PMID- 12449314
OWN - NLM
STAT- MEDLINE
DCOM- 20030605
LR  - 20191106
IS  - 0923-9820 (Print)
IS  - 0923-9820 (Linking)
VI  - 13
IP  - 2
DP  - 2002
TI  - A detailed analysis of the mechanisms controlling the acceleration of 2,4-DCP 
      monooxygenation in the two-tank suspended growth process.
PG  - 117-30
AB  - The mechanisms underlying the observed acceleration of monooxygenation reactions 
      in two-tank accelerator/aerator suspended growth system are evaluated in detail. 
      The accelerator tank is characterized by a very high electron flow through 
      reduced nicotinamide adenine dinucleotide (NADH + H+), particularly when the 
      retention-time ratio is small. Only a small fraction of the electron flow was 
      diverted to oxygenation reactions, and the major sinks of NADH + H+ were 
      respiration and biomass synthesis. The main producer of NADH + H+ is oxidation of 
      acetate, a rapidly degraded electron-donor substrate. The half-maximum-rate 
      concentration for oxygen used in respiration was 0.03 mg/L, while the 
      half-maximum-rate concentration for oxygen used as a cosubstrate in 
      monooxygenation was 0.18 mg/L. Thus, monooxygenations were more sensitive to 
      oxygen limitation than was respiration. The NADH + H+ concentration had a direct 
      effect on the monooxygenation kinetics. The rate coefficients for both 
      monooxygenation reactions were directly proportional to the specific growth rate 
      in the accelerator, which supports that the accelerator tank caused an 
      up-regulation of the monooxygenase content. Because the rate coefficients in the 
      aerator tank were much larger than in the one-tank system, even though the 
      specific growth rates were nearly the same, monooxygenases may have carried over 
      from the accelerator tank to the aerator tank. Its higher concentration of 
      2,4-dichlorophenol (2,4-DCP) and the higher specific growth rate were the main 
      reasons why the accelerator had faster kinetics for 2,4-DCP utilization than did 
      the aerator tank. The apparently higher levels of monooxygenase in both tanks of 
      the two-tank system also appears be a primary reason why its performance was 
      substantially superior to that of the one-tank system in terms of 2,4-DCP 
      removal.
FAU - Dahlen, Elizabeth P
AU  - Dahlen EP
AD  - Exponent Failure Analysis Associates, Menlo Park, CA 94025, USA. 
      edahlen@exponent.com
FAU - Rittmann, Bruce E
AU  - Rittmann BE
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - Netherlands
TA  - Biodegradation
JT  - Biodegradation
JID - 9100834
SB  - IM
MH  - *Biodegradation, Environmental
EDAT- 2002/11/27 04:00
MHDA- 2003/06/06 05:00
CRDT- 2002/11/27 04:00
PHST- 2002/11/27 04:00 [pubmed]
PHST- 2003/06/06 05:00 [medline]
PHST- 2002/11/27 04:00 [entrez]
AID - 10.1023/a:1020498305731 [doi]
PST - ppublish
SO  - Biodegradation. 2002;13(2):117-30. doi: 10.1023/a:1020498305731.