Effect of sludge age on simultaneous nitrification and denitrification in membrane bioreactor


Hocaoglu S. M. , INSEL G., Çokgör E. , ORHON D.

BIORESOURCE TECHNOLOGY, vol.102, no.12, pp.6665-6672, 2011 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 102 Issue: 12
  • Publication Date: 2011
  • Doi Number: 10.1016/j.biortech.2011.03.096
  • Title of Journal : BIORESOURCE TECHNOLOGY
  • Page Numbers: pp.6665-6672
  • Keywords: Membrane bioreactor, Simultaneous nitrification/denitrification (SNdN), Modelling, Sludge age, Black water, DOMESTIC WASTE-WATER, ACTIVATED-SLUDGE, NUTRIENT REMOVAL, NITROGEN REMOVAL, SYSTEMS, OXYGEN, REACTOR, MODEL, PERFORMANCE, DESIGN

Abstract

This study evaluated the effect of sludge age on simultaneous nitrification and denitrification in a membrane bioreactor treating black water. A membrane bioreactor with no separate anoxic volume was operated at a sludge age of 20 days under low dissolved oxygen concentration of 0.1-0.2 mg/l. Its performance was compared with the period when the sludge age was adjusted to 60 days. Floc size distribution, apparent viscosity, and nitrogen removal differed significantly, together with different biomass concentrations: nitrification was reduced to 40% while denitrification was almost complete. Modelling indicated that both nitrification and denitrification kinetics varied as a function of the sludge age. Calibrated values of half saturation coefficients were reduced when the sludge age was lowered to 20 days. Model simulation confirmed the validity of variable process kinetics for nitrogen removal, specifically set by the selected sludge age. (C) 2011 Elsevier Ltd. All rights reserved.