Biodegradation kinetics of 2,4-dichlorophenol by acclimated mixed cultures.
The biodegradation kinetics of 2,4-dichlorophenol (2,4-DCP) by culture (Culture M) acclimated to mixture of 4-chlorophenol (4-CP) and 2,4-DCP and the culture (Culture 4) acclimated to 4-CP only were investigated in aerobic batch reactors. Also, pure strains isolated from mixed cultures were searched for their ability towards the biodegradation of 2,4-DCP. Culture 4 was able to completely degrade 2,4-DCP up to 80 mg/L within 30 h and removal efficiency dropped to 21% upon increasing initial concentration to 108.8 mg/L. When the Culture M was used, complete degradation of 2,4-DCP in the range of 12.5-104.4 mg/L was attained. A linear relationship between time required for complete degradation and initial 2,4-DCP concentrations was observed for both mixed cultures. It was observed that the Haldane equation can be used to predict specific degradation rate (SDR) (R(2)>0.99) as a function of initial 2,4-DCP concentrations and it adequately describes 2,4-DCP concentration profiles. Both of the mixed cultures settled well, which is important to maintain good removal efficiency for longer periods of time for real full-scale applications. Although the pure strains isolated from mixed cultures were found to have higher SDR of 2,4-DCP compared to mixed cultures, they did not settle well under quiescent conditions.
Sahinkaya
Erkan
E
Middle East Technical University, Environmental Engineering Department, 06531 Ankara, Turkey. erkans@metu.edu.tr
Dilek
Filiz B
FB
D001419:Bacteria / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002478:Cells, Cultured; D002733:Chlorophenols / Q000737:chemistry* / Q000378:metabolism*; D003470:Culture Media; D007700:Kinetics; D013997:Time Factors
D002733:Chlorophenols; D003470:Culture Media; C029107:4-chlorophenol; C004762:2,4-dichlorophenol