Full Length Research Paper

Kinetic models of cell growth, substrate utilization and bio-decolorization of distillery wastewater by Aspergillus fumigatus U_B260

Mohammad Pazouki^1*, Ghasem Najafpour² and Mohammad Raouf Hosseini³

¹Department of Energy, Materials and Energy Research Center, Karaj, Iran.

²Faculty of Chemical Engineering, Noshirvani University of Technology, Babol, Iran.

³Department of Mining Engineering, Shahid Bahonar University, Kerman, Iran.

*Corresponding author. E-mail: mpazouki@merc.ac.ir. Tel: +98-261-6208943. Fax: +98-261-6201888.

Abbreviations: m_s, Maintenance coefficient (g substrate/g cells); P, biodecolorization responsible enzyme (metabolite) (g/l); S, substrate concentration (g/l); S₀,           initial substrate concentra-tion (g/l); T, biodecolorization time (h); X, cell concentration (g/l); X_m, maximum cell concentration (g/l); , yield factor for cells on carbon substrate (g cells/ g substrate); , growth-associated product formation coefficient (g/g); ,       non-growth-associated product formation coefficient (g/g.h); and , maximum specific growth rate (h^-1).

Accepted 14 March, 2008

Bio-decolorization kinetic studies of distillery effluent in a batch culture were conducted using Aspergillus fumigatus. A simple model was proposed using the Logistic Equation for the growth, Leudeking-Piret kinetics for bio-decolorization, and also for substrate utilization. The proposed models appeared to provide a suitable description for each parameter devoted to the growth phase. The biomass yield for 14 g/l substrate was 70.7%. The maximum specific growth rate (µ_m) of the obtained and fitted data is close to the calculated µ_m of the present research work ( ). It was found that the kinetic model for the bio-decolorization of distillery effluent was growth associated.

Key words: Bio-decolorization, kinetic models, distillery effluent, Logistic Equation, leudeking-Piret kinetics.