title: Comparison of Nitrilotriacetic Acid and [S,S]-Ethylenediamine-N,N'-disuccinic Acid in UV-Fenton for the Treatment of Oil Sands Process-Affected Water at Natural pH.
abstract: The application of UV-Fenton processes with two chelating agents, nitrilotriacetic acid (NTA) and [S,S]-ethylenediamine-N,N'-disuccinic acid ([S,S]-EDDS), for the treatment of oil sands process-affected water (OSPW) at natural pH was investigated. The half-wave potentials of Fe(III/II)NTA and Fe(III/II)EDDS and the UV photolysis of the complexes in Milli-Q water and OSPW were compared. Under optimum conditions, UV-NTA-Fenton exhibited higher efficiency than UV-EDDS-Fenton in the removal of acid extractable organic fraction (66.8% for the former and 50.0% for the latter) and aromatics (93.5% for the former and 74.2% for the latter). Naphthenic acids (NAs) removals in the UV-NTA-Fenton process (98.4%, 86.0%, and 81.0% for classical NAs, NAs + O (oxidized NAs with one additional oxygen atom), and NAs + 2O (oxidized NAs with two additional oxygen atoms), respectively) under the experimental conditions were much higher than those in the UV-H2O2(88.9%, 48.7%, and 54.6%, correspondingly) and NTA-Fenton (69.6%, 35.3%, and 44.2%, correspondingly) processes. Both UV-NTA-Fenton and UV-EDDS-Fenton processes presented promoting effect on the acute toxicity of OSPW toward Vibrio fischeri. No significant change of the NTA toxicity occurred during the photolysis of Fe(III)NTA; however, the acute toxicity of EDDS increased as the photolysis of Fe(III)EDDS proceeded. NTA is a much better agent than EDDS for the application of UV-Fenton process in the treatment of OSPW.
authors: Department of Civil and Environmental Engineering, University of Alberta , Edmonton, Alberta Canada T6G 1H9.
authors: Ying
authors: Y
authors: Zhang
authors: Department of Civil and Environmental Engineering, University of Alberta , Edmonton, Alberta Canada T6G 1H9.
authors: Nikolaus
authors: N
authors: Klamerth
authors: Department of Civil and Environmental Engineering, University of Alberta , Edmonton, Alberta Canada T6G 1H9.
authors: Pamela
authors: P
authors: Chelme-Ayala
authors: Department of Civil and Environmental Engineering, University of Alberta , Edmonton, Alberta Canada T6G 1H9.
authors: Mohamed
authors: M
authors: Gamal El-Din
mesh_terms: D005029:Ethylenediamines / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009571:Nitrilotriacetic Acid; D061329:Oil and Gas Fields; D014867:Water
chemical_list: D005029:Ethylenediamines; D014867:Water; D006861:Hydrogen Peroxide; D009571:Nitrilotriacetic Acid