Characterization of Soluble Microbial Products and Their Fouling Impacts in Membrane Bioreactors

Abstract

Membrane bioreactor (MBR) fouling is not only influenced by the soluble microbial products (SMP) concentration but by their characteristics. Experiments of separate producing biomass associated products (BAP) and utilization associated products (UAP) allowed the separation of BAP and UAP effects from sludge water (SW). Thus, filtration of individual SMP components and further characterization becomes possible. Unstirred cell filtration was used to study fouling mechanisms and liquid chromatography--organic carbon detection (LC-OCD) and fluorescence excitation--emission matrix (EEM) were used to characterize the foulant. Generally, the SMP exhibiting characteristics of higher molecular weight, greater hydrophilicity and a more reduced state showed a higher retention percentage. However, the higher retention does not always yield higher fouling effects. The UAP filtration showed the highest specific cake resistance and pore blocking resistance attributed to their higher percentage of low molecular weight molecules, although their retention percentage was lower than the SW and BAP filtration. The UAP produced in the cell proliferation phase appeared to have the highest fouling potential.

Identification of proteins involved in membrane fouling in membrane bioreactors (MBRs) treating municipal wastewater

“…Attention has been given to various fractions such as utilization-associated products (UAP) (Jiang et al 2010;Tian et al 2011), biopolymer cluster (BPC) (Wang and Li 2008;Sun et al 2011), and transparent exopolymer particles (TEP) (de la Torre et al 2008). At present, however, actual contributions of these fractions to the development of membrane fouling are still unclear, and therefore, no universal fouling indicator has been proposed (Drews 2010).…”

Characterisation of reverse osmosis permeates from municipal recycled water systems using fluorescence spectroscopy: Implications for integrity monitoring

“…Several publications have focused on fouling in membrane bioreactors (MBR) for wastewater treatment [15,[24][25][26][27]. Fluorescence spectroscopy has also been used to monitor and model the performance of membrane bioreactors [28,29].…”

Understanding and Control of Biopolymer Fouling in Ultrafiltration of Different Water Types

“…SE biopolymers are the macromolecular fraction of effluent organic matter (EfOM). They are mostly solvable microbiological products (SMP) secreted by microorganisms during metabolism and/or related to extracellular polymeric substances (EPS) [6][7][8]. Using advanced characterization technologies, the presence of proteins and polysaccharides in this fraction are clearly identified [2].…”