eprintid: 1722 rev_number: 14 eprint_status: archive userid: 6 dir: disk0/00/00/17/22 datestamp: 2016-09-15 11:18:43 lastmod: 2017-02-08 12:21:37 status_changed: 2016-09-15 11:18:43 type: article metadata_visibility: show creators_name: Klamerth, Nikolaus creators_name: Moreira, Jesús creators_name: Li, Chao creators_name: Singh, Arvinder creators_name: McPhedran, Kerry N. creators_name: Chelme-Ayala, Pamela creators_name: Belosevic, Miodrag creators_name: Gamal El-Din, Mohamed corp_creators: Department of Civil and Environmental Engineering,Natural Resources Engineering Facility, University of Alberta,Canada corp_creators: Department of Civil and Environmental Engineering,Natural Resources Engineering Facility, University of Alberta,Canada corp_creators: Department of Civil and Environmental Engineering,Natural Resources Engineering Facility, University of Alberta,Canada corp_creators: Department of Civil and Environmental Engineering,Natural Resources Engineering Facility, University of Alberta,Canada, Department of Biological Sciences, University of Alberta, Canada corp_creators: Department of Civil and Environmental Engineering,Natural Resources Engineering Facility, University of Alberta,Canada corp_creators: Department of Civil and Environmental Engineering,Natural Resources Engineering Facility, University of Alberta,Canada corp_creators: Department of Biological Sciences, University of Alberta, Canada corp_creators: Department of Civil and Environmental Engineering,Natural Resources Engineering Facility, University of Alberta,Canada title: Effect of ozonation on the naphthenic acids' speciation and toxicity of pH-dependent organic extracts of oil sands process-affected water subjects: O subjects: RCA1 subjects: SHC subjects: SHU divisions: SHEER full_text_status: none abstract: The presence of naphthenic acids (NAs) and other organic constituents in oil sands process-affected water (OSPW) stored in tailings ponds, poses a serious environmental threat due to their potential toxicity to aquatic organisms and wild life. In this work, four fractions of OSPW, extracted by dichloromethane at different pHs, were ozonated to determine the ozone impact on NAs degradation. Extracts distributions showed that high carbon number NAs (14–22) were associated with higher pH fractions (pH > 7) and smaller carbon number NAs (7–13) with lower pH fractions (pH ≤ 7). Extracts showed similar hydrogen deficiency (Z-number) patterns centered on Z = 6. Analysis of the speciation of NAs and oxidized NAs in the four fractions showed that ozonation degraded most NAs (55% to 98%). Despite the high degradation levels, there was still significant toxicity of the fractions toward goldfish macrophages and measurable toxicity toward Vibrio fischeri. The toxicity of such a complex matrix as OSPW may be attributed to other organic compounds and degradation by-products not currently detected. Thus, there is a need to elucidate which compounds are responsible for the remaining OSPW toxicity and to determine if combined processes, such as ozonation followed by biological treatment, are able to completely detoxify OSPW. This work is taking the first steps into this direction, narrowing down the range of compounds which might be responsible for the toxicity. date: 2015-02 date_type: published publication: Science of The Total Environment volume: 506-50 publisher: Elsevier pagerange: 66-75 id_number: doi:10.1016/j.scitotenv.2014.10.103 issn: 0048-9697 official_url: http://doi.org/10.1016/j.scitotenv.2014.10.103 access_IS-EPOS: limited owner: Publisher citation: Klamerth, Nikolaus and Moreira, Jesús and Li, Chao and Singh, Arvinder and McPhedran, Kerry N. and Chelme-Ayala, Pamela and Belosevic, Miodrag and Gamal El-Din, Mohamed (2015) Effect of ozonation on the naphthenic acids' speciation and toxicity of pH-dependent organic extracts of oil sands process-affected water. Science of The Total Environment, 506-50. pp. 66-75. DOI: https://doi.org/10.1016/j.scitotenv.2014.10.103