A review of the properties of biosludge and its relevance to enhanced dewatering processes

Biomass and Bioenergy

Volumn 58, Issue , 2013, Pages 365-378

  Mowla, D ^a   Tran, H N ^b   Allen, D Grant ^b  

^a SHIRAZ UNIVERSITY   (Iran)

^b UNIVERSITY OF TORONTO   (Canada)

Author keywords

Chemical pretreatment; Enzymatic pretreatment; Physical pretreatment; Sludge dewatering; Sludge pretreatment

Indexed keywords

CHEMICAL PRE-TREATMENT; ENZYMATIC PRETREATMENT; PHYSICAL PRE-TREATMENT; SLUDGE DEWATERING; SLUDGE PRETREATMENT;

ENVIRONMENTAL IMPACT;

DEWATERING;

DEWATERING; DOMINANCE; ENERGY EFFICIENCY; ENVIRONMENTAL IMPACT; ENVIRONMENTAL ISSUE; LITERATURE REVIEW; POLYMER; SLUDGE; WASTEWATER; WATER TREATMENT;

EID: 84888848775     PISSN: 09619534     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.biombioe.2013.09.002     Document Type: Review

References (137)

1. Yin X., Han P., Lu X., Wang Y. A review on the dewaterability of bio-sludge and ultrasound pretreatment. Ultrason Sonochem 2004, 11:337-348.
2. Elliott A., Mahmood T. Pretreatment technologies for advancing anaerobic digestion of pulp and paper biotreatment residues. Water Res 2007, 41(19):4273-4286.
3. Wang W., Lud Y., Qiao W. Possible solutions for sludge dewatering in China. Front Environ Sci Eng China 2010, 4(1):102-107.
4. CANMET Energy Technology Centre Pulp and paper sludge to energy-preliminary assessment of technologies March 2005, 152. ADI Limited, Canada, Report No. 34, 0173-479.1.
5. Lee D.J., Hsu Y.H. Measurement of bound water in sludges: a comparative study. Water Environ Res 1995, 67(3):310-317.
6. Vesilind P.A., Hsu C.C. Limits of sludge dewatering. Water Sci Technol 1997, 36(11):87-91.
7. Colin F., Gazbar S. Distribution of water in sludges in relation to their mechanical dewatering. Water Res 1995, 29(8):2000-2005.
8. Dieude-Fauvel E., Dental S.K. Sludge conditioning: impact of polymers on floc structure. J Residual Sci Technol 2011, 8(3):101-108.
9. Chu P.C., Lee D.J. Moisture distribution in sludge: effects of polymer conditioning. Environ Eng 1999, 125(14):340-345.
10. Chu C.P., Lee D.J., Chang C.Y. Energy demand in sludge dewatering. Water Res 2005, 39:1858-1868.
11. Qi Y., Thapa K.B., Hoadley A.F.A. Application of filteration aids for improving sludge dewatering properties-a review. Chem Eng J 2011, 171:373-384.
12. Thapa K.B., Qi Y., Clayton S.A., Hoadley A.F.A. Lignite aided dewatering of digested sewage sludge. Water Res 2009, 43:623-634.
13. Chen Ch, Zhang P., Zeng G., Deng J., Zhou Y., Lu H. Sewage sludge conditioning with coal fly ash modified by sulfuric acid. Chem Eng Journal 2010, 158:616-622.
14. Wang S., Viraraghavan T. Wastewater sludge conditioning by fly ash. Waste Manag 1997, 17(7):443-450.
15. Zall J., Galil N., Rehbun M. Skeleton builders for conditioning oily sludge. Water Pollut Control Fed 1987, 59(7):600-706.
16. Zhao Y.Q. Involvement of gypsum (Ca SO4.2H2O) in water treatment sludge dewatering: a potential benefit in disposal and reuse. Separation Sci Technol 2006, 41(12):2785-2794.
17. Zhao Y.Q. Enhancement of alum sludge dewatering capacity by using gypsum as skeleton builder. Colloids Surf A 2002, 211:205-212.
18. Lin Y.F., Jing S.R., Lee D.Y. Recycling of wood chips and wheat dregs for sludge processing. Bioresour Technol 2001, 76:161-163.
19. Srivastava V.C., Mall I.D., Mishra I.M. Treatment of pulp and paper mill wastewaters with polyaluminium chloride and bagasse fly ash. Colloids and Sur A 2005, 260:17-28.
20. Benitez J., Rodriguez A., Suarez A. Optimization technique for sewage sludge conditioning with polymer and skeleton builders. Water Res 1994, 28(10):2067-2073.
21. Hirota M., Okada H., Misaka Y., Kato K. Dewatering of organic sludge by pulverized coal. Water Pollut Control Fed 1975, 47(12):2774-2782.
22. Lee D.Y., Lin Y.F., Jing Z., Xu J. Effects of agricultural waste on the sludge conditioning. J China Inst Environ Eng 2001, 11:209-214.
23. Cousin C.P., Ganczarczyk J.J. The effect of cationic salt addition on the settling and dewatering properties of an industrial activated sludge. Water Environ Res 1999, 71(2):251-254.
24. Ward R.F., Huston B. Wastewater sludge dewatering for Champion-Hamilton treatment facility. Water Sci Technol 1999, 40(11-12):155-162.
25. Lee C.H., Liu J.C. Enhancement sludge dewatering by dual polyelectrolytes conditioning. Water Res 2000, 34(18):4430-4436.
26. Bache D.H., Papavasilopoulos E.N., Rasool E., Zhao Y.Q. Polymers in alum sludge dewatering: development and control. Water Environ J 2003, 17(2):106-110.
27. Jing S.R., Lin Y.F., Lin Y.M., Hsu C.S., Huang C.S., Lee D.Y. Evaluation of effective conditioners for enhancing sludge dewatering and subsequent detachment from filter cloth. J Environ Sci Health 1999, 34(7):1517-1531.
28. Bolto B., Gregory J. Organic polyelectrolytes in water treatment. Water Res 2007, 41:2301-2324.
29. Banerjee S. Sludge dewatering with cyclodextrins: a new cost effective approach. Thirteenth international water technology conference IWTC 13 March 2009, 395-401. Hurghada, Egypt.
30. Banerjee S., inventor; Georgia Tech Research Corporation, assignee. Method for improving the consolidation and dewatering of suspended particulate matter. United States patent US2008/0135194. 2008 Jun 12.
31. Hartong B.H., Abu-Daabes M., Le T., Saidan M., Banerjee S. Sludge dewatering with cyclodextrins. Water Res 2007, 41:1201-1206.
32. Park K.Y., Ahn K.H., Maeng S.K., Hwang J.H., Kwon J.H. Feasibility of sludge ozonation for stabilization and conditioning. Ozone Sci Eng 2003, 25(1):73-80.
33. 2) of sewage sludge. J Hazard Mater 2003, B98:91-96.
34. Buyukkamaci N. Biological sludge conditioning by Fenton's reagent. Process Biochem 2004, 39:1503-1506.
35. Dewil R., Baeyens J., Neyens E. Fenton peroxidation improves the drying performance of waste active sludge. J Hazard Mater 2005, B117:161-170.
36. Bohm N., Kulicke W.M. Optimization of the use of polyelectrolytes for dewatering industrial sludges of various origins. Colloid Polym Sci 1997, 275:73-81.
37. Raszka A., Chorvatova M., Wanner J. The role and significance of extracellular polymers in activated sludge. Part I: literature review. Acta Hydrochim Hydrobiol 2006, 34:411-424.
38. Wanner J. Activated sludge bukling and foaming control 1994, Technomic Publishing Co Inc., PA, USA.
39. Keiding K., Wybrandt L., Nielson P.H. Remember the water: comment on EPS colligative properties. Water Sci Technol 2001, 43:17-23.
40. Nielson P.H., Jahn A. Extraction of EPS. Microbial extracellular substances: characterization, structure and function 1999, 49-72. Springer-Verlag, Berlin Heidelberg, Chapter3. J. Wingender, T.R. Neu, H.C. Flemmin (Eds.).
41. Laspidou C.S., Rittman B.E. A unified theory for extracellular polymeric substances, soluble microbial products, and active and inert biomass. Water Res 2002, 36:2711-2720.
42. Nelson T.C., Huang J.Y.C., Ramaswami D. Decomposition of exopolysaccharide slim by a bacterio phage enzyme. Water Res 1998, 22(9):1185-1188.
43. Lu J., Rao S., Le T., Mora S., Banerjee S. Increasing cake solids of cellulosic sludge through enzyme assisted dewatering. Process Biochem 2011, 46:353-354.
44. Pei H., Hu W., Lia Q. Effect of protease and cellulase on the characteristic of activated sludge. J Hazard Mater 2010, 178:397-403.
45. Frolund B., Griebe T.T., Nielson P.H. Enzymatic activity in activated-sludge floc matrix. Appl Microbiol Biotechnol 1995, 43(4):755-761.
46. Thomas N., Rolf K. Change of particle structure of sewage sludge during mechanical and biological processes with regard to the dewatering results. Water Sci Technol 1997, 35(4):293-307.
47. Chen Y., Yang G.G. Effect of acid and surfactant treatment on activated sludge dewatering and settling. Water Res 2001, 35(11):2615-2620.
48. Kumar Khanal S., Grewell D., Sung S., Leeuwen J.V. Ultrasonic applications in wastewater sludge pretreatment: a review. Crit Rev Environ Sci Technol 2007, 37:277-313.
49. Rokhina E.V., Lens P., Virkutyte J. Low-frequency ultrasound in biotechnology: state of the art. Trends Biotechnol 2009, 27(5):298-306.
50. Wang F., Ji M., Lu S. Influence of ultrasonic disintegration on the dewaterability of waste activated sludge. Environ Prog 2006, 25(3):257-260.
51. Huan L., Yiying J., Mahar R.B., Zhiyu W., Yongfeng N. Effects of ultrasonic disintegration on sludge microbial activity and dewaterability. J Hazard Mater 2009, 161:1421-1426.
52. Pilli S., Bhunia P., Yan S., LeBlac R.J., Tyagi R.D., Surampalli R.Y. Ultrasonic pretreatment of sludge: a review. Ultrason Sonochem 2011, 18:1-18.
53. Khanal S.K., Isik H., Sung S., van Leeuwen J. Ultrasonic conditioning of waste activated sludge: evaluation of sludge disintegration and aerobic digestibility. Proceeding of IWA world water congress and exhibition 10-14 September 2006, Beijing, China.
54. Khanal S.K., Isik H., Sung S., van Leeuwen J. Ultrasonic conditioning of waste activated sludge for enhanced aerobic digestion. Proceedding of IWA specialized conference-sustainable sludge management: state of the art, challenges and perspectives 29-31 May 2006, Moscow, Russia.
55. Khanal S.K., Isik H., Sung S., van Leeuwen J. Effect of ultrasonic pretreatment on aerobic digestibility of thickened waste activated sludge. Proceedding of 7th specialized conference on small water and wastewater systems 7-10 March 2006, Mexico City, Mexico.
56. Wang F., Shan L., Ji M. Components of released liquid from ultrasonic waste activated sludge disintegration. Ultrason Sonochem 2006, 13(4):334-338.
57. Rai C.L., Struenkmann G., Muller J., Rao P.G. Influence of ultrasonic disintegration on sludge growth and its estimation by respirometry. Environ Sci Technol 2001, 38:5779-5785.
58. Tuncal T. Improving thermal dewatering characteristics of mechanically dewatered sludge: response surface analysis of combined lime-heat treatment. Water Environ Res 2011, 83(5):405-410.
59. Vlyssidea A.G., Karlis P.K. Thermal-alkaline solubilization of waste activated sludge as a pre-treatment stage for anaerobic digestion. Bioresour Technol 2004, 91:201-206.
60. Dental S.K. Conditioning, thickening, and dewatering: research update/research needs. Water Sci Technol 2001, 44(10):9-18.
61. Laheij E.J., Kerkhof P.J.A.M., Herwijn A.J.M., Cumans W.J. Fundamental aspects of sludge filteration and expression. Water Res 1996, 30(3):697-703.
62. Zhao Y.Q., Bache D.H. Integrated effects of applied pressure, time and polymer doses on alum sludge dewatering behavior. Waste Manag 2002, 22:813-819.
63. Chun Y.N., Lim M.S., Yoshikawa K. Development of a high efficiency rotary dryer for sewage sludge. J Mater Cycles Waste Manag 2012, 14:65-73.
64. Mowla D. Simulation of fluidized bed driers. Proceeding of CHISA96 conference 1996, Prague, Czech Republic.
65. Adamiec J. Drying of waste sludges in a fluidized bed dryer with a mixer. Drying Technol 2002, 20(4-4):839-853.
66. Shin Y.S., Kim H.C., Chun H.S. Drying of water treatment process sludge in a fluidized bed dryer. Korean J Chem Eng 2000, 17(1):22-26.
67. Velegol D., Feick J.D., Collins R.L. Electrophoresis of spherical particles with a random distribution of zeta potential or surface charge. J Colloid Interface Sci 2000, 230:114-121.
68. Lotito V., Spinosa L., Mininni G. The rheology of sewage sludge at different steps of treatment. Water Sci Technol 1997, 36(11):79-85.
69. Huisman M., van Kesteren W.G.M. Consolidation theory applied to the capillary suction time (CST) apparatus. Water Sci Technol 1998, 37(6-7):117-124.
70. Ruth B.F. Correlating filteration theory with industrial practice. J Ind Eng Chem 1946, 38:564-571.
71. Arhan Y., Zoturk I., Ciftci T. Settling and dewatering characteristics of sludge from baker's yeast production wastewater treatment. Water Sci Technol 1996, 34(3-4):459-467.
72. Wingender J., Neu T., Flemming H.C. What are bacterial extracellular polymeric substances?. Microbial extracellular substances: characterization, structure and function 1999, 1-18. Springer-Verlag, Berlin Heidelberg, [Chapter 1]. J. Wingender, T.R. Neu, H.C. Flemmin (Eds.).
73. Liu Y., Fang H.P. Influence of extracellular polymeric substances (EPS) on flocculation, settling, and dewatering of activated sludge. Crit Rev Environ Sci Technol 2003, 33:237-273.
74. Frolund B., Palmgren R., Keiding K., Nielson P.H. Extraction of extracellular polymers from activated sludge using a cation exchange resin. Water Res 1996, 30:1749-1758.
75. Sheng G.P., Yu H.Q., Li X.Y. Extracellular polymeric substances (EPS) of microbial aggregates in biological wastewater treatment systems: a review. Biotechnol Advances 2010, 28:882-894.
76. Dignac M.F., Urbain V., Rybacki D., Bruchet A., Snidaro D., Scribe P. Chemical description of extracellular polymeric substances: implication on activated sludge floc structure. Water Sci Technol 1998, 38:45-53.
77. D'Abzac P., Bordas F., Joussein E., van Hullebusch E., Lens P.N.L., Guibaud G. Characterization of the mineral fraction associated to extracellular polymeric substances (EPS) in anaerobic granular sludge. Environ Sci Technol 2010, 44:412-418.
78. D'Abzac P., Bordas F., van Hullebusch E., Lens P.N.L., Guibaud G. Extraction of extracellular polymeric substances (EPS) from anaerobic granular sludges: comparison of chemical and physical extraction protocols. Appl Microbiol Biotechnol 2010, 46:197-201.
79. 4 producing granules. Water Res 2006, 40:1811-1815.
80. Zheng Y.M., Yu H.Q. Determination of the pore size distribution and porosity of anaerobic granules using size exclusion chromatograph. Water Res 2007, 41:39-46.
81. Wilen B.M., Jin B., Lant P. The influence of the key chemical constituents in activated sludge on surface and flocculation properties. Water Res 2003, 37:2127-2130.
82. Liao B.Q., Allen D.G., Leppard G.G., Droppo I.G., Liss S.N. Interparticle interactions affecting the stability of sludge flocs. J Colloid Interface Sci 2002, 249:372-380.
83. Wang Z.W., Liu Y., Tay J.Y. Distribution of EPS and cell surface hydrophobicity in aerobic granules. Appl Microbiol Biotechnol 2005, 69:469-473.
84. Jin B., Wilen B.M., Lant P.A. Comprehensive insight into floc characteristics and their impact on compressibility and settleability of activated sludge. Chem Eng J 2003, 95:221-234.
85. Yang S.F., Li X.Y. Influence of extracellular polymeric substances (EPS) on the characteristics of activated sludge under non-steady state conditions. Process Biochem 2009, 44:91-96.
86. Mogan J.W., Forster C.F., Evison L. A comparative study of the nature of biopolymers extracted from anaerobic and activated sludges. Water Res 1990, 24:743-753.
87. Liu X.M., Sheng G.P., Yu H.Q. DLVO approach to the floccubility of a photosynthetic H2-producing bacterium. Rhodopseudomonas acidophila. Environ Sci Technol 2007, 41:4620-4625.
88. Liu X.M., Sheng G.P., Yu H.Q., Luo H.W., Zhang F., Yuan S.J., et al. Contribution of extracellular polymeric substances (EPS) to the sludge aggregation. Environ Sci Technol 2010, 44:4355-4360.
89. Comte S., Guibaud G., Bandu M. Effect of extraction method on EPS from activated sludge: an HPSEC investigation. J Hazard Mater 2007, 140:129-137.
90. Ahn K.H., Kim K.S., Kang S.W., Um C.Y., Lee W.T., Ko K.B. Settling and dewatering characteristics of granulated methane-oxidizing bacteria. J Environ Sci 2012, 10.1016/S1001-0742(12)60021-7.
91. Houghton J., Quarmby J., Stephenson T. Municipal wastewater sludge dewatering and the presence of microbial extracellular polymer. Water Sci Technol 2001, 44(2):373-379.
92. Neyens E., Baeyens J., Dewil R., de heyder B. Advanced sludge treatment affects extracellular polymeric substances to improve activated sludge dewatering. J Hazard Mater 2004, 106:83-92.
93. Chen Y., Yang H., Gu G. Effect of acid and surfactant treatment on activated sludge dewatering and settling. Water Res 2001, 35:2615.
94. Houghton J., Stephenson T. Effect of influent organic content on digested sludge extracellular polymer content and dewaterability. Water Res 2002, 36:3620-3628.
95. Coumans W.J., Kerkhof P.J.A.M. The solid-water bound strength in sewage sludge. AIChE annual meeting, Miami Beach, Fla 1992, 1073-1078.
96. Robinson J., Knocke W.R. Use of dilatometric and drying techniques for assessing sludge dewatering characteristics. Water Environ Res 1992, 64(1):60-68.
97. Smith K.J., Vesilind P.A. Dilatometric measurement of bound water in wastewater sludge. Water Res 1995, 29(12):2621-2626.
98. Katsiris N., Kouzeli-Katsiri A. Bound water content of biological sludges in relation to filtration and dewatering. Water Res 1987, 21:1319-1327.
99. Lee H.B., Jhon M.S., Anderson J.D. Nature of water in synthetic hydrogels. J Colloid Interface Sci 1975, 51:225.
100. Lee D.J., Lee S.F. Measurement of bound water content in sludge: use of differential scanning calorimetry (DSC). J Chem Tech Biotechnol 1995, 62:359-365.
101. Haschemeyer A.E.V., Guschlbauer W., Devries A.L. Water binding by antifreeze glycoproteins from Antarctic fish. Nature 1977, 269:87-88.
102. Lewicki P.P., Busk G.C., Labuza T.P. Measurment of gel-water binding capacity of gelatin, potato starch and carrageenan gels by suction pressure. J Colloid Interface Sci 1978, 64:501-509.
103. Lee D.J. Measurment of bound water in waste activated sludge: use of the centrifugal settling method. J Chem Tech Biotechnol 1994, 63:139-144.
104. Tay J.H., Jeyaseelan S. Comparison of lime and alum as oily sludge conditioners. Water Sci Technol 1997, 35(12):117-124.
105. Gogate P.R., Kabadi A.M. A review of application of cavitation in biochemical engineering/biotechnology. Biochem Eng 2009, 44:60-72.
106. Bien J., Wolny L. Changes of some sewage sludge parameters prepared with an ultrasonic field. Water Sci Technol 1997, 36(11):101-106.
107. Hogan F., Mormede S., Clark P., Crane M. Ultrasonic sludge treatment for enhanced aerobic digestion. Water Sci Technol 2004, 50(9):25-32.
108. Feng X., Deng J., Lei H., Bai T., Fan Q., Li Z. Dewatering of waste activated sludge with ultrasonic conditioning. Bioresour Technol 2009, 100:1074-1081.
109. Gogate P.R., Pandit A.B. Hydrodynamic cavitation reactors: a state of the art review. Rev Chem Eng 2001, 17(1):1-85.
110. Caufield P. Unlocking the value in sludge. Pulp Paper Can May/June 2012, 18-19.
111. Vesilind P.A., Wallinmaa S., Martel C.J. Freeze-thaw sludge conditioning and double layer compression. Can J Civ Eng 1991, 18:1078-1083.
112. Jean D.S., Chu C.P., Lee D.J. Freeze/thaw treatment of oily sludge from petroleum refinery plant. Separation Sci Technol 2001, 36(12):2733-2746.
113. Martel C.J. Fundamentals of sludge dewatering in freezing beds. Water Sci Technol 1993, 28(1):29-35.
114. Vesilind P.A., Martel C.J. Freezing of water and wastewater sludges. J Environ Eng Am Soc Civil Eng 1990, 116(5):854-862.
115. Hellstrom D., Kvarnstrom E. Natural sludge dewatering. I: combination of freezing, thawing, and drying as dewatering methods. J Cold Regions Eng 1997; March, 1-14.
116. Ormeci B. Freeze-thaw conditioning of activated sludge: effect of monovalent, divalent and trivalent cations. J Residuals Sci Technol 2004, 1(3):143-150.
117. Franceschini O. Dewatering of sludge by freezing 2010, Master thesis, Civil and Mining Engineering, Lulea University of Technology.
118. Martel C.J., Diener C. Pilot-scale studies of sludge dewatering in a freezing bed. Can J Civ Eng 1991, 18:681-689.
119. Abu-Orf M.M., Dentel S.K. Automatic control of polymer dose using the measuring current detector. Water Environ Res 1998, 70:1005-1018.
120. Wang Y., Banerjee S. Cyclodextrins modify the properties of cationic polyacrylamides. J Colloid Interface Sci 2009, 339:325-329.
121. Perng Y.S., Wang C., Yu S.T., Gong H.U., Dineh L., Kuo L.S. Application of nano-silica to paper mill sludge dewatering. Taiwan J Sc 2006, 21(3):353-362.
122. Zhao Y.Q., Koegh C., Maha A.T. On the necessity of sludge conditioning with non-organic polymer: AOP approach. J Residuals Sci Technol 2009, 6(3):151-155.
123. Shihab M.S. Assessment of using chemical coagulants and effective microorganisms in sludge dewatering process improvement. J Environ Sci Technol 2010, 3(1):35-46.
124. Ayol A., Dental S.K. Enzymatic treatment effects on dewaterability of anaerobically digested biosolids- II: laboratory characteristics of drainability and filterability. Proc Biochem 2005, 40:2435-2442.
125. Abu- Orf M., Dental S., Dursun D., Turkmen M. Pilot-scale evaluation of enzyme pre-treatment to enhance dewatering: effects of shear and polymer. WEF/AWWA joint residuals and biosolids management conference, April 15-18, 2007 2007, 1180-1195. Water Environment Federation, Denver, CO, USA.
126. Thomas L., Jungschaffer G., Sprossler B. Improved sludge dewatering by enzymatic treatment. Water Sci Technol 1993, 28(1):189-192.
127. Sarkar J, Shah J, Ramesh M. Method of dewatering sludge using enzymes, United State Patent, US 6733673B2. 2004.
128. Wawrzynczk J., Szewczyk E., Norrlow O., Szwajcer Dey E. Application of enzymes, sodium tripolyphosphate and cation exchange resin for the release of extracellular polymeric substances from sewage sludge. Characterization of the extracted polysaccharides/glycoconjugates by a panel of lectins. J Biotechnol 2007, 130:274-281.
129. Ayol A. Enzymatic treatment effects on dewaterability of anaerobically digested biosolids- I: performance evaluations. Proc Biochem 2005, 40:2427-2434.
130. Parmer N., Singh A., Ward O.P. Enzyme treatment to reduce solids and improve settling of sewage sludge. J Ind Microbiol Biotechnol 2001, 26:383-386.
131. Dursun D., Turkmen M., Abu-Orf M., Dental S.K. Enhanced sludge conditioning by enzyme pre-treatment: comparison of laboratory and pilot scale dewatering results. Water Sci Technol 2006, 54(5):33-41.
132. Lu J., Reye J., Banerjee S. Temperature dependence of cellulose hydrolysis of paper fibber. Biomass Bioenergy 2010, 34:1973-1977.
133. Buyukkamaci N., Kucukselek E. Improvement of dewatering capacity of a petrochemical sludge. J Hazard Mater 2007, 144:323-327.
134. Hou C.H., Li K.C. Assessment of sludge dewatering using rheological properties. J Chinese Inst Eng 2003, 26(2):221-226.
135. Tony M.A., Zhao Y.Q., Fu J.F., Tayeb A.M. Conditioning of aluminium-based water treatment sludge with Fenton's reagents: effectiveness and optimizing study to improve dewaterability. Chemosphere 2008, 72:673-677.
136. Neyens E., Baeyens J. A review of thermal sludge pre-treatment processes to improve dewaterability. J Hazard Mater 2003, B98:51-67.
137. Saha M., Eskicioglu C., Marin J. Microwave, ultrasonic and chemo-mechanical pretreatment for enhancing methane potential of pulp mill wastewater treatment sludge. Bioresour Technol 2011, 102:7815-7826.