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The Scientific World Journal
Volume 2012, Article ID 751965, 6 pages
http://dx.doi.org/10.1100/2012/751965
Research Article

Effects of Experimental Conditions on Extraction Yield of Extracellular Polymeric Substances by Cation Exchange Resin

1Department of Environment & Energy, Sejong University, Seoul 143-747, Republic of Korea
2Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720, USA

Received 27 February 2012; Accepted 26 April 2012

Academic Editors: P. Fickers and W. Hunziker

Copyright © 2012 Jinwoo Cho et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Effects of experimental conditions on the yield of extracellular polymeric substances (EPSs) extraction by cation exchange resin (CER) were investigated using activated sludge flocs. The experimental variables included resin dose, extraction time, sample dilution, and storage time. An empirical model was proposed to describe the kinetics of extraction process. The extraction yield increases with the extraction time and CER dose until it reached the maximum amount of EPS extraction. The maximum yield of EPS was affected as well by the sample dilution, exhibiting a decreasing trend with increasing dilution factor. It was also found that the amount of EPS extracted from a raw sample depends on the storage time. Once EPS was extracted from the sample, however, the EPS keeps its original quantity under storage at 4°C. Based on the model, the maximum amount of EPS extraction and yield rate could be estimated for different conditions. Comparing the model parameters allows one to quantitatively compare the extraction efficiencies under various extracting conditions. Based on the results, we recommend the original sample should be diluted with the volume ratio of above 1 : 2 and a raw sample should be treated quickly to prevent the reduction of sample homogeneity and original integrity.