Publications by authors named "Shirley Anne Smyth"

22 Publications

  • Page 1 of 1

Removal and formation of perfluoroalkyl substances in Canadian sludge treatment systems - A mass balance approach.

Sci Total Environ 2021 Feb 21;754:142431. Epub 2020 Sep 21.

Science and Technology Branch, Environment and Climate Change Canada, Burlington, ON L7S 1A1, Canada.

Poly- and per-fluoroalkyl substances (PFAS) are an emerging class of anthropogenic contaminants whose occurrence has raised concerns with the beneficial reuse of biosolids from wastewater treatment. This study evaluated the behavior of thirteen PFAS in nine Canadian sludge treatment systems including pelletization, alkaline stabilization, aerobic and anaerobic digestion processes. The composition of the overall PFAS-fluorine (ΣPFAS-F) loading in a system fed with only primary sludge was dominated by perfluorodecanoate (PFDA), whereas systems with blended primary and waste activated sludge feeds had a mix of short and long chain PFAS in raw sludges and treated biosolids. An increase in average ΣPFAS-F mass flow was observed through pelletization (19% formation) and alkaline stabilization (99% formation) processes indicating negative removal or contaminant formation. One of the two aerobic digestion systems and three of the five anaerobic digestion systems showed modest reductions (< 40% removal) in ΣPFAS-F loading. Long chain PFAS such as perfluorodecanoate (PFDA) and perfluorooctane sulfonate (PFOS) exhibited a wide variation in behavior ranging from substantial formation (> 75% formation) to modest removal (42% removal) in the surveyed systems while short chain perfluoropentanoate (PFPeA) mass flows increased through the three systems where they occurred. Overall, the contaminant mass balances revealed that there were significant changes in mass flows of the target PFAS through all kinds of sludge treatment systems. The results of this study on PFAS fate through sludge processing can inform future global PFAS risk management activities as well as sludge treatment considerations.
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http://dx.doi.org/10.1016/j.scitotenv.2020.142431DOI Listing
February 2021

Diphenylamine Antioxidants in wastewater influent, effluent, biosolids and landfill leachate: Contribution to environmental releases.

Water Res 2021 Feb 3;189:116602. Epub 2020 Nov 3.

International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China; International Joint Research Center for Arctic Environment and Ecosystem (IJRC-AEE), Polar Academy, Harbin Institute of Technology, Harbin 150090, China; IJRC-PTS-NA, Toronto, M2N 6X9, Canada.

Diphenylamine antioxidants (DPAs) are widely used industrial chemicals. Wastewater effluents and biosolids are important pathways for DPAs to enter the environment. Information on the fate of DPAs in wastewater treatment plants (WWTPs) and their environmental releases is limited. In this study, we characterized the occurrence, removal efficiencies, distribution, mass balance, and environmental releases of 17 DPAs in ten Canadian WWTPs and four landfill sites from 2013 to 2015. These WWTPs are different in sizes, and treatment technologies. Median concentrations of ΣDPAs were 78 ng/L in influent, 6.9 ng/L in effluent, 326 ng/L in leachate, and 445 ng/g in biosolids (dry weight), respectively. Diphenylamine (DPA) and ditertoctyl-diphenylamine (DTO-DPA) were the predominant congeners of DPAs in all the matrices. Residues of DPAs were not completely removed during wastewater treatment processes: most DPAs were detected in at least one sample of WWTP effluent with the highest concentration of 117 ng/L (DPA). Overall, high removal efficiencies (median > 90%) of most of the DPAs were observed in the secondary and advanced treatment, as well as in the facultative and aerated lagoons. In contrast, primary treatment exhibited a lower removal efficiency of the DPAs. Mass balance analysis shows that sorption to biosolids is the major removal pathway of DPAs in WWTPs. The results also highlight that environmental releases of DPAs via biosolid applications (70 mg/d/1000 people) can be over several times higher than that via wastewater effluent (2.5-36 mg/d/1000 people).
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http://dx.doi.org/10.1016/j.watres.2020.116602DOI Listing
February 2021

Bisphenol A in the Canadian environment: A multimedia analysis.

Sci Total Environ 2021 Feb 24;755(Pt 2):142472. Epub 2020 Sep 24.

Environmental Protection Branch, Environment and Climate Change Canada, Gatineau, Quebec K1A 0H3, Canada.

Bisphenol A (BPA) is an industrial chemical that has been identified by some jurisdictions as an environmental concern. In 2010, Canada concluded that this substance posed a risk to the environment and human health, and implemented actions to reduce its concentrations in the environment. To support these activities, a multimedia analysis of BPA in the Canadian environment was conducted to evaluate spatial and temporal trends, and to infer mechanisms influencing the patterns. BPA was consistently detected in wastewater and biosolids across Canadian wastewater treatment plants (WWTPs) and in landfill leachate. In addition, BPA concentrations were significantly higher in surface water downstream compared to upstream of WWTPs in three of five urban areas evaluated. However, application of biosolids to Canadian agricultural fields did not contribute to elevated BPA concentrations in soil, earthworms, and European Starling (Sturnus vulgaris) plasma one and two years post-treatment. Spatial trends of BPA concentrations in surface water and sediment are influenced by human activity, with higher concentrations typically found downstream of industrial sources and WWTPs in urban areas. BPA was detected in bird plasma at locations impacted by WWTPs and landfills. However, spatial trends in birds were less clear and may have been confounded by metabolic biotransformation. In terms of temporal trends, BPA concentrations in surface water decreased significantly at 10 of 16 monitoring sites evaluated between 2008 and 2018. In contrast, recent temporal trends of BPA in six sediment cores were variable, which may be a result of biotransformation of the flame retardant tetrabromobisphenol A to BPA. Overall, our study provides evidence that Government of Canada actions have been generally successful in reducing BPA concentrations in the Canadian environment. Our results indicate that long-term monitoring programs using surface water are more effective than other media for tracking and understanding future environmental trends of BPA.
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http://dx.doi.org/10.1016/j.scitotenv.2020.142472DOI Listing
February 2021

Variable persistence of artificial sweeteners during wastewater treatment: Implications for future use as tracers.

Water Res 2020 Oct 1;184:116124. Epub 2020 Jul 1.

Science and Risk Assessment Directorate, Environment and Climate Change Canada, 867 Lakeshore Road, Burlington, Ontario, L7S 1A1, Canada.

For more than a decade the artificial sweeteners acesulfame (ACE) and sucralose (SUC) have been applied as tracers of the input of wastewater to environmental waters. Recently concerns have been raised that degradation of ACE during treatment may hinder or restrict its use as a wastewater tracer. In this study the value of ACE and SUC as tracers was reassessed based on samples of wastewater at 12 municipal wastewater treatment (MWWT) plants and from 7 septic systems and associated septic plumes in groundwater. The results indicated stability of SUC during MWWT at most plants, and variable removal of both sweeteners during some MWWT and in the septic wastewater systems. However, the residual concentrations of ACE and SUC in municipal effluent and in septic plumes indicate that both sweeteners remain valuable wastewater tracers. The mass ratio SUC/ACE was found to be a useful parameter for examining the relative persistence of these sweeteners.
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http://dx.doi.org/10.1016/j.watres.2020.116124DOI Listing
October 2020

Wastewater Treatment Lagoons: Local Pathways of Perfluoroalkyl Acids and Brominated Flame Retardants to the Arctic Environment.

Environ Sci Technol 2020 05 8;54(10):6053-6062. Epub 2020 May 8.

Science and Technology Branch, Environment and Climate Change Canada, 867 Lakeshore Road, Burlington, Ontario L7S 1A1, Canada.

Concentrations of perfluoroalkyl acids (PFAAs), polybrominated diphenyl ethers (PBDEs), and "novel" brominated flame retardants (NBFRs) were determined in lagoons processing wastewater from two high-Arctic and two sub-Arctic of Canada communities to assess the importance of local anthropogenic sources. ∑PFAAs in influent and effluent of the Arctic lagoons were within the lower end of the range of concentrations previously observed in Canadian temperate wastewater treatment plants (WWTPs). In comparison, influent and effluent concentrations of ∑PBDEs and NBFRs were significantly greater ( < 0.05) in high-Arctic lagoons compared to sub-Arctic and temperate plants. The surprisingly elevated concentrations of PBDEs and NBFRs in high-Arctic lagoons were probably related to high organic matter found in Arctic wastewater due to lower consumption of potable water leading to less dilution compared to temperate regions. Although PFAAs also sorb to solids, the wastewater samples were filtered prior to analysis of PFAAs (but not PBDEs and NBFRs), which likely reduced the impacts of solids on the results for PFAAs. Based on an extrapolation of per capita mass effluent loadings of the four Arctic lagoons, mass loadings to the Arctic of Canada via WWTP effluent were estimated as 1405 g/year and 549 g/year for ∑PFAAs and ∑PBDEs, respectively.
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http://dx.doi.org/10.1021/acs.est.9b06902DOI Listing
May 2020

Detections of alkyl-phenoxy-benzenesulfonates in municipal wastewater.

Chemosphere 2020 Jul 29;251:126386. Epub 2020 Feb 29.

Science and Risk Assessment Directorate, Environment and Climate Change Canada, 867 Lakeshore Road, Burlington, Ontario, L7S 1A1, Canada.

This study presents the first reported detections and concentrations of alkyl phenoxy-benzenesulfonate surfactants (APBS) in municipal wastewater. A semi quantitative direct injection LC/MS/MS method was developed. Samples of raw influent and final effluent were obtained from fourteen municipal wastewater treatment plants (WWTPs) at various locations in Canada and were analyzed for APBS, including five homologues of monoalkyldiphenylether disulfonates (MADS) and one monoalkyldiphenylether sulfonate (MAMS) homologue. APBS were detected in all 42 of the wastewater raw influent samples and in 37 of the 42 wastewater final effluent samples; the other 5 final effluent samples had trace levels below the minimum detection limit. In the samples of raw influent from the fourteen municipal treatment plants, the dissolved concentrations of APBS (total) ranged from 0.9 to 13.6 μg/L. In samples of final effluent from the same plants the total APBS ranged from below detection to 4 μg/L. The APBS were more resistant to loss during wastewater treatment compared to previous studies of linear alkylbenzene sulfonates in wastewaters. The most effective wastewater treatments for removal of APBS were those that involved either secondary treatment with aeration or advanced treatment including biological nutrient removal. Available information on ecotoxicity is lacking for evaluating the impacts of APBS surfactants when released to the environment.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126386DOI Listing
July 2020

Side-chain fluorinated polymer surfactants in biosolids from wastewater treatment plants.

J Hazard Mater 2020 04 10;388:122044. Epub 2020 Jan 10.

Emerging Priorities Division, Science and Risk Assessment Directorate, Environment and Climate Change Canada, 867 Lakeshore Road, Burlington, ON, L7S 1A1, Canada.

High concentrations of the main components in Scotchgard™ fabric protector products (pre-2002 and post-2002; side-chain fluorinated polymer surfactants, S1 and S2, respectively) were detected in biosolids samples from twenty pan-Canadian wastewater treatment plants (WWTPs). Based on mass spectrometric analysis, S1 and S2 can be named as side-chain perfluorooctane sulfonamide-urethane polymer and side-chain perfluorobutane sulfonamide-urethane polymer, respectively. S1 (with CF side-chain) concentrations ranged from 1.08-105 ng/g d.w. and S2 (with CF side-chain) concentrations ranged from 37.5-2051 ng/g d.w., which were much higher than that of other commonly monitored perfluoroalkyl substances (PFAS). S1 and S2 concentrations were significantly correlated (p < 0.001; r = 0.6142) indicating similar source origins. A negative linear correlation was observed (p < 0.05) between concentrations of S1 (or S2) with the volume of WWTP treated wastewater per day per person (m/person/day). The total concentration of 22 other PFAS ranged from 4.93 to 92.6 ng/g d.w., and approximately thirty times lower than S1 and S2 concentrations. The calculated elemental fluorine concentrations of ƩF were generally much higher than the sum of the other PFAS. PFAS concentrations in biosolids are likely underestimated without consideration of S1 and S2.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122044DOI Listing
April 2020

Occurrence and removal of triclosan in Canadian wastewater systems.

Environ Sci Pollut Res Int 2019 Nov 5;26(31):31873-31886. Epub 2019 Sep 5.

Environment and Climate Change Canada, Science and Technology Branch, 867 Lakeshore Road, Burlington, ON, L7S 1A1, Canada.

Triclosan (TCS) is an antimicrobial agent used in many personal care and cleaning products. It has been detected in most environmental compartments and the main entry pathway is wastewater effluents and biosolids. TCS was analyzed in 300 samples of raw influent, final effluent, and biosolids from 13 wastewater treatment plants (WWTPs) across Canada representing five types of typical wastewater treatment systems. TCS was almost always detected in influent (median 1480 ng/L), effluent (median 107 ng/L), and biosolids (median 8000 ng/g dry weight) samples. Removals of TCS from lagoons as well as secondary and advanced treatment facilities were significantly higher than primary treatment facilities (p < 0.001). TCS removal was strongly correlated with organic nitrogen removal. TCS removals at most lagoons and plants that use biological treatment were higher during summer compared with winter. However, no seasonal or temperature effects were observed at the two primary facilities, likely due to the absence of biological activity. Aerobically digested solids contained the lowest levels (median 555 ng/g) while anaerobically digested primary solids contained the highest levels of TCS (median 22,700 ng/g). The results of this large comprehensive study demonstrate that TCS is consistently present in wastewater and biosolids at relatively high concentrations and that removal from wastewater and levels in biosolids are strongly influenced by the wastewater and solids treatment types.
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http://dx.doi.org/10.1007/s11356-019-06338-wDOI Listing
November 2019

Distribution and fate of synthetic phenolic antioxidants in various wastewater treatment processes in Canada.

Chemosphere 2019 Mar 11;219:826-835. Epub 2018 Dec 11.

Science & Technology Branch, Environment and Climate Change Canada, 867 Lakeshore Road, Burlington, Ontario, L7S 1A1, Canada. Electronic address:

Synthetic phenolic antioxidants (SPAs) are of emerging concern due to their potential environmental risks. However, the environmental occurrence and fate of SPAs are poorly understood. In this study, 13 SPAs were analyzed in 70 liquid and 21 solid samples from 12 wastewater treatment plants (WWTPs) in 2016 to investigate the distribution and composition of SPAs in different wastewater treatment processes in Canada. Wastewater samples were liquid-liquid extracted and biosolids were treated using ultrasonic assisted solvent extraction. SPAs were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The concentrations of total SPAs were in the ranges of 71-3193 ng L in influent, less than method quantification limits (MQLs)-520 ng L in effluent, and 479-4794 ng g in biosolids (dry weight (dw)). SPAs were effectively removed (median >75%) from the liquid stream in most WWTPs. In one aerated lagoon and two primary treatment sites, low removal efficiency (median -26%-43%) was observed for 4-tert-octylphenol (4-tOP). These results indicate that wastewater effluent is a vector for SPAs, including the endocrine disruptor 4-tOP, to aquatic environments. The mass balance approximation found major removal mechanisms are sludge sorption/separation and degradation. A preliminary risk assessment suggested that most SPAs in WWTP effluent were unlikely to pose ecotoxicological risks to aquatic organisms in the receiving waters. Future research should evaluate the environmental risks of SPAs associated with land application of biosolids and investigate the occurrence and fate of the degradation products of these contaminants.
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http://dx.doi.org/10.1016/j.chemosphere.2018.12.068DOI Listing
March 2019

Variability of release rate of flame retardants in wastewater treatment plants.

Environ Sci Pollut Res Int 2018 Dec 15;25(34):34740-34752. Epub 2018 Oct 15.

Science and Risk Assessment Directorate, Science and Technology Branch, Environment and Climate Change Canada, 351 Saint Joseph Boulevard, Gatineau, Quebec, K1A 0H3, Canada.

Information on variability is important in the assessment of the releases and potential risks of brominated flame retardants (BRFs) in the environment, but related data are limited. In this study, two release-characterizing parameters, release fraction to final effluent and influent-biosolids transfer coefficient, were used to quantify releases of five BFRs from eight secondary wastewater treatment plants (WWTPs). The five BFRs are recalcitrant, hydrophobic, and low in volatility. The two parameters for these BFRs were found to vary from day to day and season to season within individual WWTPs as well as from one WWTP to another. These temporal and spatial variations were, however, comparable to each other and both within a factor of 3 above or below the parameter averages. Averages for release fraction were in the range of 0.02-0.29 and those for influent-biosolids transfer coefficient in the range of 3-26 L/g, depending upon a given BFR at a given WWTP. These ranges and the observed factor-3 variability are not only useful for estimating releases of the five BFRs, but more importantly provide read-across data for the assessment of substances with similar physical-chemical properties.
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http://dx.doi.org/10.1007/s11356-018-3403-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6245005PMC
December 2018

Occurrence and fate of substituted diphenylamine antioxidants and benzotriazole UV stabilizers in various Canadian wastewater treatment processes.

Water Res 2017 11 23;124:158-166. Epub 2017 Jul 23.

Science & Technology Branch, Environment and Climate Change Canada, 867 Lakeshore Road, Burlington, Ontario, L7S 1A1, Canada. Electronic address:

Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are additives used in industrial and consumer products to prevent degradation or color change of materials, but their environmental fate and disposition are not well characterized. In this study, SDPAs and BZT-UVs were analyzed in 68 liquid and 39 solid samples collected from 9 wastewater treatment plants (WWTPs) in Canada to investigate the occurrence and fate of these contaminants. The median concentrations of ΣSDPAs and ΣBZT-UVs was 483 and 76.2 ng L in influent, 28.4 and 4.84 ng L in effluent, and 2750 and 457 ng g in biosolids (dry weight), respectively. Dinonyl-diphenylamine (C9C9) was the predominant congener of SDPAs in all matrices (>40%). For target BZT-UVs, the major components were 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (UV234) and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV328). SDPAs and BZT-UVs were effectively removed (>90%) from the liquid stream in most WWTPs mainly through sludge sorption and separation, but biotransformation, UV treatment and filtration may also contribute to removal of some contaminants in advanced treatment plants. In contrast, the removal efficiency of target contaminants using chemically assisted primary treatment was low, likely due to the short hydraulic retention time of this site. Our results suggest that wastewater effluent is a vector of SDPAs and BZT-UVs to the aquatic environment. The results also highlight the high concentrations of SDPAs and BZT-UVs associated with the solid stream in WWTPs, which could affect the beneficial use of biosolids (e.g., compost or land applications).
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http://dx.doi.org/10.1016/j.watres.2017.07.055DOI Listing
November 2017

Determination of substituted diphenylamines in environmental samples.

Anal Bioanal Chem 2016 Nov 23;408(28):7945-7954. Epub 2016 Sep 23.

Water Science and Technology Directorate, Environment and Climate Change Canada, 867 Lakeshore Road, Burlington, ON, L7S1A1, Canada.

Owing to their stability at high temperature, low biodegradation, low water solubility, and low vapor pressure, substituted diphenylamines are used as antioxidants in rubber, foamed polymers, and as high-temperature functional fluids (e.g., lubricants, gear oils, and hydraulic fluids). There are few existing environmental measurements of these substances in any environmental medium. In this study, a method was developed for the determination of 10 substituted diphenylamines in wastewater, biosolids, and sediments using gas chromatography-tandem mass spectrometry (GC-MS/MS). The substituted diphenylamines that were measured were two styrenated diphenylamines isomers, three di-styrenated diphenylamine isomers, tert-butyl-diphenylamine, tert-octyl-diphenylamine, di-tert-butyl-diphenylamine, tert-butyl/tert-octyl-diphenylamine, and di-tert-octyl-diphenylamine. The instrument limits of detection (LODs) and limits of quantitation (LOQs) were 0.02-0.1 and 0.06-0.3 ng mL, respectively. Target compounds were spiked into sediment, effluent water, influent water, and biosolids at the 100- and 1000-ng levels (N = 6). Analyte recoveries ranged from 71.5 to 117 % with relative standard deviations (RSDs) of 2.12-12.4 %. The method was applied to the analysis of influent, effluent, and biosolid samples; the sum of substituted diphenylamines were 48.1-713, 1.04-28.5 ngL, and 85.3-1184 nggdw (median: 71.0, 7.30 ngL, and 402 nggdw), respectively. Nine sediment samples collected in Ontario, Canada contained concentrations of the sum of substituted diphenylamines ranging from 1.55 to 897 nggdw.
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http://dx.doi.org/10.1007/s00216-016-9881-5DOI Listing
November 2016

Emission of poly and perfluoroalkyl substances, UV-filters and siloxanes to air from wastewater treatment plants.

Environ Pollut 2016 Nov 29;218:595-604. Epub 2016 Jul 29.

Air Quality Processes Research Section, Environment and Climate Change Canada, 4905 Dufferin St., Toronto, ON M3H 5T4, Canada.

The potential of wastewater treatment plants (WWTPs) to act as sources of poly and perfluoroalkyl substances (PFASs), volatile methyl siloxanes (VMSs) and organic UV-filters to the atmosphere was investigated. Target compounds included: PFASs (fluorotelomer alcohols (FTOHs), perfluorooctane sulfonamides/sulfonamidoethanols (FOSAs/FOSEs), perfluroalkyl sulfonic acids (PFSAs) and perfluroalkyl carboxylic acids (PFCAs)), cyclic VMSs (D3 to D6), linear VMSs (L3 to L5) and eight UV-filters. Emissions to air were assessed at eight WWTPs using paired sorbent-impregnated polyurethane foam passive air samplers, deployed during summer 2013 and winter 2014. Samplers were deployed on-site above the active tank and off-site as a reference. Several types of WWTPs were investigated: secondary activated sludge in urban areas (UR-AS), secondary extended aeration in towns (TW-EA) and facultative lagoons in rural areas (RU-LG). The concentrations of target compounds in air were ∼1.7-35 times higher on-site compared to the corresponding off-site location. Highest concentrations in air were observed at UR-AS sites while the lowest were at RU-LG. Higher air concentrations (∼2-9 times) were observed on-site during summer compared to winter, possibly reflecting enhanced volatilization due to higher wastewater temperatures or differences in influent wastewater concentrations. A significant positive correlation was obtained between concentrations in air and WWTP characteristics (influent flow rate and population in the catchment of the WWTP); whereas a weak negative correlation was obtained with hydraulic retention time. Emissions to air were estimated using a simplified dispersion model. Highest emissions to air were seen at the UR-AS locations. Emissions to air (g/year/tank) were highest for VMSs (5000-112,000) followed by UV-filters (16-2000) then ΣPFASs (10-110).
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http://dx.doi.org/10.1016/j.envpol.2016.07.043DOI Listing
November 2016

Evidence for Anaerobic Dechlorination of Dechlorane Plus in Sewage Sludge.

Environ Sci Technol 2015 Dec 20;49(23):13862-7. Epub 2015 Nov 20.

Department of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.

The environmental occurrence of dechlorination moieties from the high production volume flame retardant, Dechlorane Plus (DP), has largely been documented; however, the sources have yet to be well understood. In addition, few laboratory-based studies exist which identify the cause for the occurrence of these chemicals in the environment or humans. Anaerobic dechlorination of the two DP isomers was investigated using a laboratory-simulated wastewater treatment plant (WWTP) environment where anaerobic digestion is used as part of the treatment regime. Known amounts of each isomer were added separately to sewage sludge which provided the electron-donating substrate and at prescribed time points in the incubation, a portion of the media was removed and analyzed for DP and any dechlorination metabolites. After 7 days, monohydrodechlorinated products were observed for both the syn- and anti-DP which were continued throughout the duration of our study (49 days) in an increasing manner giving a calculated formation rate of 0.48 ± 0.09 and 0.79 ± 0.12 pmols/day for syn- and anti-DP, respectively. Furthermore, we observed a second monohydrodechlorinated product only in the anti-DP isomer incubation medium. This strongly suggests that anti-DP is more susceptible to anaerobic degradation than the syn isomer. We also provide compelling evidence to the location of chlorine loss in the dechlorination DP analogues. Finally, the dechlorination DP moieties formed in our study matched the retention times and identification of those observed in surficial sediment located downstream of the WWTP.
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http://dx.doi.org/10.1021/acs.est.5b03550DOI Listing
December 2015

Occurrence and Fate of Trace Contaminants during Aerobic and Anaerobic Sludge Digestion and Dewatering.

J Environ Qual 2015 Jul;44(4):1193-200

Digestion of municipal wastewater biosolids is a necessary prerequisite to their beneficial use in land application, in order to protect public health and the receiving environment. In this study, 13 pharmaceuticals and personal care products (PPCPs), 11 musks, and 17 polybrominated diphenyl ethers were analyzed in 84 samples including primary sludge, waste activated sludge, digested biosolids, dewatered biosolids, and dewatering centrate or filtrate collected from five wastewater treatment plants with aerobic or anaerobic digestion. Aerobic digestion processes were sampled during both warm and cold temperatures to analyze seasonal differences. Among the studied compounds, triclosan, triclocarban, galaxolide, and BDE-209 were the substances most frequently detected under different treatment processes at levels up to 30,000 ng/g dry weight. Comparing aerobic and anaerobic digestion, it was observed that the levels of certain PPCPs and musks were significantly higher in anaerobically digested biosolids, relative to the residues from aerobic digestion. Therefore, aerobic digestion has the potential advantage of reducing levels of PPCPs and musks. On the other hand, anaerobic digestion has the advantage of recovering energy from the biosolids in the form of combustible gases while retaining the nutrient and soil conditioning value of this resource.
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http://dx.doi.org/10.2134/jeq2015.01.0010DOI Listing
July 2015

Fate of anthropogenic cyclic volatile methylsiloxanes in a wastewater treatment plant.

Water Res 2015 Apr 16;72:209-17. Epub 2014 Oct 16.

Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, Ontario L7R 4A6, Canada. Electronic address:

The fate of cyclic volatile methylsiloxanes (cVMS) - octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) - was evaluated in a typical secondary activated sludge wastewater treatment plant (WWTP). Water samples (influent, primary effluent, and final effluent) and sludge (primary sludge and waste activated sludge) samples were collected at overnight low, morning high, afternoon low, and evening high flows. Concentrations of cVMS in influents fluctuated with the influent flows, ranging from 0.166 to 1.13 μg L(-1), 3.47-19.3 μg L(-1), and 0.446-3.87 μg L(-1) for D4, D5, and D6, respectively. Mass balance analysis of cVMS showed the average mass of D4, D5, and D6 entering and exiting the plant in influent and effluent, respectively, were 109 g d(-1), 2050 g d(-1), 280 g d(-1), and 1.41 g d(-1), 27.0 g d(-1), 1.90 g d(-1). The total removal efficiency of cVMS was >96%. To elucidate their detailed removal mechanisms, Mackay's fugacity-based treatment plant model was used to simulate the fate of cVMS through the WWTP. Due to the unusual combination of high hydrophobicity and volatility of cVMS, volatilization in the aeration tank and adsorption to sludge were the two main pathways of cVMS removal from water in this WWTP based on the experimental and modeled results. The morning and evening high influent mass flows contributed almost equally at approximately 40% of the total daily cVMS mass, with D5 accounting for the majority of this daily loading.
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http://dx.doi.org/10.1016/j.watres.2014.10.007DOI Listing
April 2015

In vitro immunotoxicity of untreated and treated urban wastewaters using various treatment processes to rainbow trout leucocytes.

J Environ Sci (China) 2013 Jul;25(7):1400-7

Emerging Methods, Aquatic Contaminants Research Division, Water Science and Technology, Environment Canada, 105 McGill Street, Montréal, Québec, Canada.

Municipal effluents are known to impede the immune system of aquatic organisms. The purpose of this study was to examine the immunotoxicity of urban wastewaters before and after 6 treatment processes from 12 cities toward trout leucocytes. Freshly prepared trout leucocytes were exposed to increasing concentrations of solid phase (C18) extracts of wastewaters for 24 hr at 150C. Immunocompetence was determined by following changes in leucocyte viability and the proportion of cells able to ingest at least one (immunoactivity) and at least three (immunoefficiency) fluorescent beads. The influents were treated by six different treatment strategies consisting of facultative aerated lagoons, activated sludge, biological aerated filter, biological nutrient removal, chemically-assisted physical treatment and trickling filter/solid contact. Water quality parameters of the wastewaters revealed that the plants effectively removed total suspended solids and reduced the chemical oxygen demand. The results revealed that the effluents' immunotoxic properties were generally more influenced by the properties of the untreated wastewaters than by the treatment processes. About half of the incoming influents decreased leucocyte viability while 4 treatment plants were able to reduce toxicity. The influents readily increased phagocytosis activity for 8/12 influents while it was decreased in 4/12 influents. This increase was abolished for 4/12 of the effluents using treatments involving biological and oxidative processes. In conclusion, municipal effluents have the potential to alter the immune system in fish and more research will be needed to improve the treatments of wastewaters to better protect the quality of the aquatic environment.
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http://dx.doi.org/10.1016/s1001-0742(12)60202-2DOI Listing
July 2013

Perfluoroalkyl acids in the Canadian environment: multi-media assessment of current status and trends.

Environ Int 2013 Sep 3;59:183-200. Epub 2013 Jul 3.

Conestoga-Rovers & Associates, 651 Colby Drive, Waterloo, ON, N2V 1C2, Canada.

In Canada, perfluoroalkyl acids (PFAAs) have been the focus of several monitoring programs and research and surveillance studies. Here, we integrate recent data and perform a multi-media assessment to examine the current status and ongoing trends of PFAAs in Canada. Concentrations of perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and other long-chain perfluorocarboxylates (PFCAs) in air, water, sediment, fish, and birds across Canada are generally related to urbanization, with elevated concentrations observed around cities, especially in southern Ontario. PFOS levels in water, fish tissue, and bird eggs were below their respective Draft Federal Environmental Quality Guidelines, suggesting there is low potential for adverse effects to the environment/organisms examined. However, PFOS in fish and bird eggs tended to exceed guidelines for the protection of mammalian and avian consumers, suggesting a potential risk to their wildlife predators, although wildlife population health assessments are needed to determine whether negative impacts are actually occurring. Long-term temporal trends of PFOS in suspended sediment, sediment cores, Lake Trout (Salvelinus namaycush), and Herring Gull (Larus argentatus) eggs collected from Lake Ontario increased consistently from the start of data collection until the 1990s. However, after this time, the trends varied by media, with concentrations stabilizing in Lake Trout and Herring Gull eggs, and decreasing and increasing in suspended sediment and the sediment cores, respectively. For PFCAs, concentrations in suspended sediment, sediment cores, and Herring Gulls generally increased from the start of data collection until present and concentrations in Lake Trout increased until the late 1990s and subsequently stabilized. A multimedia comparison of PFAA profiles provided evidence that unexpected patterns in biota of some of the lakes were due to unique source patterns rather than internal lake processes. High concentrations of PFAAs in the leachate and air of landfill sites, in the wastewater influent/effluent, biosolids, and air at wastewater treatment plants, and in indoor air and dust highlight the waste sector and current-use products (used primarily indoors) as ongoing sources of PFAAs to the Canadian environment. The results of this study demonstrate the utility of integrating data from different media. Simultaneous evaluation of spatial and temporal trends in multiple media allows inferences that would be impossible with data on only one medium. As such, more co-ordination among monitoring sites for different media is suggested for future sampling, especially at the northern sites. We emphasize the importance of continued monitoring of multiple-media for determining future responses of environmental PFAA concentrations to voluntary and regulatory actions.
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http://dx.doi.org/10.1016/j.envint.2013.05.008DOI Listing
September 2013

Concentrations of cyclic volatile methylsiloxanes in biosolid amended soil, influent, effluent, receiving water, and sediment of wastewater treatment plants in Canada.

Chemosphere 2013 Oct 22;93(5):766-73. Epub 2012 Nov 22.

Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, ON, Canada L7R 4A6.

A comprehensive surveillance program was conducted to determine the occurrence of three cyclic volatile methylsiloxanes (cVMS) octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in environmental compartments impacted by wastewater effluent discharges. Eleven wastewater treatment plants (WWTPs), representative of those found in Southern Ontario and Southern Quebec, Canada, were investigated to determine levels of cVMS in their influents and effluents. In addition, receiving water and sediment impacted by WWTP effluents, and biosolid-amended soil from agricultural fields were also analyzed for a preliminary evaluation of the environmental exposure of cVMS in media impacted by wastewater effluent and solids. A newly-developed large volume injection (septumless head adapter and cooled injection system) gas chromatography - mass spectrometry method was used to avoid contamination originating from instrumental analysis. Concentrations of D4, D5, and D6 in influents to the 11 WWTPs were in the range 0.282-6.69μgL(-1), 7.75-135μgL(-1), and 1.53-26.9μgL(-1), respectively. In general, wastewater treatment showed cVMS removal rates of greater than 92%, regardless of treatment type. The D4, D5, and D6 concentration ranges in effluent were <0.009-0.045μgL(-1), <0.027-1.56μgL(-1), and <0.022-0.093μgL(-1), respectively. The concentrations in receiving water influenced by effluent, were lower compared to those in effluent in most cases, with the ranges <0.009-0.023μgL(-1), <0.027-1.48μgL(-1), and <0.022-0.151μgL(-1) for D4, D5, and D6, respectively. Sediment concentrations ranged from <0.003-0.049μgg(-1)dw, 0.011-5.84μgg(-1)dw, and 0.004-0.371μgg(-1)dw for D4, D5, and D6, respectively. The concentrations in biosolid-amended soil, having values of <0.008-0.017μgg(-1)dw, <0.007-0.221μgg(-1)dw, and <0.009-0.711μgg(-1)dw for D4, D5, and D6, respectively, were lower than those in sediment impacted by wastewater effluent in most cases. In comparison with the no-observed-effected concentrations (NOEC) and IC50 (concentration that causes 50% inhibition of the response) values, the potential risks to aquatic, sediment-dwelling, and terrestrial organisms from these reported concentrations are low.
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http://dx.doi.org/10.1016/j.chemosphere.2012.10.047DOI Listing
October 2013

Sample storage and extraction efficiencies in determination of polycyclic and nitro musks in sewage sludge.

Chemosphere 2007 Feb 6;67(2):267-75. Epub 2006 Dec 6.

Environment Canada, Water Science and Technology Directorate, 867 Lakeshore Road, P.O. Box 5050, Burlington, Ont., Canada L7R 4A6.

Analytical technology is continuously improving, developing better methods for isolating and concentrating trace compounds in environmental samples. Polycyclic and nitro musks (PNMs) are one group of emerging trace compounds detected in municipal wastewater. Differences in sample storage, preparation, and extraction methods for their measurement have led to variability in results. We analyzed 11 PNMs by GC/MS and compared the results of different storage times and extraction methods (supercritical fluid (SFE) or microwave-assisted (MAE)) for 202 samples of primary sludge, waste activated sludge (WAS), raw sludge, and aerobically/anaerobically digested biosolids collected from Canadian municipal wastewater treatment plants. Sixty-three air-dried samples were extracted by SFE, and 139 air-dried, centrifuged, or filtered samples were extracted by MAE. The mean surrogate recoveries were 89% (standard deviation (SD)=11%) for d(10)-anthracene by SFE and 88% (SD=14%) for d(10)-phenanthrene by MAE. Storage study results showed that PNM concentrations changed by a mean of 7% and 9% for primary sludge and WAS respectively after four weeks and decreased up to 25% after 13.5 months of storage in amber glass containers at -18 degrees C. Air-drying of sludge at room temperature caused losses of about 50% of PNM concentrations compared to centrifugation. The proportions of PNMs present in the liquid phase of sludge samples were less than 5% compared to proportions in the sludge solids. The most complete liquid-solid separation was achieved by filtration of frozen/thawed sludge samples, producing a liquid phase that contained less than 1% of the total musk content of the sample.
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http://dx.doi.org/10.1016/j.chemosphere.2006.10.031DOI Listing
February 2007

Occurrence and reductions of pharmaceuticals and personal care products and estrogens by municipal wastewater treatment plants in Ontario, Canada.

Sci Total Environ 2006 Aug 12;367(2-3):544-58. Epub 2006 May 12.

Environment Canada, National Water Research Institute, 867 Lakeshore Road, P. O. Box 5050, Burlington, Ontario, Canada L7R 4A6.

Over the last ten years there have been reports of pharmaceuticals and personal care product (PPCP) residuals in municipal wastewater treatment plant (WWTP) effluents. The principle goal of this study was specifically to expand and in some cases establish a Canadian database for the presence of selected acidic drugs, triclosan, polycyclic musks, and selected estrogens in MWWTP influent and effluent. The impact of treatment configuration (e.g. lagoons, conventional activated sludge (CAS), and CAS followed by media filtration (CAS+filtration)) was also examined. For CAS systems, the most prevalent treatment type, the effect of operating temperature and SRT was evaluated. Selected PPCPs included ten acidic pharmaceuticals (i.e. a group of pharmaceuticals that are extractable at a pH of 2 or less), triclosan, five polycyclic musks and two estrogens. The pharmaceuticals and musks were selected on the basis of levels of use in Canada; reported aquatic toxicity effects; and the ability to analyze for the compounds at low levels. Twelve MWWTPs discharging into the Thames River, the second largest river in southwestern Ontario, were surveyed. The only common characteristic of acidic drugs is their extraction pH as they differ in their intended biological function and chemical structure. Many organics degraded by WWTP processes benefit from warm temperatures and long SRTs so the impact of these variables warranted additional attention. Influent concentrations and reductions for acidic drugs reported by this study were compared to other Canadian studies, when available, and European investigations. The data of this study seems consistent with other reports. Ten acidic drugs were considered by this study. Three were consistently present at non-quantifiable levels (e.g. CLF, FNP and FNF). Additionally, one analyte, SYL, presented results that were so inconsistent that the values were not analysed. The remaining six acidic pharmaceuticals were placed into three categories. IBU and NPX members of the first category had consistently high reductions. At the level of reduction achieved (i.e. median reduction of greater than 93%) and any effect of treatment type or operating characteristics would be subtle and non-discernable given the analytical noise. In the second group are KTP and IND, and definitive comments are difficult to make on the impact of treatment type and operational considerations due to a sparse data set (i.e. many influent values were at non-quantifiable concentrations). Median reductions were in the 23% to 44% range. In the last category are GMF and DCF which have median reductions of 66% and -34%, respectively. Several negative reduction values in the data set (i.e. twelve of twenty six sampling events) suggest that DCF may be deconjugated under certain conditions. This warrants further evaluation when analytical methods for measuring human metabolites of DCF are available. For both GMF and DCF, reduction does not appear to be strongly influenced by SRTs up to 15 days, while SRTs over 30 days were associated with more frequent non-quantifiable effluent levels of DCF. This would suggest that better treatment would be provided by lagoons and CAS systems with extended aeration. Preliminary data suggests that temperature does not play a strong role in the reduction of these compounds. Triclosan (TCL) was detected at concentrations of 0.01-4.01 microg/L in influent samples and 0.01-0.324 microg/L in effluent samples. Reduction of TCL ranged from 74% to 98%. Lagoon treatment seems to be the best TCL reduction as it was present in the influent and effluent at quantifiable and non-quantifiable concentrations, respectively, on nine of nine sampling occasions. Influent and reduction values of five polycyclic musks (e.g. ADBI, AHMI, ATII, HHCB, and AHTN) were examined over the course of this study. AHMI was predominantly present at non-quantifiable concentrations. HHCB and AHTN were present at the highest concentrations. A comparison between Canadian values and those of European studies indicate that in general polycyclic musk concentrations in Canadian MWWTP effluents are 5-10 times lower. More extensive European and Canadian databases would be useful in confirming this initial observation. Median reductions for the five remaining musks range between 37% and 65% in CAS systems. CAS+filtration systems would be expected to have higher reductions if musks were bound to the effluent solids. This trend is not apparent but this may be due to the small size of the data set. In lagoon systems, musk reduction for HHCB and AHTN are approximately 98-99%. For ADBI and ATII musk, there are no numerical reduction values as most often the effluent concentration was non-quantifiable. In some instances, both the influent and effluent concentrations were non-quantifiable. The hormones 17-beta-estradiol (E2) and estrone (E1) were detected at concentrations of 0.006 to 0.014 and 0.016 to 0.049 microg/L, respectively. E2 was not detected in any effluent samples (<0.005 microg/L) whereas E1 was detected in effluent samples from CAS treatment plants (median of 0.008 microg/L), and in one sample from lagoons. These data demonstrate that there are detectable levels of PPCPs entering Canadian waterways at trace levels, and that only some of these compounds are being reduced in a significant proportion by municipal wastewater treatment processes.
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http://dx.doi.org/10.1016/j.scitotenv.2006.03.021DOI Listing
August 2006

Isolation of compounds from bleached kraft mill recovery condensates associated with reduced levels of testosterone in mummichog (Fundulus heteroclitus).

Environ Toxicol Chem 2002 Jul;21(7):1359-67

Aquatic Ecosystem Protection Research Branch, National Water Research Institute, Environment Canada, Burlington, Ontario.

Previous studies have identified chemical recovery condensates as a primary source of hormonally active substances within a Canadian bleached kraft pulp mill. Although reverse osmosis treatment of condensates raises the exposure threshold that alters circulating levels of testosterone in mummichog (Fundulus heteroclitus), the responsible chemicals have not been characterized. In this study, a solid-phase extraction (SPE) method was developed to isolate chemical recovery condensate extractives for evaluation of hormonal activity. Condensates generated during softwood and hardwood pulp production were investigated for their relative potential to affect both circulating and gonadal production of sex steroids in mummichog. Mummichog were exposed to whole condensates, extracts from suspended particulates (> 1 microm), two fractions from SPE, and residual condensates after SPE. The distribution of bioactivity among condensate fractions was similar for both wood furnishes. In both sexes, significant depressions in circulating testosterone and in in vitro gonadal testosterone production were associated with exposure to whole condensates, particulate extracts, one SPE fraction, and residual material after SPE. An optimized SPE method subsequently demonstrated complete recovery of polar, bioavailable chemicals that reduced testosterone levels in both sexes. Characterizations of active fractions by gas chromatography-mass spectrometry (GC-MS) showed the presence of extractives with molecular masses > or = 240 amu possessing functionalities consistent with lignin degradation products. This study provides the first isolation of chemicals derived from pulp production associated with impaired reproductive performance in fish.
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July 2002
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