title: Characterization of natural organic matter treated by iron oxide nanoparticle incorporated ceramic membrane-ozonation process.
abstract: In this study, changes in the physical and structural properties of natural organic matter (NOM) were observed during hybrid ceramic membrane processes that combined ozonation with ultrafiltration ceramic membrane (CM) or with a reactive ceramic membrane (RM), namely, an iron oxide nanoparticles (IONs) incorporated-CM. NOM from feed water and NOM from permeate treated with hybrid ceramic membrane processes were analyzed by employing several NOM characterization techniques. Specific ultraviolet absorbance (SUVA), high-performance size exclusion chromatography (HPSEC) and fractionation analyses showed that the hybrid ceramic membrane process effectively removed and transformed relatively high contents of aromatic, high molecular weight and hydrophobic NOM fractions. Fourier transform infrared spectroscopy (FTIR) and 3-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy revealed that this process caused a significant decrease of the aromaticity of humic-like structures and an increase in electron withdrawing groups. The highest removal efficiency (46%) of hydroxyl radical probe compound (i.e., para-Chlorobenzoic acid (pCBA)) in RM-ozonation process compared with that in CM without ozonation process (8%) revealed the hydroxyl radical formation by the surface-catalyzed reaction between ozone and IONs on the surface of RM. In addition, experimental results on flux decline showed that fouling of RM-ozonation process (15%) was reduced compared with that of CM without ozonation process (30%). These results indicated that the RM-ozonation process enhanced the destruction of NOM and reduced the fouling by generating hydroxyl radicals from the catalytic ozonation in the RM-ozonation process.
authors.affiliation: Department of Chemical and Environmental Engineering, University of California-Riverside, Riverside, CA 92521, USA.
authors.forename: Hosik
authors.initials: H
authors.lastname: Park
authors.forename: Yohan
authors.initials: Y
authors.lastname: Kim
authors.forename: Byungryul
authors.initials: B
authors.lastname: An
authors.forename: Heechul
authors.initials: H
authors.lastname: Choi
mesh_terms: D002516:Ceramics / Q000737:chemistry*; D002850:Chromatography, Gel; D005290:Ferric Compounds / Q000737:chemistry*; D008567:Membranes, Artificial; D053758:Nanoparticles / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D005290:Ferric Compounds; D008567:Membranes, Artificial; C000499:ferric oxide; D010126:Ozone