Properties of Four Biological Flocs as Related to Settling
Publication: Journal of Environmental Engineering
Volume 130, Issue 11
Abstract
The influence of four industrial wastewater types (organic chemical, dye, leather, and winery industries) on the exopolymeric substances (EPSs) constituents [protein, polysaccharide, and deoxyribonucleic acid (DNA)] and physicochemical properties of flocs (contact angle, surface charge, and bound water) was determined. Four laboratory scale activated sludge systems were used; they were fed with real wastewaters and were operated continuously under steady-state conditions. The EPS analysis showed that between 70 and 80% of the extracellular organic material could be attributed to protein. The proteins in the bound form were quantitatively greater than the soluble protein form in winery industry floc EPSs. The soluble protein ratios were higher than bound protein ratios in organic chemical, dye, and leather industries flocs. Lower amounts of protein and high DNA content were found in the EPS flocs grown on wastewaters containing more complex substrates (organic chemical, leather, and dye). Changing the wastewater from chemical, leather, and dye to that of winery industry resulted in an increase in protein and a decrease in DNA level of floc EPSs. The sludge surface of winery industry flocs were less hydrophobic (small contact angle) and more highly negatively charged compared to chemical, dye, and leather industry flocs. A higher sludge volume index (SVI), an indication of poorer settleability, was associated with both small amounts of EPS and protein and a high amount of DNA. Both high hydrophilic and negatively charged surfaces corresponded to lower levels of SVI and good settling properties. The results of this study demonstrated that wastewater type influenced the EPS composition and physicochemical properties of sludge. The surface properties (surface charge, contact angle, and bound water) and composition of EPS, apart from the carbohydrate content, governed the settleability of sludge and were important in controlling the SVI.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
American Public Health Association, American Water Works Association, Water Pollution Control Federation (APHA-AWWA-WPCF). ( 1992). Standard methods for the examination of water and wastewater, 18th Ed., Washington, D.C.
2.
Arda, M. ( 1978). General bacteriology, Ankara University Press, Ankara, Turkey.
3.
Atlas, R.M., and Parks, L.C. ( 1993). Handbook of microbiological media, CRC, Boca Raton, Fla.
4.
Azeredo, J., Oliveira, R., and Lazarova, V. (1998). “A new method for extraction of exopolymers from activated sludges.” Water Sci. Technol., 37(4–5), 367–370.
5.
Boyette, S. M., Lowette, J. M., Gadoba, W. G., and Soares, J. A. (2001). “Cell surface and exopolymer characterization of laboratory stabilized activated sludge from a beverage bottling plant.” Water Res., 21(4), 236–259.
6.
Brown, M. J., and Lester, J. N. (1979). “Metal removal in activated sludge: the role of bacterial extracellular polymers.” Water Res., 13(5), 817–837.
7.
Brown, M. J., and Lester, J. N. (1980). “Comparison of bacterial extracellular polymer extraction methods.” Appl. Environ. Microbiol., 40(6), 179–185.
8.
Brunk, C. F., Jones, K. C., and James, J. W. (1979). “Assay for monogram quantities of DNA in cellular homogenates.” Anal. Biochem., 92(8), 179–185.
9.
Bura, R., Cheung, M., Liao, B., Finlayson, C., and Lee, B. C. (1998). “Composition of extracellular polymeric substances in the activated sludge floc matrix.” Water Sci. Technol., 37(4–5), 325–333.
10.
Chao, A. C., and Keinath, T. M. (1979). “Influence of process loading intensity on sludge clarification and thickening characteristics.” Water Res., 35(6), 1029–1037.
11.
Dignac, M. F., Urbain, V., Rybacki, D., Bruchet, A., Snidaro, D., and Scribe, P. (1998). “Chemical description of extracellular polymers: Implications on activated sludge floc structure.” Water Sci. Technol., 38(8), 45–53.
12.
Dobbs, R. A., Wang, L., and Godwin, R. (1989). “Sorption of toxic organic compounds on wastewater solids: correlation with fundamental properties.” Environ. Sci. Technol., 23, 1092–1097.
13.
Dondero, N. C., Phillips, R. A., and Heukelekian, H. (1961). “General identification of filamentous bacteria.” Appl. Microbiol., 9, 219–227.
14.
Dubois, M., Gilles, K. A., Hamilton, J. K., Rebers, P. A., and Smith, F. (1956). “Colorimetric method for determination of sugars and related substances.” Anal. Chem., 28(3), 350–356.
15.
Dugan, P. R., and Lundgren, D. C. (1968). “Isolation of activated sludge micro-organisms.” Appl. Microbiol., 8, 357–361.
16.
Duncan-Hewitt, W. C., Policova, Z., Cheng, P., Vargha-Butler, E. I., and Neumann, A. W. (1989). “Semi-automatic measurement of contact angles on cell layers by a modified axis symmetric drop shape analysis.” Colloids Surf., 42, 391–402.
17.
Eikelbooom, D.H., and van Buisen, H.J. J. ( 1983). “Microscopic sludge investigation manual.” IMG TNO Rep. No. A 94a, Delft, Holland.
18.
Ekama, G. A., Dold, P. L., and Marais, G. R. (1986). “Procedures for determining influent COD fractions and the maximum specific growth rate of heterothrophs in activated sludge systems.” Water Sci. Technol., 18(8), 91–114.
19.
Eriksson, L., and Alm, B. (1991). “Study of flocculation mechanisms by observing effects of a complexing agent on activated sludge properties.” Water Sci. Technol., 24(7), 21–28.
20.
Finlayson, J. E., Liao, B., Droppo, I. G., and Leppard, G. G. (1998). “The relationship between the structure of activated sludge flocs and the sorption of hydrophobic pollutants.” Water Sci. Technol., 37(4–5), 353–357.
21.
Forster, C. F. (1985). “Factors involved in the settlement of activated sludge 1. Nutrients and surface polymers.” Water Res., 19(10), 1259–1264.
22.
Frolund, B., Griebe, T., and Nielsen, P. H. (1995). “Enzymatic activity in the activated sludge floc matrix.” Appl. Microbiol. Biotechnol., 43, 755–761.
23.
Frolund, B., Keiding, K., and Nielsen, P. H. (1994). “A comparative study of biopolymers from a conventional and an advanced activated sludge treatment plant.” Water Sci. Technol., 29(7), 137–141.
24.
Frolund, B., Palmigren, R., Keidin, G. K., and Nielsen, P. H. (1996). “Extraction of extracellular polymer from activated sludge using a cation exchange resin.” Water Res., 30(2), 1749–1758.
25.
Germirli, F., Orhon, D., and Artan, N. (1991). “Assessment of the initial inert soluble COD in industrial wastewaters.” Water Sci. Technol., 23(6), 1077–1086.
26.
Goel, M., Satoh, H., and Matsuo, T. (1997). “Effect of electron acceptor conditions on hydralitic enzyme synthesis in bacterial cultures.” Water Res., 31(6), 2597–2603.
27.
Goodwin, J. A. S., and Forster, C. F. (1985). “A further examination into the composition of activated sludge surfaces in relation to their settlement characteristics.” Water Res., 19(8), 527–533.
28.
Harris, R.H., and Mitchell, R. ( 1973). “The role of polymers in microbial aggregation.” Review of Microbiology, Marcel Dekker, New York.
29.
Harris, V., and Mitchell, R. (1975). “Inhibition of the flocculation of bacteria by biopolymers.” Water Res., 9, 993–999.
30.
Higgins, M. J., and Novak, J. J. (1997a). “Characterization of exocellular protein and its role in bioflocculation.” J. Environ. Eng., 123(5), 479–485.
31.
Higgins, M. J., Novak, J. J., (1997b). “The effect of cations on settling and dewatering of activated sludge.” Water Environ. Res., 69, 215–223.
32.
Jenkins, D., Richard, M.G., and Daigger, G.T. ( 1993). Manual on the causes and control of activated sludge bulking and foaming, 2nd Ed., Lewis, Boca Raton, Fla.
33.
Jia, X. S., Fang, H. H. P., and Furumai, H. (1996). “Surface charge and extracellular polymer of sludge in anaerobic degradation.” Water Sci. Technol., 34(5–6), 309–316.
34.
Jorand, F., Boue-Bigne, F., Black, J.-C., and Urbain, V. (1998). “Hydrophobicity/hydrophilic properties of activated sludge exopolymeric substances.” Water Sci. Technol., 37(4–5), 307–315.
35.
Jorand, F., Zartarian, F., Thomas, F., Block, J. C., and Bottero, J. Y. (1995). “Chemical and structural linkage between bacteria within activated sludge flocs.” Water Res., 29(6), 1639–1647.
36.
Kato, A., Isaka, K., and Takahashi, H. (1971). “Floc forming bacteria isolated from activated sludge.” J. General Applied Microbiol., 17(3), 439–457.
37.
Kim, D. S., and Fagler, H. S. (1999). “The effects of exopolymers on cell morphology and culturability of leuconostoc mesenteroides during starvation.” Appl. Microbiol. Biotechnol., 52, 839–844.
38.
Laspidou, C. S., and Rittmann, B. E. (2002). “Non steady-state modeling of extracellular polymeric substances, soluble microbial products, and active and inert biomass.” Water Res., 36(6), 1983–1992.
39.
Lau, A. O., Storm, P. F., and Jenkins, D. (1992). “Growth kinetics of Sphaèrotilus species and their significance in activated sludge bulking.” J. Water Pollut. Control Fed., 57, 58–79.
40.
Liao, B. Q., Allen, D. G., Droppo, I. G., Leppard, G. G., and Liss, S. N. (2001). “Surface properties of sludge and their role in bioflocculation and settleability.” Water Res., 35(9), 339–350.
41.
Liu, Y., Lam, M. C., and Fang, H. H. P. (2001). “Adsorption of heavy metals by EPS of activated sludge.” Water Sci. Technol., 43(6), 59–66.
42.
Lowry, O. H., Resebrough, N. J., Farr, A. L., and Randall, R. J. (1951). “Protein measurement with the folin phenol reagent.” J. Biol. Chem., 193, 265–275.
43.
Lysis-Tsuneda, S., Park, H., Hayashi, J., and Hirata, A. (2001). “Enhancement of nitrifying biofilm formation using selected EPS produced by heterotrophic bacteria.” Water Sci. Technol., 43(6), 197–204.
44.
Mikkelsen, L. H., Gotfredsen, A. K., Agerbaek, M. A., Nielsen, P. H., and Keiding, K. (1996). “Effects of colloidal stability on clarification and dewatering of activated sludge.” Water Sci. Technol., 34(3–4), 449–457.
45.
Morgan, J. W., Forster, C. F., and Evison, L. (1990). “A comparative study of the nature of biopolymers extracted from anaerobic and activated sludges.” Water Res., 24, 743–750.
68.
Neidhardt, R.C., Ingraham, J.L., and Schaehter, M. ( 1990). Physiology of the bacterial cell: A molecular approach, Sinaver Associates, Inc.
46.
Nielsen, P. H., Frolund, B., and Keiding, K. (1996). “Changes in exopolymer composition by anaerobic storage of activated sludge.” Appl. Microbiol. Biotechnol., 44, 823–830.
47.
Nielsen, P.H., and Jahn, A. ( 1999). “Extraction of EPS. in Microbial extracellular polymeric substances: characterization, structure and function.” Microbial extracellular substances, J. Wingender, T. R. Neu, and H. C. Fleming, eds., Springer, Berlin, 45–87.
48.
Noguera, D. R., Araki, N., and Rittmann, B. L. (1994). “Soluble microbial products in anaerobic chemostats.” Biotechnol. Bioeng., 44, 1040–1047.
49.
Novak, J. T., and Haugan, B. E. (1981). “Polymer extraction from activated sludge.” J. Water Pollut. Control Fed., 53, 1420–1424.
50.
Pavoni, J. L., Tenney, M. W., and Echelberger, W. F. (1972). “Bacterial extracellular polymers and biological flocculation.” J. Water Pollut. Control Fed., 44, 414–431.
51.
Pere, J., Alen, R., Viikari, L., and Eriksson, L. (1993). “Characterization and dewatering of activated sludge from the pulp and paper industry.” Water Sci. Technol., 28(7), 193–201.
52.
Pierzo, V., Bellahcen, D., Fontuielle, D., Lazarova, V., and Huyard, A. (1994). “Improved procedure for wastewater biofilm removal and analysis.” Colloids Surf., B, 2(12), 577–584.
53.
Rachwal, A.J., Jhonstone, W.M., Hanbury, M.J., and Critchard, D.J. ( 1982). “The application of settleability tests for the control of activated sludge plants.” Bulking of activated sludge: preventative and remedial methods, B. Chambers and E. J. Thomson, eds., Ellis Horwood Limited, Chichester, U.K., 224–242.
54.
Rittmann, B.E., and McCarty, P.L. ( 2001). Environmental biotechnology: Principles and applications, McGraw-Hill, New York.
55.
Ryan, T.A., Joiner, B.L., and Ryan, B.F. ( 1982). Minitab manual, Pennsylvania State University Press, University Park, Pa.
56.
Saby, S., Sibille, I., Mathiew, L., Paquin, J. L., and Block, J. C. (1999). “Influence of water chlorination on the counting of bacteria with DAPI(4,6-diamidino-2-phenylindole).” Appl. Environ. Microbiol., 63(6), 1564–1569.
57.
Scatt, J. A., and Karanjkar, L. (1998). “Immobilized biofilms on granular activated carbon for removal and accumulation of heavy metals from contaminated streams.” Water Sci. Technol., 38(2), 197–204.
58.
Shin, H. S., Kang, S. T., and Nam, S. Y. (2001). “Effect of carbohydrate and protein in the EPS on sludge settling characteristics.” Water Sci. Technol., 43(6), 193–196.
59.
Smith, J. K., and Vesiland, P. A. (1995). “Dilatometric measurements of bound water in wastewater sludge.” Water Res., 29(8), 2621–2626.
60.
Stewart, D. J. (1962). “A selective-diagnostic medium for the isolation of pectinolytic organisms in the Enterobacteriaceae.” Nature (London), 195 (4845), 1023–1045.
61.
Stratton, H., Seviour, B., and Brooks, P. (1998). “Activated sludge foaming what causes hydrophobicity and can it be manipulated to control foaming.” Water Sci. Technol., 37(4–5), 503–509.
62.
Sudhır, N.M. ( 1998). “Bioflocculation: Implications for activated sludge properties and wastewater treatment.” PhD thesis, Virginia Polytechnic Institute and State Univ., Blacksburg, Va.
63.
Sudhır, N. M., and Novak, J. T. (1998). “Effects of potassium ion on sludge settling, dewatering and effluent properties.” Water Sci. Technol., 37(4–9), 317–324.
64.
Tchobanoglous, G., and Schroeder, E.D. ( 1985). Water quality: Characteristics, modelling, modification, Addison-Wesley, Reading, Mass.
65.
Urbain, V., Block, J. C., and Manem, J. (1993). “Bioflocculation in activated sludge: an analytical approach.” Water Res., 27(5), 829–838.
66.
Vallom, J. K., and McLoughlin, A. J. (1984). “Lysis as a factor in sludge flocculation.” Water Res., 18(6), 1525–1528.
67.
Vincent, L., and Portaels, F. (1992). “Proposed minimal standards for the genus Mycobacterium and for description of new slowly growing Mycobacterium species.” Int. J. Syst. Bacteriol., 42(9), 315–323.
Information & Authors
Information
Published In
Journal of Environmental Engineering
Volume 130 • Issue 11 • November 2004
Pages: 1289 - 1300
Copyright
Copyright © 2004 ASCE.
History
Published online: Nov 1, 2004
Published in print: Nov 2004
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.