ESTIMATION OF ACTIVE NITROSOMONAS AND NITROBACTER CONCENTRATIONS IN ACTIVATED SLUDGE USING NITROGENOUS OXYGEN UPTAKE RATE

Kim, Sun-Jip

doi:2004.9.3.130

Environmental Engineering Research 2004;9(3): 130-142. DOI: https://doi.org/10.4491/eer.2004.9.3.130

ESTIMATION OF ACTIVE NITROSOMONAS AND NITROBACTER CONCENTRATIONS IN ACTIVATED SLUDGE USING NITROGENOUS OXYGEN UPTAKE RATE

Sun-Jip Kim^†

Mirae G&C Co., Ltd, Junhyun Bldg. 4th FL, 492-16 Sinwol 2-dong, Yangcheon-gu,Seoul, 158-838, Korea

Corresponding Author: Sun-Jip Kim ,Tel: +82-2-2607-9244, Fax: +82-2-697-4177, Email: sunjipkim@yahoo.co.kr

Received: April 6, 2004; Accepted: July 5, 2004.

ABSTRACT

The respirometric mass estimation technique (RMET) classified as an internal standardization method with dominant nitrifier (Nitrosomonas and Nitrobacter) measuring nitrogenous oxygen uptake rate was evaluated. The coefficients of variation of initial respirometric nitrogenous oxygen uptake rates were 2.6 % and 1.5 % for nitrifier and Nitrobacter. Ammonium-nitrogen and nitrite-nitrogen removals equivalent to oxygen uptake were 0.21 mg/mg and 0.61 mg/mg, respectively. The initial substrate to biomass ratio affects the measuring of nitrogenous oxygen uptake rate and requires to be maintained above 11.3 g/g. It is necessary to eliminate the carbon dioxide uptake by nitrifier causing under estimation of nitrifier mass. Washing the sample before initiation of mass estimation is also necessary to minimize soluble organics which causes an interaction between heterotrophs and autotrophs. The RMET as a reliable, rapid and convenient tool can be replaced the conventional water quality analysis method. The severe fluctuations of Nitrosomonas and Nitrobacter concentrations were observed according to the oxidation and reduction states in the chambers of the Bardenpho 4 stage system fed with grain distillery wastewater having high concentrations of organics and nitrogen. The Nitrosomonas concentrations were in the range of 45-193 mg/L through all chambers of the system while the Nitrobacter concentrations were 8-129 mg/L.

Keywords: respirometric mass estimation technique | nitrogenous oxygen uptake rate | nitrifier | nitrification | respirometry