Extracellular Polymeric Substances Level Determines the Sludge Dewaterability in Bioleaching Process
Publication: Journal of Environmental Engineering
Volume 142, Issue 2
Abstract
Bioleaching treatments can significantly improve the dewaterability of sewage sludge. However, the exact mechanisms of the improvement of sludge dewaterability by bioleaching are as yet unclear. In this study, the variation of extracellular polymeric substances (EPS) content along with bound water content in sludge during bioleaching was investigated in detail. Results showed that sludge dewaterability was improved rapidly and then deteriorated slowly. The improvement of sludge dewaterability in the first 48 h of bioleaching was primarily attributable to the removal of sludge EPS, and the deterioration of sludge dewaterability in the following 144 h primarily resulted from the unexpected increase of sludge EPS amount in the latter stage of the bioleaching treatment. The Spearman correlation coefficients of EPS content and bound water content, EPS content and the specific resistance to filtration (SRF), and bound water content and SRF were 0.81, 0.83, and 0.94, respectively. Furthermore, the dewaterability of original sludge or the sludge being bioleached for eight days was improved by removing EPS through centrifugation, on the contrary, re-adding EPS especially from Acidithiobacillus ferrooxidans to bioleached sludge resulted in poor sludge dewaterability. Therefore, bioleaching is an innovative approach in enhancing sludge dewaterability, and an EPS level of bioleached sludge decides sludge dewaterability.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This work was supported by the National Natural Science Foundation of China (21277071 and 21307059) and the 863 High-tech Program of China (2012AA063501).
References
APHA (American Public Health Association). (2005). Standard methods for the examination of water and wastewater, 21st Ed., American Public Health Association, Washington, DC.
Bala Subramanian, S., Yan, S., Tyagi, R. D., and Surampalli, R. Y. (2010). “Extracellular polymeric substances (EPS) producing bacterial strains of municipal wastewater sludge: Isolation, molecular identification, EPS characterization and performance for sludge settling and dewatering.” Water Res., 44(7), 2253–2266.
Blais, J. F., Auclair, J. C., and Tyagi, R. D. (1992). “Cooperation between two Thiobacillus strains for heavy-metal removal from municipal sludge.” Can. J. Microbiol., 38(3), 181–187.
Brombacher, C., Bachofen, R., and Brandl, H. (1997). “Biohydrometallurgical processing of solids: A patent review.” Appl. Microbiol. Biot., 48(5), 577–587.
Carrere, H., et al. (2010). “Pretreatment methods to improve sludge anaerobic degradability: A review.” J. Hazard. Mater., 183(1), 1–15.
Cetin, S., and Erdincler, A. (2004). “The role of carbohydrate and protein parts of extracellular polymeric substances on the dewaterability of biological sludges.” Water Sci. Technol., 50(9), 49–56.
Chen, Y., Yang, H., and Gu, G. (2001). “Effect of acid and surfactant treatment on activated sludge dewatering and settling.” Water Res. 35(11), 2615–2620.
Fang, D., and Zhou, L. X. (2006). “Effect of sludge dissolved organic matter on oxidation of ferrous iron and sulfur by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans.” Water Air Soil Poll., 171(1–4), 81–94.
Fernandez-Polanco, F., et al. (2008). “Continuous thermal hydrolysis and energy integration in sludge anaerobic digestion plants.” Water Sci. Technol., 57(8), 1221–1226.
Gavala, H. N., Yenal, U., Skiadas, I. V., Westermann, P., and Ahring, B. K. (2003). “Mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. Effect of pre-treatment at elevated temperature.” Water Res., 37(19), 4561–4572.
Gu, X. Y., and Wong, J. W. C. (2007). “Degradation of inhibitory substances by heterotrophic microorganisms during bioleaching of heavy metals from anaerobically digested sewage sludge.” Chemosphere, 69(2), 311–318.
Guellil, A., Boualam, M., Quiquampoix, H., Ginestet, P., Audic, J., and Block, J. (2001). “Hydrolysis of wastewater colloidal organic matter by extracellularenzymes extracted from activated sludge flocs.” Water Sci. Technol., 43(6), 33–40.
Huo, M., Zheng, G., and Zhou, L. (2014). “Enhancement of the dewaterability of sludge during bioleaching primarily controlled by microbial quantity change and the decrease of slime extracellular polymeric substances content.” Bioresour. Technol., 168, 190–197.
Jin, B., Wilén, B. M., and Lant, P. (2004). “Impacts of morphological, physical and chemical properties of sludge flocs on dewaterability of activated sludge.” Chem. Eng. J., 98(1), 115–126.
Kim, J., et al. (2003). “Effects of various pretreatments for enhanced anaerobic digestion with waste activated sludge.” J. Biosci. Bioeng., 95(3), 271–275.
Lee, D. J., Lai, J. Y., and Mujumdar, A. S. (2006). “Moisture distribution and dewatering efficiency for wet materials.” Dry Technol., 24(10), 1201–1208.
Lehmann, E. L., and D’Abrera, H. J. M. (1998). Nonparametrics: Statistical methods based on ranks, Prentice-Hall, NJ.
Li, H., Wen, Y., Cao, A., Huang, J., Zhou, Q., and Somasundaran, P. (2012). “The influence of additives (, , and ) on the interaction energy and loosely bound extracellular polymeric substances (EPS) of activated sludge and their flocculation mechanisms.” Bioresource Technol., 114, 188–194.
Li, X. Y., and Yang, S. F. (2007). “Influence of loosely bound extracellular polymeric substances (EPS) on the flocculation, sedimentation and dewaterability of activated sludge.” Water Res., 41(5), 1022–1030.
Liu, F., Zhou, J., Wang, D., and Zhou, L. (2012a). “Enhancing sewage sludge dewaterability by bioleaching approach with comparison to other physical and chemical conditioning methods.” J. Environ. Sci., 24(8), 1403–1410.
Liu, F., Zhou, L., Zhou, J., Song, X., and Wang, D. (2012b). “Improvement of sludge dewaterability and removal of sludge-borne metals by bioleaching at optimum pH.” J. Hazard. Mater., 221(30), 170–177.
Liu, H., and Fang, H. H. P. (2002). “Extraction of extracellular polymeric substances (EPS) of sludges.” J. Biotechnol., 95(3), 249–256.
Liu, Y., and Fang, H. H. P. (2003). “Influences of extracellular polymeric substances (EPS) on flocculation, settling, and dewatering of activated sludge.” Environ. Sci. Technol., 33(3), 237–273.
Lu, M. C., Lin, C. J., Liao, C. H., Huang, R. Y., and Ting, W. P. (2003). “Dewatering of activated sludge by Fenton’s reagent.” Adv. Environ. Res., 7(3), 667–670.
Mercier, G., Drogui, P., Blais, J. F., and Chartier, M. (2006). “Pilot-plant study of wastewater sludge decontamination using a ferrous sulfate bioleaching process.” Water Environ. Res., 78(8), 872–879.
Neyens, E., and Baeyens, J. (2003). “A review of thermal sludge pre-treatment processes to improve dewaterability.” J. Hazard. Mater., 98(1), 51–67.
Neyens, E., Baeyens, J., Dewil, R., and De heyder, B. (2004). “Advanced sludge treatment affects extracellular polymeric substances to improve activated sludge dewatering.” J. Hazard. Mater., 106(2–3), 83–92.
Ni, B. J., et al. (2009). “Characterization of extracellular polymeric substances produced by mixed microorganisms in activated sludge with gel-permeating chromatography, excitation-emission matrix fluorescence spectroscopy measurement and kinetic modeling.” Water Res., 43(5), 1350–1358.
Park, C., Muller, C. D., Abu-Orf, M. M., and Novak, J. T. (2006). “The effect of wastewater cations on activated sludge characteristics: Effects of aluminum and iron in floc.” Water Environ. Res., 78(1), 31–40.
Park, C., Novak, J. T., Helm, R. F., Ahn, Y. O., and Esen, A. (2008). “Evaluation of the extracellular proteins in full-scale activated sludges.” Water Res., 42(14), 3879–3889.
Pathak, A., Dastidar, M. G., and Sreekrishnan, T. R. (2009). “Bioleaching of heavy metals from sewage sludge: A review.” J. Environ. Manage., 90(8), 2343–2353.
Ras, M., Girbal-Neuhauser, E., Paul, E., Spérandio, M., and Lefebvre, D. (2008). “Protein extraction from activated sludge: An analytical approach.” Water Res., 42(8), 1867–1878.
SAS 9.2 [Computer software]. Cary, NC, SAS Institute.
Sheng, G. P., Yu, H. Q., and Li, X. Y. (2010). “Extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment systems: A review.” Biotechnol. Adv., 28(6), 882–894.
Sheng, G. P., Zhang, M. L., and Yu, H. Q. (2008). “Characterization of adsorption properties of extracellular polymeric substances (EPS) extracted from sludge.” Colloid Surface B, 62(1), 83–90.
Smith, J. K., and Vesilind, P. A. (1995). “Dilatometric measurement of bound water in wastewater sludge.” Water Res., 29(12), 2621–2626.
Tichý, R., Janssen, A., Grotenhuis, J. T. C., Lettinga, G., and Rulkens, W. H. (1994). “Possibilities for using biologically-produced sulphur for cultivation of Thiobacilli with respect to bioleaching processes.” Bioresource Technol., 48(3), 221–227.
Tyagi, R. D., Couillard, D., and Tran, F. (1988). “Heavy metals removal from anaerobically digested sludge by chemical and microbiological methods.” Environ. Pollut., 50(4), 295–316.
Vaxelaire, J., and Cézac, P. (2004). “Moisture distribution in activated sludges: A review.” Water Res., 38(9), 2215–2230.
Wang, S., Zheng, G., and Zhou, L. (2010). “Heterotrophic microorganism Rhodotorula mucilaginosa R30 improves tannery sludge bioleaching through elevating dissolved CO2 and extracellular polymeric substances levels in bioleach solution as well as scavenging toxic DOM to Acidithiobacillus species.” Water Res., 44(18), 5423–5431.
Wilén, B. M., Jin, B., and Lant, P. (2003). “The influence of key chemical constituents in activated sludge on surface and flocculating properties.” Water Res., 37(9), 2127–2139.
Wong, J. W. C., Xiang, L., Gu, X. Y., and Zhou, L. X. (2004). “Bioleaching of heavy metals from anaerobically digested sewage sludge using FeS2 as an energy source.” Chemosphere, 55(1), 101–107.
Wotton, R. S. (2005). “The essential role of exopolymers (EPS) in aquatic systems.” Oceanogr. Mar. Biol., 42, 57–94.
Xiong, H., Song, L., Xu, Y., Tsoi, M. Y., Dobretsov, S., and Qian, P. Y. (2007). “Characterization of proteolytic bacteria from the Aleutian deep-sea and their proteases.” J. Ind. Microbiol. Biot., 34(1), 63–71.
Xu, H., Liu, Y., and Tay, J. H. (2006). “Effect of pH on nickel biosorption by aerobic granular sludge.” Bioresource Technol., 97(3), 359–363.
Yang, X., Wang, X., and Wang, L. (2010). “Transferring of components and energy output in industrial sewage sludge disposal by thermal pretreatment and two-phase anaerobic process.” Bioresource Technol., 101(8), 2580–2584.
Zheng, G., Zhou, L., and Wang, S. (2009). “An acid-tolerant heterotrophic microorganism role in improving tannery sludge bioleaching conducted in successive multibatch reaction systems.” Environ. Sci. Technol., 43(11), 4151–4156.
Zhou, L. (2012). “Bioleaching role in improving sludge in-deep dewatering and removal of sludge-borne metals and its engineering application.” J. Nanjing Agric. Univ., 35(5), 154–166 (in Chinese).
Zhou, L. X., Fang, D., Wang, S. M., Wong, J. W. C., and Wang, D. Z. (2005). “Bioleaching of Cr from tannery sludge: The effects of initial acid addition and recycling of acidified bioleached sludge.” Environ. Technol., 26(3), 277–284.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 142 • Issue 2 • February 2016
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Apr 13, 2014
Accepted: Jun 22, 2015
Published online: Sep 9, 2015
Published in print: Feb 1, 2016
Discussion open until: Feb 9, 2016
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.