Denitrification of Nitrate Wastewater Using Packed-Bed Columns

• Published in: Water environment research Vol. 76; no. 5; pp. 388 - 393
• Main Authors: Lee, Lai Yoke, Ong, Say Leong, Ng, Wun Jern
• Format: Journal Article
• Language: English
• Published: Alexandria, VA Water Environment Federation 01-09-2004; Blackwell Publishing Ltd
• Subjects: Acetates; Applied sciences; Atmospheric pollution; ATTACHED‐GROWTH SYSTEM; Biofilms; Biomass; Biomass production; Bioreactors; Chemical oxygen demand; DENITRIFICATION; Exact sciences and technology; Loading rate; Nitrate content; Nitrates; Nitrates - isolation & purification; Nitrogen; NITROGEN REMOVAL; Packed bed reactors; PACKED‐BED COLUMN; Pollution; Research Papers; SYNTHETIC NITRATE WASTEWATER; Waste Disposal, Fluid - methods; Wastewater; Water Pollutants - isolation & purification; Water Purification - methods; Water treatment; Packed bed; Chemical oxygen demand; Reaction order; Water quality; Fixed bed reactor; Specific surface area; Kinetics; Packed column; Waste water
• ISSN: 1061-4303; 1554-7531
• DOI: 10.2175/106143004X151653

Columnar packed-bed (PB) reactors with a specific surface area of 127${\rm m}^{2}/{\rm m}^{3}$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${\rm N}/{\rm m}^{2}\cdot {\rm d}$and 158.0 g${\rm COD}/{\rm m}^{2}\cdot {\rm d}$, respectively. The substrate removal rate in the PB column was found to follow half-order reaction kinetics, with a reaction coefficient, k, of 53.62$({\rm mg}/{\rm L})^{1/2}/{\rm d}$. 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${\rm NO}_{3}{}^{-}\text{-}{\rm N}/{\rm L}$and 50.0 mg COD/L, respectively, were obtained when the dual PB system was used.