Effect of chromium(VI) on the biomass yield of activated sludge

Yetis U., Demirer G., Gokcay C.

ENZYME AND MICROBIAL TECHNOLOGY, vol.25, pp.48-54, 1999 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 25
  • Publication Date: 1999
  • Doi Number: 10.1016/s0141-0229(99)00013-7
  • Journal Name: ENZYME AND MICROBIAL TECHNOLOGY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.48-54
  • Keywords: activated sludge, biomass yield, Cr(VI), maintenance, stimulation
  • Middle East Technical University Affiliated: Yes

Abstract

Effect of 1-25 mg/l of influent Cr(VI) concentrations on true biomass yield (Y-t) and decay coefficient (k(d)) of activated sludge units was investigated in this study. To this purpose, completely mixed, once-through laboratory scale activated sludge units with acclimated cultures were operated. After obtaining dilute-out curves for each Cr(VI) concentration, the values of Y-t and k(d) were determined. The results revealed that presence of Cr(VI) caused stimulatory effects on biomass yield and maintenance up to the Cr(VI) concentration of 25 mg/l. Lower Cr(VI) concentrations exerted higher stimulation of the system. Extended oxidation due to the presence of Cr(VI) and/or increased synthesis of cellular material due to the stimulatory effects of Cr(VI) were thought to be the mechanisms of the observed stimulation. (C) 1999 Elsevier Science Inc. All rights reserved.