Cometabolic biodegradation of 4-chlorophenol by sequencing batch reactors at different temperatures.
The simultaneous removal of 4-chlorophenol (4-CP) and phenol in lab-scale sequencing batch reactors at different temperatures has been studied. Phenol feed concentration was fixed at 525 mg/L and 4-CP concentration was increased from 105 to 2100 mg/L at a constant hydraulic residence time (HRT) of 10.5 d. Complete phenol and 4-CP biodegradation was achieved during the aerobic stage working with 4-CP concentrations up to 1470 mg/L in the feed. Both 4-CP and phenol specific initial removal rates were strongly affected by 4-CP feed concentration and temperature. Only at the highest temperature tested (35 degrees C) it was possible to increase the maximum assimilative 4-CP concentration by the biological sludge up to 2100 mg/L, and a significant reduction of the ecotoxicity of the effluents was observed. 4-chlorocatechol (4-CC) was identified as the major intermediate in the aerobic cometabolic 4-CP degradation, being the ecotoxicity of that species substantially lower than that of 4-CP.
Monsalvo
V M
VM
Sección de Ingeniería Química, Facultad de Ciencias, Universidad Autónoma de Madrid., Campus de Cantoblanco, Crta. Colmenar km 15, Madrid, Spain. victor.monsalvo@uam.es
Mohedano
A F
AF
Casas
J A
JA
Rodríguez
J J
JJ
D000064:Acclimatization; D000693:Anaerobiosis; D001673:Biodegradation, Environmental; D018533:Biomass; D019149:Bioreactors; D002733:Chlorophenols / Q000378:metabolism*; D054750:Ecotoxicology; D007700:Kinetics; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption; D010636:Phenols / Q000302:isolation & purification; D013696:Temperature; D013997:Time Factors
D002733:Chlorophenols; D010636:Phenols; C029107:4-chlorophenol; D010100:Oxygen