Mass transport and thermodynamic analysis of PAHs in partitioning systems in the presence and absence of ultrasonication

Abstract

in Wiley Online Library (wileyonlinelibrary.com).Transport of PAHs from Desmopan polymers to methanol under various mixing conditions and in the presence of ultrasound was analyzed. PAH transport was influenced by external transport resistances; however, agitation greater than 800 rpm yielded PAH transport completely limited by internal resistances. Delivery rates of phenanthrene, fluoranthene, and pyrene with ultrasonication were faster than that under any mixing condition, suggesting enhanced internal transport properties. Ultrasound also induced increased concentrations of PAHs in solution at equilibrium. The model developed described PAH delivery under sonicated/non-sonicated conditions, while quantifying diffusive and thermodynamic properties. Diffusivities with and without ultrasound decreased with permeant molecular size agreeing with coefficients determined for similar aromatic compounds in polymers. Partitioning coefficients under sonicated and non-sonicated conditions conclusively differed from each other and decreased as a function of PAH molecular size. Quantitative structure-property relationship data of PAHs yielded factors predicting thermodynamic and transport behaviors, with polarizability being the best descriptor. V V C 2010 American Institute of Chemical Engineers AIChE J,

Modeling of crude oil biodegradation using two phase partitioning bioreactor

“…In poor mixing conditions mass transfer between phases will become limited by the combination effects of internal and external resistance. This hypothesis is supported by the findings of the studies that have been carried out to determine mass transfer from polymer to the surrounding liquid phase . Moreover, interfacial area can act as a support for biological growth, which can directly utilize the released compounds from solid polymers, and mineral salts from the aqueous phase …”

“…This hypothesis is supported by the findings of the studies that have been carried out to determine mass transfer from polymer to the surrounding liquid phase. 48 Moreover, interfacial area can act as a support for biological growth, 49 which can directly utilize the released compounds from solid polymers, and mineral salts from the aqueous phase. 24 In poor mixing condition, suspended cells may overcome the shear stress at the liquid-solid interface.…”

Separation of ultrasonic contributions and energy utilization characteristics of ultrasonic regeneration

“…The absorption coefficient of ultrasound for the silica gel can be calculated by Eq. 8, and the experimental results are listed in Table 1 m s c p;s dt s ds 5a u dP ult (8) The determination of other parameters has been illustrated in our previous papers 17 and they are shown in appendix.…”

“…5,6 Power ultrasound (between about 20 and 100 kHz, a few tens of Watts), for the induced effects of heating, acoustic cavitation, and acoustic streaming, has been generally used for heat-and mass-transfer processes intensification. 7,8 Gogate et al [9][10][11][12] have made a deep study on different design of large scale sonochemical reactors and a model has been given to help to choose desired equipment.…”