Tetra-detector size exclusion chromatography characterization of molecular and solution properties of soluble microbial polysaccharides from an anaerobic membrane bioreactor

Characterization of the molecular properties of soluble microbial products （SMP） is critical for understanding the membrane filtration and fouling mechanisms in anaerobic and aerobic membrane bioreactors （AnMBR ＆ MBR）. In this study, the distributions of the absolute molecular weight and intrinsic viscosity of SMP polysaccharides from an AnMBR were effectively determined by a high pertbrmance size exclusion chromatography （HPSEC） that was coupled with the refractive index （RI）,cliode array UV （DAUV）, right and low angle light scattering （LS）, and viscometer （Vis） detectors. Based on the tetra-detector HPSEC determined absolute molecular weights and intrinsic viscosity, a universal calibration relationship for the SMP polysaccharides was developed and the molecularconformations, average molecular weights~ and hydrodynamic sizes of the SMP polysaccharides were also explored. Two factors which can be derived from the tetra-detector HPSEC analysis were proposed for the characterization of the viscous and osmotic pressure properties of the SMP polysaccharides. In addition, it was also extrapolated how to analyze the resistance characteristics of the concentration polarization layers formed in membrane filtration based on the molecular properties determined by the tetra-detector HPSEC analysis.