volume | PIER Journals

Abstract

The complex permittivity of thickened waste activated sludge (WAS) was measured from 3 MHz to 40 GHz. The solid content of the thickened WAS sample was varied from 4.5% to 18% by weight. The permittivity spectra exhibit features typical of biological tissues that have a high water content. At high frequencies, a Debye type dispersion is observed with a relaxation rate of 19 GHz characteristic of the bulk water in the sample (γ-dispersion). At lower frequencies, the solid content of the samples determines the properties of the permittivity. The onset of the so-called β-dispersion, attributed to the charging of cell membranes, occurs between 10-100 MHz. For samples with higher solid concentrations, a weak dispersion of the real part of the permittivity, characteristic of bound water, was observed at intermediate frequencies (δ-dispersion).

1. Li, , D. H. and J. J. Ganczarczyk, "Structure of activated sludge floes," Biotechnol. Bioeng., Vol. 35, No. 1, 57-65, 1990.
doi:10.1002/bit.260350109 Google Scholar

2. Appels, L., J. Baeyens, J. Degrµeve, and R. Dewil, "Principles and potential of the anaerobic digestion of waste-activated sludge," Prog. Energy Combust. Sci.,, Vol. 34, No. 6, 755-781, 2008.
doi:10.1016/j.pecs.2008.06.002 Google Scholar

3. Eskicioglu, C., K. J. Kennedy, and R. L. Droste, "Enhanced disinfection and methane production from sewage sludge by microwave irradiation," Desalination, Vol. 248, No. 1-3, 279-285, 2009.
doi:10.1016/j.desal.2008.05.066 Google Scholar

4. Saha, M., C. Eskicioglu, and J. Marin, "Microwave, ultrasonic and chemo-mechanical pretreatments for enhancing methane potential of pulp mill wastewater treatment sludge," Biores. Technol., Vol. 102, No. 17, 7815-7826, 2011.
doi:10.1016/j.biortech.2011.06.053 Google Scholar

5. Salerno, M. B., H.-S. Lee, P. Parameswaran, and B. E. Rittmann, "Using a pulsed electric field as a pretreatment for improved biosolids digestion and methanogenesis," Water Environ. Res. , Vol. 81, No. 8, 831-839, 2009.
doi:10.2175/106143009X407366 Google Scholar

6. Lee, I.-S., P. Parameswaran, J. N. Alder, and B. E. Rittmann, "Feasibility of focused-pulsed treated waste activated sludge as a supplemental electron donor for denitrification," Water Environ. Res., Vol. 82, No. 23, 2316-2324, 2010.
doi:10.2175/106143010X12609736967288 Google Scholar

7. Sheng, J., R. Vannela, and B. E. Rittmann, "Evaluation of cell-disruption effects of pulsed-electric-field treatment of synechocystis PCC 6803," Environ. Sci. Technol., Vol. 45, No. 8, 3795-3802, 2011.
doi:10.1021/es103339x Google Scholar

8. Park , B., J.-H. Ahn, J. Kim, and S. Hwang, "Use of microwave pretreatment for enhanced anaerobiosis of secondary sludge," Water Sci. Technol., Vol. 50, No. 9, 17-23, 2004. Google Scholar

9. Eskicioglu , C., K. J. Kennedy, and R. L. Droste, "Enhancement of batch waste activated sludge digestion by microwave pretreatment," Water Environ. Res., Vol. 79, No. 11, 2304-2317, 2007.
doi:10.2175/106143007X184069 Google Scholar

10. Hong, S. M., J. K. Park, N. Terradej, Y. O. Lee, Y. K. Cho, and C. H. Park, "Pretreatment of sludge with microwaves for pathogen destruction and improved anaerobic digestion performance," Water Environ. Res., Vol. 78, No. 1, 76-83, 2006.
doi:10.2175/106143005X84549 Google Scholar

11. Kaatze, U. and Y. Feldman, "Broadband dielectric spectrometry of liquids and biosystems," Meas. Sci. Technol., Vol. 17, No. 2, R17-R35, 2006.
doi:10.1088/0957-0233/17/2/R01 Google Scholar

12. Stuchly , M. A. and S. S. Stuchly, "Coaxial line reflection methods for measuring dielectric properties of biological substances at radio and microwave frequencies --- a review," IEEE Trans. Instrum. Meas., Vol. 29, No. 3, 176-183, 1980.
doi:10.1109/TIM.1980.4314902 Google Scholar

13. Kraszewski , A., M. A. Stuchly, and S. S. Stuchly, "ANA claibration method for measurements of dielectric properties," IEEE Trans. Instrum. Meas., Vol. 32, No. 2, 385-387, 1983.
doi:10.1109/TIM.1983.4315084 Google Scholar

14. Bao, J.-Z., M. L. Swicord, and C. C. Davis, "Microwave dielectric characterization of binary mixtures of water, methanol, and ethanol," J. Chem. Phys., Vol. 104, No. 12, 4441-4445, 1996.
doi:10.1063/1.471197 Google Scholar

15. Buchner , R., J. Barthel, and J. Stauber, "The dielectric relaxation of water between 0^。C and 35^。C," Chem. Phys. Lett.,, Vol. 306, No. 1-2, 57-63, 1999.
doi:10.1016/S0009-2614(99)00455-8 Google Scholar

16. Schwan , H. P., "Linear and nonlinear electrode polarization and biological materials," Ann. Biomed. Eng., Vol. 20, No. 3, 269-288, 1992.
doi:10.1007/BF02368531 Google Scholar

17. Raicu , V., T. Saibara, and A. Irimajiri, "Dielectric properties of rat liver in vivo: a noninvasive approach using an open-ended coaxial probe at audio/radio frequencies," Bioelectrochem. Bioenerg., Vol. 47, No. 2, 325-332, 1998.
doi:10.1016/S0302-4598(98)00171-8 Google Scholar

18. Pethig , R., "Dielectric properties of biological materials: biophysical and medical applications," IEEE Trans. Electr. Insul., Vol. 19, No. 5, 453-474, 1984.
doi:10.1109/TEI.1984.298769 Google Scholar

Professor Jake S. Bobowski

Dr. Thomas Johnson

Dr. Cigdem Eskicioglu