Calculation of internal-mass-transfer coefficients in porous bodies on the basis of adsorption isotherms

1977 ◽  
Vol 32 (4) ◽  
pp. 408-411
Author(s):  
P. P. Zolotarev ◽  
Ya. I. Rabinovich ◽  
N. V. Churaev
Keyword(s):  
Mass Transfer ◽  
Adsorption Isotherms ◽  
Internal Mass ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Porous Bodies ◽  
Internal Mass Transfer

Kinetic Studies of Adsorption-Desorption of Cd and Zn Onto Al2O3/Solution Interfaces

1993 ◽  
Vol 28 (7) ◽  
pp. 39-45 ◽  
Author(s):  
K. S. L. Lo ◽  
J. O. Leckie
Keyword(s):  
Mass Transfer ◽  
Mass Transport ◽  
Metal Ion ◽  
Internal Diffusion ◽  
Internal Mass ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Near Surface ◽  
Film Diffusion ◽  
Slow Stage

The effects of external and internal mass transport limitations on zinc and cadmium adsorption onto the porous amorphous aluminium oxide/solution interfaces were studied. A modified two-stage rate model was used to interpret the experimental results. The rapid stage results from external surface film diffusion and internal diffusion into the near surface pores. The slow stage results from internal mass transport and extends over several days. The mass transfer-adsorption coefficients of the rapid stage are almost two orders of magnitude larger than those of the slow stage. The external mass transfer coefficients show an increasing trend with increasing pH, and appear to be affected by the charge/potential condition of the oxide/solution interface. The internal mass transfer coefficients indicate a uniform trend for both the zinc and cadmium results. The desorption rates and final metal ion solution concentrations are affected by the bulk solution pH. Film diffusion and internal diffusion are affected by the higher relative ratio of metal ion concentration to adsorbent concentration.

Henry's constants and mass transfer coefficients of halogenated organic pollutants in an air stripping packed column

1998 ◽  
Vol 38 (6) ◽  
pp. 287-294 ◽  
Author(s):  
Pen-C. Chiang ◽  
Chung-H. Hung ◽  
J. C. Mar ◽  
E. E. Chang
Keyword(s):  
Mass Transfer ◽  
Methylene Chloride ◽  
Packed Column ◽  
Transfer Coefficients ◽  
Chlorinated Organic Compounds ◽  
Air Stripping ◽  
Mass Transfer Coefficients ◽  
Equilibrium Partition ◽  
Henry's Constants ◽  
Chlorinated Organic

Both Henry's constants and volumetric mass transfer coefficients (KLa) of eight priority chlorinated organic compounds including 1,1-dichloroethene, methylene chloride, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethylene, and 1,4-dichlorobenzene in an air stripping packed column were investigated in this study. The liquid and gas phase EPICS (Equilibrium Partition in Closed System) and direct calculating methods were applied to determine the Henry's constants of VOCs. The interference of co-solute on Henry's constants was also investigated. Experimental results indicated that decrease in Henry's constants of VOCs was observed in the presence of humic acid but no apparent effect on Henry's constants was detected when there was NaCl and surfactant in solution. Four different configurations of packing media including Intalox Saddle, Super Intalox Saddle, Telleret, and Hedgehog made of polypropylene were respectively packed in the air stripping tower and investigated in the study. The dependence of hydraulic loading, air-water ratio, and configurations of packing media on mass transfer coefficients of VOCs was discussed.

Transport of chlorinated hydrocarbons between sewage and sewer atmosphere

1996 ◽  
Vol 34 (3-4) ◽  
pp. 557-564 ◽  
Author(s):  
Bettina S. Haas ◽  
Reimer Herrmann
Keyword(s):  
Mass Transfer ◽  
Aromatic Compounds ◽  
Chlorinated Hydrocarbons ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Sewerage System ◽  
Mass Fluxes ◽  
Single Compound

Sewage containing volatile contaminants is a potential VOC-source in cities. Thus we tried to evaluate volatilization out of the sewerage system by measurements of contaminants in sewer gas and sewage. Our results from a medium sized town with little industry showed that sewer gas is mainly contaminated with alkanes, small aromatic compounds and chlorinated hydrocarbons. For three chlorinated hydrocarbons (chloroform, trichloroethene, tetrachloroethene) we determined mass transfer coefficients out of sewage and used these data to estimate mass fluxes from sewage and emissions out of the sewerage system for two sewer stretches. Considerable emission of chlorinated hydrocarbons from sewage, i.e. fluxes of some 10 to 100 g per m2·d, occurred only when the contaminant input via sewage was between some g and mg per litre for a single compound. For concentrations that were about 3 orders of magnitude less, emissions were negligible.

Mass Transfer in Liquid in an Apparatus with Mobile Packing. Application of a Dispersion Model

1993 ◽  
Vol 58 (5) ◽  
pp. 1078-1086
Author(s):  
Zdeněk Palatý
Keyword(s):  
Experimental Data ◽  
Mass Transfer ◽  
Empirical Equation ◽  
Dispersion Model ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients

The paper deals with the mass transfer in a liquid on a plate with mobile packing. A procedure has been suggested which enables estimation of the mass transfer coefficients from experimental data considering the dispersion flow of the liquid. The results obtained from the desorption of CO2 from water are presented graphically and in the form of empirical equation.

On the convective diffusion under partial slip at wall

1989 ◽  
Vol 54 (4) ◽  
pp. 967-980 ◽  
Author(s):  
Ondřej Wein ◽  
Petr Kučera
Keyword(s):  
Mass Transfer ◽  
Numerical Solution ◽  
Analytic Solution ◽  
Convective Diffusion ◽  
Linear Velocity ◽  
Partial Slip ◽  
Accurate Calculation ◽  
Transfer Coefficients ◽  
Empirical Formulas ◽  
Mass Transfer Coefficients

Extended Leveque problem is studied for linear velocity profiles, vx(z) = u + qz. The existing analytic solution is reconsidered and shown to be inapplicable for the accurate calculation of mean mass-transfer coefficients. A numerical solution is reported and its accuracy is checked in detail. Simple but fairly accurate empirical formulas are suggested for the calculating of local and mean mass-transfer coefficients.

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