Iranica Journal of Energy and Environment (Aug 2011)
Anaerobic Biodegradation of Phenol: Comparative Study of Free and Immobilized Growth
Abstract
Biodegradation of phenol using adapted free and immobilized mixed cultures were investigated. The culture was grown under anaerobic condition at room temperature of about 25°C and initial pH of 7.0.The initial concentration of phenol was in the range of 70 to 1000 mg/l. The culture was able to degrade phenol effectively up to 700 mg/l. The immobilized cells were able to remove phenol at concentration of 100 to700 mg/l in a slightly shorter time period. At phenol concentration of 1000 mg/l, the removal efficiency was enhancedfrom 10 to about 40% in the presence of immobilized cells. The biodegradation rate of phenol improved when immobilized cells were applied. Maximum biodegradation rate happened at phenol concentration of 700 mg/l which was 2.13 and 2.65 mg/l.h for free and immobilized cells, respectively. Monod and Haldane models were used to estimate the growth kinetics. Monod model was unable to predict efficiently the growth kinetics. However, Haldane model was correlated favorably with experimental data; with a correlation coefficient of R2 = 0.962. Haldane kinetic parameters, μ , K and K were 0.038 h- 1 , 18.87 and 339 mg/l, respectively.
