Respirometric evaluation of a mixture of organic chemicals with different biodegradation kinetics


Cokgor E. , INSEL G., AYDIN E., ORHON D.

JOURNAL OF HAZARDOUS MATERIALS, vol.161, no.1, pp.35-41, 2009 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 161 Issue: 1
  • Publication Date: 2009
  • Doi Number: 10.1016/j.jhazmat.2008.03.051
  • Title of Journal : JOURNAL OF HAZARDOUS MATERIALS
  • Page Numbers: pp.35-41
  • Keywords: Biodegradation, Chemical industry, Modeling, Process kinetics, Substrate inhibition, ACTIVATED-SLUDGE BEHAVIOR, ANOXIC CONDITIONS, WASTE-WATER, WASTEWATERS, SUBSTRATE, GROWTH, COD, IDENTIFICATION, RESPIRATION, HYDROLYSIS

Abstract

The study evaluated the biodegradation characteristics of a mixture of organics with different biodegradation characteristics in an integrated chemical plant effluent. The wastewater had a total chemical oxygen demand (COD) content of 12,800 mg/L, mostly Soluble and 93% biodegradable. The evaluation was based oil respirometry, and mainly consisted on model calibration and interpretation of the oxygen uptake rate data, which exhibited an original and specific profile with a sequence of two peaks and three plateaus. A specific model was defined for this purpose, which identified four different biodegradable COD components with significantly different process kinetics. The major fraction accounting for 57% of the total biodegradable COD in the wastewater had to be hydrolyzed before biodegradation with a low hydrolysis rate of 1.3 day(-1). The analysis of the experimental data showed that the oxygen utilization started with a delayed response after substrate addition. The delayed logarithmic phase could be characterized by a Haldane type of inhibition kinetics. (C) 2008 Elsevier B.V. All rights reserved.