Dynamic changes of dissolved organic matter in membrane bioreactors at different organic loading rates: Evidence from spectroscopic and chromatographic methods.
Excitation emission matrix-parallel factor analysis (EEM-PARAFAC) and size exclusion chromatography (SEC) were utilized to explore the dynamics in extracellular polymeric substances (EPS), soluble microbial products (SMP), and effluent for the membrane bioreactors at two different organic loading rates (OLRs). Combination of three different fluorescent components explained the compositional changes of dissolved organic matter. The lower OLR resulted in a higher production of tryptophan-like component (C1) in EPS, while the opposite trends were found for the other two components (humic-like C2 and tyrosine-like C3), signifying the role of C1 in the endogenous condition. Larger sized molecules were more greatly produced in EPS at the lower OLR. Meanwhile, all the size fractions of SMP were more abundant at the higher OLR particular for the early phase of the operation. Irrespective of the OLR, the higher degrees of the membrane retention were found for relatively large sized and protein-like molecules.
Department of Environment and Energy, Sejong University, Seoul 05006, South Korea.
Tahir
T
Maqbool
Department of Environment and Energy, Sejong University, Seoul 05006, South Korea.
Jinwoo
J
Cho
Department of Environment and Energy, Sejong University, Seoul 05006, South Korea. Electronic address: jinhur@sejong.ac.kr.
Jin
J
Hur
D019149:Bioreactors; D002850:Chromatography, Gel; D004396:Coloring Agents; D005163:Factor Analysis, Statistical; D013050:Spectrometry, Fluorescence
D004396:Coloring Agents
EEM-PARAFAC; Food to microorganism ratio; Membrane bioreactor; Organic loading rate; SEC-OCD