title: Evaluating Activated Carbon Adsorption of Dissolved Organic Matter and Micropollutants Using Fluorescence Spectroscopy.
abstract: Dissolved organic matter (DOM) negatively impacts granular activated carbon (GAC) adsorption of micropollutants and is a disinfection byproduct precursor. DOM from surface waters, wastewater effluent, and 1 kDa size fractions were adsorbed by GAC and characterized using fluorescence spectroscopy, UV-absorption, and size exclusion chromatography (SEC). Fluorescing DOM was preferentially adsorbed relative to UV-absorbing DOM. Humic-like fluorescence (peaks A and C) was selectively adsorbed relative to polyphenol-like fluorescence (peaks T and B) potentially due to size exclusion effects. In the surface waters and size fractions, peak C was preferentially removed relative to peak A, whereas the reverse was found in wastewater effluent, indicating that humic-like fluorescence is associated with different compounds depending on DOM source. Based on specific UV-absorption (SUVA), aromatic DOM was preferentially adsorbed. The fluorescence index (FI), if interpreted as an indicator of aromaticity, indicated the opposite but exhibited a strong relationship with average molecular weight, suggesting that FI might be a better indicator of DOM size than aromaticity. The influence of DOM intermolecular interactions on adsorption were minimal based on SEC analysis. Fluorescence parameters captured the impact of DOM size on the fouling of 2-methylisoborneol and warfarin adsorption and correlated with direct competition and pore blockage indicators.
authors.affiliation: Department of Civil, Environmental and Architectural Engineering, 428 UCB, University of Colorado, Boulder , Boulder, Colorado 80309, United States.
authors.forename: Kyle K
authors.identifier: 0000-0001-8497-5945
authors.initials: KK
authors.lastname: Shimabuku
authors.affiliation: Department of Civil, Environmental and Architectural Engineering, 428 UCB, University of Colorado, Boulder , Boulder, Colorado 80309, United States.|Technical Service Center, US Bureau of Reclamation , Denver Federal Center Building 67, Denver, Colorado 80225, United States.
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Kennedy
authors.affiliation: Department of Civil, Environmental and Architectural Engineering, 428 UCB, University of Colorado, Boulder , Boulder, Colorado 80309, United States.
authors.forename: Riley E
authors.identifier: 0000-0001-6293-3672
authors.initials: RE
authors.lastname: Mulhern
authors.affiliation: Department of Civil, Environmental and Architectural Engineering, 428 UCB, University of Colorado, Boulder , Boulder, Colorado 80309, United States.
authors.forename: R Scott
authors.initials: RS
authors.lastname: Summers
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D062065:Wastewater; D018508:Water Purification
chemical_list: D002606:Charcoal; D009930:Organic Chemicals; D062065:Wastewater