TY - JOUR
T1 - Determination of optimal phenanthrene, sulfate and biomass concentrations for anaerobic biodegradation of phenanthrene by sulfate-reducing bacteria and elucidation of metabolic pathway
AU - Tsai, Jen Chieh
AU - Kumar, Mathava
AU - Chang, Su-Min
AU - Lin, Jih-Gaw
PY - 2009/11/15
Y1 - 2009/11/15
N2 - Anaerobic biodegradation of phenanthrene (PHE) was investigated using an enrichment culture consists predominantly of sulfate-reducing bacteria (87 ± 6%). Aqueous biodegradation experiments were designed using the rotatable central composite design with five levels. The designed concentrations were 2-50 mg L-1 for PHE, 480-3360 mg L-1 for sulfate, and 5-50 mg L-1 for initial biomass. Experimental results indicated that the biomass concentration was the most significant variable, followed by the sulfate and PHE concentrations. The desirability functions methodology (DFM) was applied to find out the maximum specific PHE removal rate (Rs). The maximum Rs of 9.0 mg g-1 VSS d-1 within the designed ranges was obtained when the initial PHE, sulfate and biomass concentrations were 18.5, 841 and 50 mg L-1, respectively. The Rs observed in the present study was higher than the values reported in the previous studies. Subsequently, a confirmation study was performed under the optimal conditions, and the results matched well with the Rs estimated using DFM. Samples collected during PHE biodegradation experiments inferred the formation of two novel metabolic intermediates, 2-methyl-5-hydroxybenzaldehyde and 1-propenyl-benzene, and subsequently degraded to p-cresol, phenol and hydrocarbons.
AB - Anaerobic biodegradation of phenanthrene (PHE) was investigated using an enrichment culture consists predominantly of sulfate-reducing bacteria (87 ± 6%). Aqueous biodegradation experiments were designed using the rotatable central composite design with five levels. The designed concentrations were 2-50 mg L-1 for PHE, 480-3360 mg L-1 for sulfate, and 5-50 mg L-1 for initial biomass. Experimental results indicated that the biomass concentration was the most significant variable, followed by the sulfate and PHE concentrations. The desirability functions methodology (DFM) was applied to find out the maximum specific PHE removal rate (Rs). The maximum Rs of 9.0 mg g-1 VSS d-1 within the designed ranges was obtained when the initial PHE, sulfate and biomass concentrations were 18.5, 841 and 50 mg L-1, respectively. The Rs observed in the present study was higher than the values reported in the previous studies. Subsequently, a confirmation study was performed under the optimal conditions, and the results matched well with the Rs estimated using DFM. Samples collected during PHE biodegradation experiments inferred the formation of two novel metabolic intermediates, 2-methyl-5-hydroxybenzaldehyde and 1-propenyl-benzene, and subsequently degraded to p-cresol, phenol and hydrocarbons.
KW - Anaerobic biodegradation
KW - Phenanthrene
KW - Sulfate-reducing bacteria
UR - http://www.scopus.com/inward/record.url?scp=70349263309&partnerID=8YFLogxK
U2 - 10.1016/j.jhazmat.2009.06.130
DO - 10.1016/j.jhazmat.2009.06.130
M3 - Article
C2 - 19616375
AN - SCOPUS:70349263309
SN - 0304-3894
VL - 171
SP - 1112
EP - 1119
JO - Journal of Hazardous Materials
JF - Journal of Hazardous Materials
IS - 1-3
ER -