Assessment of the limiting step of mass transfer in n-hexadecane biodegradation in a bubble column reactor

作者：Quijano Guillermo^*; Huerta Ochoa Sergio; Gutierrez Rojas Mariano

来源：Water Science and Technology, 2010, 62(4): 906-914.

DOI：10.2166/wst.2010.343

• biosurfactants
• limiting step
• mass transfer
• mathematical model
• n-hexadecane

A mathematical model was developed to assess limiting step of mass transfer in the n-hexadecane (HXD) biodegradation by a microbial consortium A double Monod kinetic (oxygen and HXD) for biomass production was successfully used to describe the experimental data Good fitting (r(2) = 0 92) between the model solution and experimental data was obtained The overall mass transfer coefficients for HXD, k(L)a(HXD), and oxygen, k(L)a(O2), were experimentally determined and biosurfactant production was indirectly determined through surface tension measurements in the aqueous phase It was observed that a surface tension reduction from 65 (Oh of culture) to 47 mN m (1) (240h of culture) was related to a decrease of 52% in the HXD droplet diameter and to an increase of 63% in k(L)a(HXD), respect the initial values Conversely, k(L)a(O2), was repressed up to 37% compared to the initial value The maximum rate analysis based on the mathematical model showed that HXD transfer was up to 5-fold lower than its consumption On the contrary, oxygen transfer was always higher than its consumption Thus, the limiting step under the working conditions was the HXD transfer to the aqueous phase However, slight reductions in k(L)a(O2) could result in oxygen transfer limitations during the last 60 h of the cultures

• 出版日期2010