title: Temporal variations of membrane foulants in the process of using flat-sheet membrane for simultaneous thickening and digestion of waste activated sludge.
abstract: Membrane foulants were extracted at different operation time in simultaneous sludge thickening and digestion reactors using flat-sheet membranes. Temporal variations of foulants were analyzed by three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy, gel filtration chromatography (GFC), particle size distribution (PSD) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. Results showed that during the first 4days fouling was mainly assigned to internal membrane foulants (IMFs), and afterwards external membrane foulants (EMFs) increased dramatically. EEM analysis showed that both IMFs and EMFs changed during the operation. Cluster analysis demonstrated that the characteristics of IMFs were relatively similar; however, both quantity and properties of EMFs were changed. GFC analysis showed that EMFs contained more molecules with large molecular weight compared to IMFs. PSD analysis illuminated that particle size of EMFs gradually increased and was larger than that of IMFs. ATR-FTIR analysis indicated that the foulants on membranes consisted of polysaccharides and proteins.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Wu
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Zhu
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Wang
mesh_terms: D057219:Biofouling; D002850:Chromatography, Gel; D016000:Cluster Analysis; D008567:Membranes, Artificial; D010316:Particle Size; D010865:Pilot Projects; D012722:Sewage / Q000032:analysis*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D013997:Time Factors; D014835:Volatilization; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D012722:Sewage