title: Denitrification of nitrate wastewater using packed-bed columns.
abstract: Columnar packed-bed (PB) reactors with a specific surface area of 127 m2/m3 were investigated in this study for treating nitrate wastewater. This study demonstrated that a single-stage packed bed was able to achieve total nitrogen (TN) and chemical oxygen demand (COD) removal efficiencies higher than 83 and 75%, respectively. The highest achievable TN and COD removal rates were 47.2 g N/m2 x d and 158.0 g COD/m2 x d, respectively. The substrate removal rate in the PB column was found to follow half-order reaction kinetics, with a reaction coefficient, kappa, of 53.62 (mg/L)1/2/d. A dual-stage PB system was capable of achieving TN and COD removal efficiencies greater than 99 and 98%, respectively. Effluent TN and COD concentrations less than 6.5 mg NO3(-)-N/L and 50.0 mg COD/L, respectively, were obtained when the dual PB system was used.
authors.affiliation: Centre for Water Research, Department of Civil Engineering, National University of Singapore. cveleely@nus.edu.sg
authors.forename: Lai Yoke
authors.initials: LY
authors.lastname: Lee
authors.forename: Say Leong
authors.initials: SL
authors.lastname: Ong
authors.forename: Wun Jern
authors.initials: WJ
authors.lastname: Ng
mesh_terms: D019149:Bioreactors; D009566:Nitrates / Q000302:isolation & purification*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014873:Water Pollutants / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods
chemical_list: D009566:Nitrates; D014873:Water Pollutants