Mathematical modeling of copper(II) ion inhibition on COD removal in an activated sludge unit

J Hazard Mater. 2007 Jul 19;146(1-2):372-7. doi: 10.1016/j.jhazmat.2006.12.033. Epub 2006 Dec 17.

Abstract

A mathematical model was developed to describe the Cu(II) ion inhibition on chemical oxygen demand (COD) removal from synthetic wastewater containing 15 mg l(-1) Cu(II) in an activated sludge unit. Experimental data obtained at different sludge ages (5-30 days) and hydraulic residence times (HRT) (5-25 h) were used to determine the kinetic, stoichiometric and inhibition constants for the COD removal rate in the presence and absence of Cu(II) ions. The inhibition pattern was identified as non-competitive, since Cu(II) ion inhibitions were observed both on maximum specific substrate removal rate (k) and on the saturation constant (Ks) with the inhibition constants of 97 and 18 mg l(-1), respectively, indicating more pronounced inhibition on Ks. The growth yield coefficient (Y) decreased and the death rate constant (b) increased in the presence of Cu(II) ions due to copper ion toxicity on microbial growth with inhibition constants of 29 and 200 mg l(-1), respectively indicating more effective inhibition on the growth yield coefficient or higher maintenance requirements. The mathematical model with the predetermined kinetic constants was able to predict the system performance reasonably well especially at high HRT operations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Copper* / chemistry
  • Models, Theoretical*
  • Sewage / microbiology*
  • Waste Disposal, Fluid
  • Water Pollutants, Chemical* / chemistry

Substances

  • Sewage
  • Water Pollutants, Chemical
  • Copper