Polymeric compounds in activated sludge supernatant -- Characterisation and retention mechanisms at a full-scale municipal membrane bioreactor.
In this study, for the first time a full-scale membrane bioreactor (MBR) was investigated with focus on organic compounds in activated sludge over a period of approximately 2 years. Soluble extracellular polymeric substances (EPS) in the sludge supernatant and permeate as well as bound EPS extracted from fouled membranes were determined photospectrometrically and revealed a typical composition of three main components in the order metals>humic acids>carbohydrates>proteins. Results showed an important influence on membrane fouling by soluble humic substances and carbohydrates in complexes with metal cations. It was found that Fe(2+) and Fe(3+) play a decisive role in natural organic matter (NOM) complexation and subsequent membrane blockage. The determination of molar mass distribution in supernatant and permeate by size exclusion chromatography (SEC) revealed a significant retention of macromolecular compounds by the porous membranes in the range of 10-50%.
Lyko
Sven
S
Department of Chemical Engineering, RWTH Aachen University, Turmstr. 46, D-52056 Aachen, Germany. lyko@ivt.rwth-aachen.de
Al-Halbouni
Djamila
D
Wintgens
Thomas
T
Janot
Andreas
A
Hollender
Juliane
J
Dott
Wolfgang
W
Melin
Thomas
T
D019149:Bioreactors; D002413:Cations, Divalent; D002850:Chromatography, Gel; D005858:Germany; D008567:Membranes, Artificial; D008970:Molecular Weight; D011108:Polymers / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D012995:Solubility; D013997:Time Factors; D014462:Ultrafiltration
D002413:Cations, Divalent; D008567:Membranes, Artificial; D011108:Polymers; D012722:Sewage