| Title: | Modeling nonsteady-state conditions and kinetics of mass transport for hydrophobic compounds in activated-sludge treatment |
| Author(s): | Rittmann BE; Lee KC; Shi J; McAvoy DC; |
| Address: | "Department of Civil and Environmental Engineering, Northwestern University, Evanston, Illinois 60208-3109, USA. b-rittmann@northwestern.edu" |
| ISSN/ISBN: | 1061-4303 (Print) 1061-4303 (Linking) |
| Abstract: | "A new model that describes the fate of hydrophobic and volatile organic compounds in activated-sludge treatment includes two novel features. First, all of the mass balances are nonsteady state, which allows the model to describe the effects of transients in loading, temperature, or operation. Second, the model describes the mass transfer of hydrophobic compounds with kinetics, not equilibrium. A series of examples demonstrate the new features of the model and how they can be important. When the kinetics of mass transfer are not fast, hydrophobic compounds remain significantly out of equilibrium, even when the system is operating at steady state. When the loading of a hydrophobic compound increases, its aqueous-phase concentration approaches (but does not quite reach) its steady-state concentration much more rapidly than does the density of the adsorbed hydrophobic compound. Finally, the importance of mass-transport kinetics between the aqueous and sorbed phases suggests that research should be focused on this poorly understood mechanism in activated sludge" |
| Keywords: | "Adsorption Kinetics *Models, Theoretical Organic Chemicals/analysis Sewage/*chemistry Solubility Volatilization Water Movements Water Pollutants/*analysis;" |
| Notes: | "MedlineRittmann, Bruce E Lee, Kuan-Chun Shi, Jay McAvoy, Drew C eng 2003/07/03 Water Environ Res. 2003 May-Jun; 75(3):273-80. doi: 10.2175/106143003x141060" |
