A review on the dewaterability of bio-sludge and ultrasound pretreatment.

Bio-sludge, which contains large quantities of water, biomass and extracellular polymeric substances (EPS), is difficult to be dewatered as a "super-compactable" sludge [Water Res. 35 (5) (2001) 1358]. Reported water content in bio-sludge was commonly about 80-90% wt after dewatering process. The EPS and the form of water in sludge influences the structure of sludge. Adding cationic fluctuations can change the form of water in sludge and increase the velocity of dewatering process, but has little influence on the final water content. According to Bien's work [Water Sci. Technol. 36 (4) (1997) 287], a combination of ultrasound or other method could agglomerate the sludge, improve the activities of biomass [Ultrasonics 38 (2000) 711; Ultrasonics 40 (2002) 25], enhance anaerobic process [Water Sci. Technol. 36 (11) (1997) 155; Water Sci. Technol. 36 (11) (1997) 121; Water Res. 35 (8) (2001) 2003; Water Sci. Technol. 36 (12) (1997) 117] and decrease over 10% final water content of sludge. The mechanisms of ultrasonic influence on sludge are not very clear, but the application of ultrasound to industrial process is relatively easy and possible.

[1]  A. Tiehm,et al.  Ultrasonic waste activated sludge disintegration for improving anaerobic stabilization. , 2001, Water research.

[2]  J. Darby,et al.  Extracellular polyanions in digested sludge: Measurement and relationship to sludge dewaterability , 1997 .

[3]  Collins,et al.  Electrophoresis of Spherical Particles with a Random Distribution of Zeta Potential or Surface Charge. , 2000, Journal of colloid and interface science.

[4]  P. Parker,et al.  Ultra-rapid freezing of water treatment residuals , 1999 .

[5]  P. Aarne Vesilind,et al.  Synthetic sludge : A physical/chemical model in understanding bioflocculation , 1996 .

[6]  Mohammad Abu-Orf,et al.  Laboratory and full-scale studies of liquid stream viscosity and streaming current for characterization and monitoring of dewaterability , 1995 .

[7]  M. Özacar.  Effectiveness of tannins obtained from valonia as a coagulant aid for dewatering of sludge , 2000 .

[8]  L. Mikkelsen,et al.  The shear sensitivity of activated sludge , 2001 .

[9]  J. Yvon,et al.  Ferric chloride and lime conditioning of activated sludges: an electron microscopic study on resin-embedded samples. , 2001, Water research.

[10]  F. Colin,et al.  Distribution of water in sludges in relation to their mechanical dewatering , 1995 .

[11]  J. Schmitt,et al.  Water binding in biofilms , 1999 .

[12]  D. J. Lee,et al.  Capillary suction time (CST) as a measure of sludge dewaterability , 1996 .

[13]  C. Wan,et al.  Conditioning characteristics of kaolin sludge with different cationic polyelectrolytes , 1998 .

[14]  C. Forster,et al.  The use of ultrasound and gamma-irradiation as pre-treatments for the anaerobic digestion of waste activated sludge at mesophilic and thermophilic temperatures. , 2002, Bioresource technology.

[15]  K. Keiding,et al.  On the Stability of Activated Sludge Flocs with Implications to Dewatering , 1992 .

[16]  F. Clauss,et al.  Improving activated sludge floc structure and aggregation for enhanced settling and thickening performances , 1998 .

[17]  C. Chu,et al.  Experimental analysis of centrifugal dewatering process of polyelectrolyte flocculated waste activated sludge. , 2001, Water research.

[18]  C. Martel.  Influence of dissolved solids on the mechanism of freeze-thaw conditioning , 2000 .

[19]  Riera-Franco de Sarabia E,et al.  Application of high-power ultrasound to enhance fluid/solid particle separation processes , 2000, Ultrasonics.

[20]  P. Aarne Vesilind,et al.  Freezing of Water and Wastewater Sludges , 1990 .

[21]  S. Edward Law,et al.  Electroosmotically enhanced drying of biomass , 1997 .

[22]  Piet J. A. M. Kerkhof,et al.  Fundamental aspects of sludge filtration and expression , 1996 .

[23]  Izzet Ozturk,et al.  Settling and dewatering characteristics of sludge from baker's yeast production wastewater treatment , 1996 .

[24]  J. C. Liu,et al.  Sludge dewaterability and floc structure in dual polymer conditioning , 2001 .

[25]  R. Audebert,et al.  Deswelling and flocculation of gel networks : Application to sludge dewatering , 1998 .

[26]  D. Bache,et al.  Conditioning of alum sludge with polymer and gypsum , 2001 .

[27]  Hyoe Hatakeyama,et al.  Interaction between water and hydrophilic polymers , 1998 .

[28]  M. Huisman,et al.  Consolidation theory applied to the capillary suction time (CST) apparatus , 1998 .

[29]  K. Keiding,et al.  Physico-chemical characteristics of full scale sewage sludges with implications to dewatering. , 2002, Water research.

[30]  L. Spinosa,et al.  The rheology of sewage sludge at different steps of treatment , 1997 .

[31]  J. L. Watson,et al.  Application of magnetic forces to disk vacuum filtration in the laboratory and plant , 1999 .

[32]  Change of particle structure of sewage sludges during mechanical and biological processes with regard to the dewatering result , 1997 .

[33]  Yao-de Yan,et al.  Aggregate structures formed via a bridging flocculation mechanism , 2000 .

[34]  M. Smollen,et al.  Investigation into alternative sludge conditioning prior to dewatering , 1997 .

[35]  S. Dentel,et al.  Effect of mixing on the rheological characteristics of conditioned sludge: full-scale studies , 1997 .

[36]  B. Örmeci,et al.  Development of an improved synthetic sludge: a possible surrogate for studying activated sludge dewatering characteristics , 2000 .

[37]  Per Moldrup,et al.  Filtration and expression of compressible cakes , 1996 .

[38]  Michel Perrier,et al.  Respirometric control of the anaerobic period duration of an SBR bio-P process , 1997 .

[39]  J. Novak,et al.  Monitoring cations to predict and improve activated sludge settling and dewatering properties of industrial wastewaters , 1998 .

[40]  H. N. Stein,et al.  Full scale electrokinetic dewatering of waste sludge , 2002 .

[41]  S. Duff,et al.  A laboratory sludge press for characterizing sludge dewatering , 1997 .

[42]  Jih‐Gaw Lin,et al.  Alkaline and ultrasonic pretreatment of sludge before anaerobic digestion , 1997 .

[43]  P. Nielsen,et al.  Iron reduction in activated sludge measured with different extraction techniques , 1996 .

[44]  A. Tiehm,et al.  The use of ultrasound to accelerate the anaerobic digestion of sewage sludge , 1997 .

[45]  Duu-Jong Lee,et al.  Novel cake characteristics of waste-activated sludge. , 2001, Water research.

[46]  T. Onyeche,et al.  Ultrasound stimulation of micro-organisms for enhanced biodegradation. , 2002, Ultrasonics.

[47]  Yaqian Zhao.  Correlations between floc physical properties and optimum polymer dosage in alum sludge conditioning and dewatering , 2003 .

[48]  D. Bache,et al.  Integrated effects of applied pressure, time, and polymer doses on alum sludge dewatering behaviour. , 2002, Waste management.

[49]  I. Rinard,et al.  Incorporation of rapid thermal conditioning into a wastewater treatment plant , 1998 .

[50]  Duu-Jong Lee,et al.  Observations on changes in ultrasonically treated waste-activated sludge. , 2001, Water research.

[51]  Peter Jacobsen,et al.  Artificial neural networks as a tool in urban storm drainage , 1997 .

[52]  P. Vesilind,et al.  Limits of sludge dewaterability , 1997 .

[53]  K. Keiding,et al.  Disintegration of Activated Sludge Flocs in Presence of Sulfide , 1998 .

[54]  K. Keiding,et al.  Desorption of organic macromolecules from activated sludge: Effect of ionic composition , 1997 .

[55]  Kazuhiro Tanaka,et al.  Innovative sludge handling through pelletization/thickening , 1999 .

[56]  G. Gu,et al.  Effect of acid and surfactant treatment on activated sludge dewatering and settling. , 2001, Water research.

[57]  M. Higgins,et al.  Examination of three theories for mechanisms of cation-induced bioflocculation. , 2002, Water research.

[58]  S. Jeyaseelan,et al.  Comparison of lime and alum as oily sludge conditioners , 1997 .

[59]  C. F. Forster,et al.  The rheological and physico-chemical characteristics of sewage sludges , 2002 .

[60]  January Bien,et al.  Changes of some sewage sludge parameters prepared with an ultrasonic field , 1997 .

[61]  T. Onyeche,et al.  Improvement of biological activity by low energy ultrasound assisted bioreactors. , 2000, Ultrasonics.

[62]  Jih‐Gaw Lin,et al.  Effect of pre-sonication on removal of organic matters resulting from chlorinated humic acids , 1998 .

[63]  Jill Ruhsing Pan,et al.  DEWATERING CHARACTERISTICS OF ALGAE-CONTAINING ALUM SLUDGE , 1999 .

[64]  P. Vesilind,et al.  Effect of dissolved organic material and cations on freeze-thaw conditioning of activated and alum sludges. , 2001, Water research.

[65]  J. Bień,et al.  Influence of ultrasonic field on structure and parameters of sewage sludge for dewatering process , 1997 .

[66]  T. C. Nelson,et al.  Decomposition of exopolysaccharide slime by a bacteriophage enzyme , 1988 .