Denitrification of nitrate wastewater using packed-bed columns.
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.
Lee
Lai Yoke
LY
Centre for Water Research, Department of Civil Engineering, National University of Singapore. cveleely@nus.edu.sg
Ong
Say Leong
SL
Ng
Wun Jern
WJ
D019149:Bioreactors; D009566:Nitrates / Q000302:isolation & purification*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014873:Water Pollutants / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods
D009566:Nitrates; D014873:Water Pollutants