title: Complexation-flocculation of organic contaminants by the application of oxyhumolite-based humic organic matter.
abstract: Control of hazardous organic micropollutants is a challenging water quality issue. Dissolved humic organic matter (DOM) isolated from oxyhumolite coal mined in Bohemia was investigated as a complexation agent to remove polycyclic aromatic hydrocarbons (PAHs) and functionalized phenols from water by a two-stage process involving complexation and flocculation. After the formation of humic-contaminant complexes, ferric salts were added resulting in the precipitation and flocculation of the DOM and the associated pollutants. Flocculation experiments with ferric ion coagulants indicated that precipitation of oxyhumolite DOM together with the complexed contaminants occurred at lower ferric ion concentrations than with the reference DOM in acidic environments (pH approximately 3.5). The complexation-flocculation removal rates for non-reactive PAHs characterized by small localization energies of pi-electrons correlated well with the complexation constants. On the other hand, the combined complexation-flocculation removal rates for activated PAHs including trans-stilbene, anthracene and 9-methyl anthracene, as well as functionalized polar phenols, were higher than predicted from the complexation coefficients. Methodological studies revealed for the first time that the ferric ion coagulant contributed to enhanced removal rates, most probably due to ferric ion-catalyzed pollutant degradation resulting in oxidized products.
authors.affiliation: Department of Environmental Technology, UFZ-Helmholtz Centre for Environmental Research Leipzig-Halle Ltd., Permoserstr. 15, 04318 Leipzig, Germany. juergen.poerschmann@ufz.de
authors.forename: Juergen
authors.initials: J
authors.lastname: Poerschmann
authors.forename: Ulf
authors.initials: U
authors.lastname: Trommler
authors.forename: Petra
authors.initials: P
authors.lastname: Nyplova
authors.forename: Peter
authors.initials: P
authors.lastname: Morgenstern
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Górecki
mesh_terms: D005427:Flocculation; D008401:Gas Chromatography-Mass Spectrometry; D006812:Humic Substances / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*
chemical_list: D006812:Humic Substances; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical