Structure of cake layer in a submerged anaerobic membrane bioreactor

Abstract A laboratory-scale submerged anaerobic membrane bioreactor (SAnMBR) was used for thermomechanical pulping whitewater treatment. Sludge cake formation on membrane surfaces was identified as the dominant mechanism of membrane fouling. The spatial distribution of physical, chemical and microbiological structure of cake layers was characterized by various analytical techniques, including micro-tome slicing technique, confocal laser scanning microscopy (CLSM), conventional optical microscopy (COM), scanning electron microscopy (SEM)-energy-dispersive X-ray analyzer (EDX), particle size distribution (PSD) analysis, Fourier transform infrared (FTIR) spectroscopy, extraction and chemical analysis of extracellular polymeric substances (EPS), and polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). The results showed that the areal porosity decreased from the top layer to the bottom layer. Smaller flocs had a higher tendency to accumulate on membrane surfaces but the consolidation of cake sludge in the bottom layers resulted in larger flocs as compared to the fresh cake sludge formed on the top layers. There was an increase in the bound EPS density (mg EPS/cm3 wet sludge) and a decrease in the ratio of proteins to polysaccharides in bound EPS from the top to bottom layers. PCR-DGGE study showed that there were significant differences in microbial community population density along the cake layer depth. Through the CLSM and COM images, cake layer was found to have a loose outer surface when compared with the cake bottom. The results provide a new insight in cake layer structure and suggest that structures change significantly from the top layer to the bottom layer.

[1]  K. Keiding,et al.  Extraction of extracellular polymers from activated sludge using a cation exchange resin , 1996 .

[2]  R. Sheikholeslami,et al.  Composite fouling - inorganic and biological : A review , 1999 .

[3]  Filtration capability and operational characteristics of dynamic membrane bioreactor for municipal wastewater treatment , 2006 .

[4]  Daniel B. Oerther,et al.  Identifying pioneer bacterial species responsible for biofouling membrane bioreactors. , 2006, Environmental microbiology.

[5]  Corinne Cabassud,et al.  Comparison of sludge characteristics and performance of a submerged membrane bioreactor and an activated sludge process at high solids retention time. , 2006, Water research.

[6]  A. Livingston,et al.  Extraction and biodegradation of a toxic volatile organic compound (1,2-dichloroethane) from waste-water in a membrane bioreactor , 1994, Applied Microbiology and Biotechnology.

[7]  Fenglin Yang,et al.  Characterization of cake layer in submerged membrane bioreactor. , 2007, Environmental science & technology.

[8]  Hongjun Lin,et al.  Sludge properties and their effects on membrane fouling in submerged anaerobic membrane bioreactors (SAnMBRs). , 2009, Water research.

[9]  Haluk Beyenal,et al.  Three-dimensional biofilm structure quantification. , 2004, Journal of microbiological methods.

[10]  F. Fan,et al.  Interrelated effects of aeration and mixed liquor fractions on membrane fouling for submerged membrane bioreactor processes in wastewater treatment. , 2007, Environmental science & technology.

[11]  Raphael Semiat,et al.  Bacterial community composition and structure of biofilms developing on nanofiltration membranes applied to wastewater treatment. , 2007, Water research.

[12]  J B Xavier,et al.  Automated biofilm morphology quantification from confocal laser scanning microscopy imaging. , 2003, Water science and technology : a journal of the International Association on Water Pollution Research.

[13]  P. Schmitz,et al.  Effective hydraulic resistance of the first cake layers at the membrane surface in microfiltration , 2002 .

[14]  Daniel B. Oerther,et al.  Effect of activated sludge properties and membrane operation conditions on fouling characteristics in membrane bioreactors. , 2006, Chemosphere.

[15]  Giorgio Mannina,et al.  An integrated model for physical-biological wastewater organic removal in a submerged membrane bioreactor: Model development and parameter estimation , 2008 .

[16]  D. Stuckey,et al.  Activated Carbon Addition to a Submerged Anaerobic Membrane Bioreactor: Effect on Performance, Transmembrane Pressure, and Flux , 2007 .

[17]  Hongjun Lin,et al.  Influence of elevated pH shocks on the performance of a submerged anaerobic membrane bioreactor , 2010 .

[18]  Chihpin Huang,et al.  Behavior of Membrane Scaling During Crossflow Filtration in the Anaerobic MBR System , 2006 .

[19]  Kwang-Ho Choo,et al.  Membrane fouling mechanisms in the membrane-coupled anaerobic bioreactor , 1996 .

[20]  David M. Bagley,et al.  Anaerobic Membrane Bioreactors: Applications and Research Directions , 2006 .

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

[22]  Yoshimasa Watanabe,et al.  Membrane fouling in pilot-scale membrane bioreactors (MBRs) treating municipal wastewater. , 2005, Environmental science & technology.

[23]  X. Y. Li,et al.  Influence of loosely bound extracellular polymeric substances (EPS) on the flocculation, sedimentation and dewaterability of activated sludge. , 2007, Water research.

[24]  G. Guibaud,et al.  Relation between extracellular polymers' composition and its ability to complex Cd, Cu and Pb. , 2003, Chemosphere.

[25]  H. Spanjers,et al.  Mesophilic and thermophilic activated sludge post-treatment of paper mill process water. , 2002, Water research.

[26]  Kyung-Min Yeon,et al.  Correlating TMP increases with microbial characteristics in the bio-cake on the membrane surface in a membrane bioreactor. , 2008, Environmental science & technology.

[27]  Anthony G. Fane,et al.  Fouling transients in nominally sub-critical flux operation of a membrane bioreactor , 2002 .

[28]  Jianrong Chen,et al.  New insights into membrane fouling in a submerged anaerobic membrane bioreactor based on characterization of cake sludge and bulk sludge. , 2011, Bioresource technology.

[29]  Menachem Elimelech,et al.  Chemical and physical aspects of natural organic matter (NOM) fouling of nanofiltration membranes , 1997 .

[30]  Zhiwei Wang,et al.  Membrane fouling in a submerged membrane bioreactor (MBR) under sub-critical flux operation : Membrane foulant and gel layer characterization , 2008 .

[31]  D. Bagley,et al.  Performance and fouling characteristics of a submerged anaerobic membrane bioreactor for kraft evaporator condensate treatment , 2010, Environmental technology.

[32]  Jean-Philippe Croué,et al.  Fouling characteristics of wastewater effluent organic matter (EfOM) isolates on NF and UF membranes , 2002 .

[33]  Xiao-yan Li,et al.  Accumulation of biopolymer clusters in a submerged membrane bioreactor and its effect on membrane fouling. , 2008, Water research.

[34]  Zhichao Wu,et al.  Relationship between sludge characteristics and membrane flux determination in submerged membrane bioreactors , 2006 .

[35]  I. Chang,et al.  Effect of pump shear on the performance of a crossflow membrane bioreactor. , 2001, Water research.

[36]  Sangho Lee,et al.  The effects of intermittent aeration on the characteristics of bio-cake layers in a membrane bioreactor. , 2007, Environmental science & technology.

[37]  Giorgio Mannina,et al.  Uncertainty assessment of a membrane bioreactor model using the GLUE methodology , 2010 .

[38]  Structure of RBC biofilms , 1994 .

[39]  Jiti Zhou,et al.  Factors affecting the membrane performance in submerged membrane bioreactors , 2006 .

[40]  Menachem Elimelech,et al.  Coupling between chemical and physical interactions in natural organic matter (NOM) fouling of nanofiltration membranes: implications for fouling control , 2002 .

[41]  Tian C. Zhang,et al.  Density, porosity, and pore structure of biofilms , 1994 .

[42]  V. Ferre,et al.  A novel combination of methane fermentation and MBR — Kubota Submerged Anaerobic Membrane Bioreactor process , 2010 .

[43]  Xiao-yan Li,et al.  Membrane fouling in a membrane bioreactor (MBR): sludge cake formation and fouling characteristics. , 2005, Biotechnology and bioengineering.

[44]  Mark M. Clark,et al.  Modeling of flux decline during crossflow ultrafiltration of colloidal suspensions , 1998 .

[45]  Ulises Jáuregui-Haza,et al.  Modelling of submerged membrane bioreactor: Conceptual study about link between activated slugde biokinetics, aeration and fouling process , 2008 .

[46]  D. Jeison,et al.  Cake formation and consolidation: Main factors governing the applicable flux in anaerobic submerged membrane bioreactors (AnSMBR) treating acidified wastewaters , 2007 .

[47]  I. Chang,et al.  Correlation of biofouling with the bio-cake architecture in an MBR , 2008 .

[48]  In S. Kim,et al.  The effect of calcium on the membrane biofouling in the membrane bioreactor (MBR). , 2006, Water Research.

[49]  Steven N. Liss,et al.  Membrane fouling in a fermentative hydrogen producing membrane bioreactor at different organic loading rates , 2010 .

[50]  Hang-Sik Shin,et al.  Sludge characteristics and their contribution to microfiltration in submerged membrane bioreactors , 2003 .

[51]  A. Drews,et al.  Impact of ambient conditions on SMP elimination and rejection in MBRs. , 2007, Water research.