Biodegradability assessment of ozonated raw and biotreated pharmaceutical wastewater

Arslan-Alaton I. , BALCIOGLU I.

ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, vol.43, no.4, pp.425-431, 2002 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 43 Issue: 4
  • Publication Date: 2002
  • Doi Number: 10.1007/s00244-002-1235-y
  • Page Numbers: pp.425-431


The activated sludge specific oxygen uptake rate (SOUR) and BOD5/COD ratios of biologically pretreated pharmaceutical wastewater were analyzed and compared to assess relative changes in biotreatability during ozonation at a rate of 7.4 g/(L x h) for 4 h. An appreciable COD removal (41%) was achieved by the initial biological treatment process, whereas ozonation was more effective in reducing the UV-sensitive aromatic compounds present in the pretreated effluent. Sequential treatment using activated sludge + ozonation processes resulted in an average COD removal efficiency of 48%, and a proceeding biotreatment stage increased the overall COD removal to 53%. An optimum ozone dose in the range of 1,8543,708 mg/L corresponding to a specific ozone input rate of 0.23-0.46 mg O-3/mg CODo existed where SOUR (3.7 x 10(-3) mg O-2/[mg MLSS x min] for ozonation at pH 8) and BOD5/COD (0.57) as well as the proceeding biological COD removal yield Y-COD (average 8 mg COD/mg MLSS) exerted maximum values.