/kg BOD.
authors.affiliation: Department of Chemical Engineering, Sungkyunkwan University, Suwon, Korea.
authors.forename: Jin-Young
authors.initials: JY
authors.lastname: An
authors.forename: Joong-Chun
authors.initials: JC
authors.lastname: Kwon
authors.forename: Deog-Won
authors.initials: DW
authors.lastname: Ahn
authors.forename: Hang-Sik
authors.initials: HS
authors.lastname: Shin
authors.forename: Sung-Ho
authors.initials: SH
authors.lastname: Won
authors.forename: Byung-Woo
authors.initials: BW
authors.lastname: Kim