Biological Nitrogen Removal Database

A manually curated data resource for microbial nitrogen removal


Water Treatment Plant


Experimental setup


Influent:Wastewater

Denitrification system:Heterotrophic denitrification

Denitrifying reactor:Packed-bed

Medium:Ceramic beads

Culture taken from:Anaerobic sludge

Organism (s) cultured:nan

Respiration:Anaerobic

Electron donor:Methanol

Electron acceptor:Nitrate


Experimental Information


Input NO3-N (mg/l):1200

Nitrate removal rate (mg NO3-N/l/h):nan

Denitrification rate (gNO3-N removed/m3/day):nan

Microorganisms identified:nan

Molecular tools:nan


Information about Article


Major findings:Methanol was used as alkalinity source to control the pH, in autotrophic denitrification of synthetic wastewater with varying alkalinity to NO3 /N ratios.

Authors:Kim et al., 2002

Title:Monitoring the Denitrification of Wastewater Containing High Concentrations of Nitrate With Methanol in a Sulfur-Packed Reactor

Pubmed link:Link

Full research link:Link

Abstract:Biological denitrification of high nitrate-containing wastewater was examined in a sulfur-packed column using a smaller amount of methanol than required stoichiometrically for heterotrophic denitrification. In the absence of methanol, the observed nitrate removal efficiency was only about 40%, and remained at 400 mg NO(3)(-)-N/l, which was due to an alkalinity deficiency of the pH buffer and of CO(2) as a carbon source. Complete denitrification was achieved by adding approximately 1.4 g methanol/g nitrate-nitrogen (NO(3)(-)-N) to a sulfur-packed reactor. As the methanol concentration increased, the overall nitrate removal efficiency increased. As influent methanol concentrations increased from 285 to 570, 855, and 1,140 mg/l, the value of Delta mg alkalinity as CaCO(3) consumed/Delta mg NO(3)(-)-N removed increased from -1.94 to -0.84, 0.24, and 0.96, and Delta mg SO(4)(2-) produced/Delta mg NO(3)(-)-N removed decreased from 4.42 to 3.57, 2.58, and 1.26, respectively. These results imply the co-occurrence of simultaneous autotrophic and heterotrophic denitrification. Sulfur-utilizing autotrophic denitrification in the presence of a small amount of methanol is very effective at decreasing both sulfate production and alkalinity consumption. Most of methanol added was removed completely in the effluent. A small amount of nitrite accumulated in the mixotrophic column, which was less than 20 mg NO(2)(-) -N/l, while under heterotrophic denitrification conditions, nitrite accumulated steadily and increased to 60 mg NO(2)(-) -N/l with increasing column height.