TY - JOUR
T1 - Phenol and 4-chlorophenol biodegradation by yeast Candida tropicalis in a fluidized bed reactor
AU - Galíndez-Mayer, J.
AU - Ramón-Gallegos, J.
AU - Ruiz-Ordaz, N.
AU - Juárez-Ramírez, C.
AU - Salmerón-Alcocer, A.
AU - Poggi-Varaldo, H. M.
PY - 2008/2/15
Y1 - 2008/2/15
N2 - The objective of this work was to evaluate (i) the hydrodynamics and oxygen transfer characteristics of a fluidized bed reactor (FBR) and (ii) their performance in the continuous biodegradation of a phenol (Phe) and 4-chlorophenol (4-CP)-containing influent when the FBR was loaded with Candida tropicalis yeast immobilized onto granular activated carbon (GAC) particles. The first part was carried out in terms of the behavior of mixing time (tm95), bubble diameter (dB), gas hold-up (εG), gas-liquid interfacial area (a′) and oxygen transfer coefficient (kLa) in biphasic (gas-liquid) and triphasic (gas-liquid-carbon) systems, both batch-wise operated in pseudohomogeneous regime at superficial gas flow rates UG below 1.72 cm s-1. Mixing time was determined using a tracer technique, εG was measured by the volume expansion method; (dB) was determined by the procedure reported by Poulsen and Iversen and kLa was determined by a transient gassing-in technique. It was found that hydrodynamic variables were severely influenced by GAC particles. The dB values were smaller in triphasic than in biphasic system, with the consequent increase in the εG, a′ and kLa values. The removal efficiencies of both Phe and 4-CP in the bioreactor challenged at increasing volumetric loading rate of pollutants were determined in the second part of the study. Phe and 4-CP was determined by HPLC. Immobilized biomass on GAC was estimated from their total nitrogen content. Regarding continuous biodegradation experiments, the FBR was capable of efficiently removing Phe at volumetric loading rates as high as 60 mg Phe L-1 h-1 when it was fed as the sole carbon source. Beyond this point, removal efficiencies drastically decreased. When operated with a feed consisting of a mixture of Phe and 4-CP, the FBR was able to remove more than 98% of 4-CP in the range of volumetric loading rates of 4.1 mg 4-CP L-1 h-1 and 55 mg Phe L-1 h-1 with no apparent deterioration of bioreactor performance.
AB - The objective of this work was to evaluate (i) the hydrodynamics and oxygen transfer characteristics of a fluidized bed reactor (FBR) and (ii) their performance in the continuous biodegradation of a phenol (Phe) and 4-chlorophenol (4-CP)-containing influent when the FBR was loaded with Candida tropicalis yeast immobilized onto granular activated carbon (GAC) particles. The first part was carried out in terms of the behavior of mixing time (tm95), bubble diameter (dB), gas hold-up (εG), gas-liquid interfacial area (a′) and oxygen transfer coefficient (kLa) in biphasic (gas-liquid) and triphasic (gas-liquid-carbon) systems, both batch-wise operated in pseudohomogeneous regime at superficial gas flow rates UG below 1.72 cm s-1. Mixing time was determined using a tracer technique, εG was measured by the volume expansion method; (dB) was determined by the procedure reported by Poulsen and Iversen and kLa was determined by a transient gassing-in technique. It was found that hydrodynamic variables were severely influenced by GAC particles. The dB values were smaller in triphasic than in biphasic system, with the consequent increase in the εG, a′ and kLa values. The removal efficiencies of both Phe and 4-CP in the bioreactor challenged at increasing volumetric loading rate of pollutants were determined in the second part of the study. Phe and 4-CP was determined by HPLC. Immobilized biomass on GAC was estimated from their total nitrogen content. Regarding continuous biodegradation experiments, the FBR was capable of efficiently removing Phe at volumetric loading rates as high as 60 mg Phe L-1 h-1 when it was fed as the sole carbon source. Beyond this point, removal efficiencies drastically decreased. When operated with a feed consisting of a mixture of Phe and 4-CP, the FBR was able to remove more than 98% of 4-CP in the range of volumetric loading rates of 4.1 mg 4-CP L-1 h-1 and 55 mg Phe L-1 h-1 with no apparent deterioration of bioreactor performance.
KW - Bubble column
KW - Candida tropicalis
KW - Chlorophenol biodegradation
KW - Fluidized bed reactor
KW - Immobilized yeast
KW - Phenol biodegradation
UR - http://www.scopus.com/inward/record.url?scp=37349126662&partnerID=8YFLogxK
U2 - 10.1016/j.bej.2007.06.011
DO - 10.1016/j.bej.2007.06.011
M3 - Artículo
SN - 1369-703X
VL - 38
SP - 147
EP - 157
JO - Biochemical Engineering Journal
JF - Biochemical Engineering Journal
IS - 2
ER -