This page has only limited features, please log in for full access.
Nanotoxicology research commonly utilizes pristine nanomaterials for toxicity assessment, which may not be perfectly representative of what is released into environmental systems. The goal of the present study was to develop a method to simulate human weathering of silver-containing textiles. To achieve this goal the roles of physical and chemical stress on X-Static® containing athletic textiles were investigated and compared to data collected from human weathering experiments and literature. Chemical weathering methods (artificial sweat) were used independently and alongside physical weathering methods (3D printed stretching and abrasion instruments). Non-weathered control textiles were found to release 29 ± 11 mg Ag/kg of textile into wash water effluent (ICP-MS), with 16% being released as ionic silver (ICP-MS) and the rest as metallic nanomaterials, nanosheets, and particulates of varying size (SEM/XANES). Real and simulated human weathered textiles released similar amounts of total silver (67 ± 11 mg Ag/kg, 84 ± 13 mg Ag/kg respectively) with the silver released being composed of ionic (1.5%, 2%) and a mixture of metallic and chlorinated nanomaterials, nanosheets, and particulates. The method was shown to effectively detach environmentally representative silver materials from silver-containing textiles and can provide such materials for future studies on the assessment of their fate, transport, and toxicity.
David Patch; Iris Koch; Derek Peloquin; Denis O'Carroll; Kela Weber. Development and validation of a method for the weathering and detachment of representative nanomaterials from conventional silver-containing textiles. Chemosphere 2021, 284, 131269 .
AMA StyleDavid Patch, Iris Koch, Derek Peloquin, Denis O'Carroll, Kela Weber. Development and validation of a method for the weathering and detachment of representative nanomaterials from conventional silver-containing textiles. Chemosphere. 2021; 284 ():131269.
Chicago/Turabian StyleDavid Patch; Iris Koch; Derek Peloquin; Denis O'Carroll; Kela Weber. 2021. "Development and validation of a method for the weathering and detachment of representative nanomaterials from conventional silver-containing textiles." Chemosphere 284, no. : 131269.
Per- and polyfluoroalkyl substances (PFAS) are manmade, fluorinated organic chemicals which have been identified as persistent organic pollutants. PFAS have surface active properties that have made them suitable for applications in oil- and water-resistant products, as well as many firefighting foams. No on-site remediation strategies exist to treat PFAS impacted soils. Mechanochemical remediation of PFOS- and PFOA-amended sand via a planetary ball mill was studied. The effect of sand mass, KOH as a co-milling reagent, and water saturation on the degradation of PFOA and PFOS was evaluated. By four hours of milling concentrations were reduced by up to 98% for PFOS-amended dry sand and 99% for PFOA-amended dry sand without the addition of a co-milling reagent. Water saturation was determined to be a significant hindrance on the mechanochemical destruction of PFOS and PFOA. A maximum of 89% of fluoride was recovered from PFOS-amended sand when KOH was used as a co-milling reagent. It is hypothesized that reactive particles generated from the fracture of sand grains react with PFAS molecules to initiate destruction, which can result in full defluorination. Milling experiments were also conducted on soils from a Canadian firefighting training area (FFTA), demonstrating that PFOS concentrations can be reduced by up to 96% in site soils. For the first time, ball milling for the remediation of PFAS in environmental media has been demonstrated using amended sand and legacy soils from a FFTA.
Lauren P. Turner; Bernard H. Kueper; Kevin M. Jaansalu; David J. Patch; Nick Battye; Omneya El-Sharnouby; Kevin G. Mumford; Kela P. Weber. Mechanochemical remediation of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) amended sand and aqueous film-forming foam (AFFF) impacted soil by planetary ball milling. Science of The Total Environment 2020, 765, 142722 .
AMA StyleLauren P. Turner, Bernard H. Kueper, Kevin M. Jaansalu, David J. Patch, Nick Battye, Omneya El-Sharnouby, Kevin G. Mumford, Kela P. Weber. Mechanochemical remediation of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) amended sand and aqueous film-forming foam (AFFF) impacted soil by planetary ball milling. Science of The Total Environment. 2020; 765 ():142722.
Chicago/Turabian StyleLauren P. Turner; Bernard H. Kueper; Kevin M. Jaansalu; David J. Patch; Nick Battye; Omneya El-Sharnouby; Kevin G. Mumford; Kela P. Weber. 2020. "Mechanochemical remediation of perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) amended sand and aqueous film-forming foam (AFFF) impacted soil by planetary ball milling." Science of The Total Environment 765, no. : 142722.
This study explored smouldering combustion for remediating PFAS-impacted granular activated carbon (GAC) and PFAS-contaminated soil. GAC, both fresh and PFAS-loaded, was employed as the supplemental fuel supporting smouldering in mixtures with clean sand (≈175 mg PFAS/kg), with PFAS-spiked, laboratory-constructed soil (≈4 mg PFAS/kg), and with a PFAS-impacted field soil (≈0.2 mg PFAS/kg). The fate of PFAS and fluorine was quantified with soil and emissions analyses, including targeted and non-targeted PFAS as well as hydrogen fluoride and total organic fluorine. Results demonstrated that exceeding 35 g GAC/kg soil resulted in self-sustained smouldering with temperatures exceeding 900˚C. Post-treatment PFAS concentrations of the treated soil were near (2 experiments) or below (7 experiments) detection limits (0.0005 mg/kg). 44% of the initial PFAS on GAC underwent full destruction, compared to 16% of the PFAS on soil. Less than 1% of the initial PFAS contamination on GAC or soil was emitted as PFAS compounds in the quantifiable analytical suite. Results suggest that the rest were emitted as altered, shorter-chain PFAS and volatile fluorinated compounds, which were scrubbed effectively with GAC. Total organic fluorine analysis proved useful for PFAS-loaded GAC in sand, however analyzing soils suffered from interference from non-PFAS compounds. Overall, this study demonstrated that smouldering has significant potential as an effective remediation technique for PFAS-impacted soils and PFAS-laden GAC.
Alexandra L. Duchesne; Joshua K. Brown; David J. Patch; David W. Major; Kela P. Weber; Jason Ian Gerhard. Remediation of PFAS-Contaminated Soil and Granular Activated Carbon by Smoldering Combustion. Environmental Science & Technology 2020, 54, 12631 -12640.
AMA StyleAlexandra L. Duchesne, Joshua K. Brown, David J. Patch, David W. Major, Kela P. Weber, Jason Ian Gerhard. Remediation of PFAS-Contaminated Soil and Granular Activated Carbon by Smoldering Combustion. Environmental Science & Technology. 2020; 54 (19):12631-12640.
Chicago/Turabian StyleAlexandra L. Duchesne; Joshua K. Brown; David J. Patch; David W. Major; Kela P. Weber; Jason Ian Gerhard. 2020. "Remediation of PFAS-Contaminated Soil and Granular Activated Carbon by Smoldering Combustion." Environmental Science & Technology 54, no. 19: 12631-12640.
Diffusion of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) through 0.1 mm and 0.75 mm LLDPE and 0.1 mm and 0.75 mm LLDPE coextruded with ethyl vinyl alcohol (denoted as CoEx) at room temperature (23 °C), 35 °C, and 50 °C is examined. These tests had negligible source depletion throughout the monitoring period, indicating limited contaminant partitioning and diffusion through the LLDPE. At 483 days, 23 °C receptor PFOA and PFOS concentrations, cr, were <8 μg/L (cr/co < 3.2 × 10−4) for all tests, and at 399 days elevated temperature receptor concentrations were < 0.4 μg/L (cr/co < 1.6 × 10−5) at 35 °C and <0.5 μg/L (cr/co < 2.0 × 10−5) at 50 °C for both PFOA and PFOS. LLDPE partitioning coefficient, Sgf was 0.9–1.4 (PFOA) and 2.8–5.3 (PFOS) based on sorption tests at 23 °C. Based on the best estimates of permeation coefficient, PgCoEx, for CoEx was consistently lower than PgLLDPE. For PFOA, CoEx had PgCoEx < 0.26 × 10−16 m2/s at 23 °C, <11 × 10−16 m2/s (35 °C), and < 10 × 10−16 m2/s (50 °C) while LLDPE had PgLLDPE < 3.1 × 10−16 m2/s (23 °C), <13 × 10−16 m2/s (35 °C), and <19 × 10−16 m2/s (50 °C). For PFOS, CoEx and LLDPE had PgCoEx < 0.55 × 10−16 m2/s and PgLLDPE < 3.2 × 10−16 m2/s (23 °C), PgCoEx < 8.3 × 10−16 m2/s and PgLLDPE < 40 × 10−16 m2/s (35 °C), and PgCoEx < 8.2 × 10−16 m2/s and PgLLDPE < 52 × 10−16 m2/s (50 °C). These values are preliminary and may change (e.g., decrease) as more data comes available over time. The Pg values deduced for PFOA and PFOS are remarkably lower than those reported for other contaminants of concern, excepting BPA, which exhibits similar behaviour.
V. Di Battista; R. Kerry Rowe; D. Patch; K. Weber. PFOA and PFOS diffusion through LLDPE and LLDPE coextruded with EVOH at 22 °C, 35 °C, and 50 °C. Waste Management 2020, 117, 93 -103.
AMA StyleV. Di Battista, R. Kerry Rowe, D. Patch, K. Weber. PFOA and PFOS diffusion through LLDPE and LLDPE coextruded with EVOH at 22 °C, 35 °C, and 50 °C. Waste Management. 2020; 117 ():93-103.
Chicago/Turabian StyleV. Di Battista; R. Kerry Rowe; D. Patch; K. Weber. 2020. "PFOA and PFOS diffusion through LLDPE and LLDPE coextruded with EVOH at 22 °C, 35 °C, and 50 °C." Waste Management 117, no. : 93-103.
For irradiation experiments (e.g., of per- and polyfluoroalkyl substances), values of nuclear particle flux and absorbed dose rates were obtained for the Safe LOW-POwer Kritical Experiment-2 (SLOWPOKE-2) nuclear reactor at the Royal Military College of Canada using extensive simulations of the reactor core via the Monte Carlo N-Particle code, version 6 (MCNP6). Calculations from this work were compared to data from previously conducted experimental and simulation work to ensure simulation fidelity. In addition, reactor core burnup calculations were conducted using the fuel-depletion capability in MCNP6.1 to address the 30+ years of SLOWPOKE-2 reactor use. The combined absorbed dose rate in the inner irradiation sites was simulated to be 36 ± 1 kGy h−1 at a 10-kW(thermal) power setting, specifically, 20 ± 6 kGy h−1 from neutrons and 16 ± 5 kGy h−1 from photons.
J. C. Rook; K. P. Weber; E. C. Corcoran. Advanced MCNP Simulation of the Neutron and Photon Flux and Absorbed Dose Rates for the SLOWPOKE-2 Nuclear Reactor at the Royal Military College of Canada. Nuclear Technology 2020, 206, 1861 -1874.
AMA StyleJ. C. Rook, K. P. Weber, E. C. Corcoran. Advanced MCNP Simulation of the Neutron and Photon Flux and Absorbed Dose Rates for the SLOWPOKE-2 Nuclear Reactor at the Royal Military College of Canada. Nuclear Technology. 2020; 206 (12):1861-1874.
Chicago/Turabian StyleJ. C. Rook; K. P. Weber; E. C. Corcoran. 2020. "Advanced MCNP Simulation of the Neutron and Photon Flux and Absorbed Dose Rates for the SLOWPOKE-2 Nuclear Reactor at the Royal Military College of Canada." Nuclear Technology 206, no. 12: 1861-1874.
The microbial characteristics of four vegetated and one unplanted wood-chip bioreactors treating greenhouse effluent were investigated in a continuous experiment operated for over 2.5 years. The bioreactors were designed to reduce nitrate concentrations via naturally induced microbial denitrification. The vegetation type and reactor depth were both found to be significant factors in defining the mixed microbial activity. However, a consistent correlation between the abundance of the denitrifying communities and reactor depth could not be found across all reactors. The media samples from the unit planted with Typha angustifolia displayed higher microbial activities compared with the other reactors. This plant’s root-associated bacteria also demonstrated the greatest copies of the denitrifying genes nirK and nosZ. The most abundant denitrifier communities and those encoding the nosZ gene were found in the unplanted reactor, followed by the T. angustifolia unit. The T. angustifolia reactor demonstrated greater microbial activity and denitrification capacity at the depth of 20 cm, while the greatest denitrification capacity in the unplanted reactor was found at the depth of 60 cm. These findings indicated the importance of the T. angustifolia rhizosphere to support microbial community establishment and growth in the vicinity of the plant’s roots, although those populations may eventually develop in an unplanted environment.
Soheil Fatehi-Pouladi; Bruce C. Anderson; Brent Wootton; Sarah J. Wallace; Sonja Bissegger; Lloyd Rozema; Kela P. Weber. Influence of Plant Species on Microbial Activity and Denitrifier Population Development in Vegetated Denitrifying Wood-Chip Bioreactors. Plants 2020, 9, 289 .
AMA StyleSoheil Fatehi-Pouladi, Bruce C. Anderson, Brent Wootton, Sarah J. Wallace, Sonja Bissegger, Lloyd Rozema, Kela P. Weber. Influence of Plant Species on Microbial Activity and Denitrifier Population Development in Vegetated Denitrifying Wood-Chip Bioreactors. Plants. 2020; 9 (3):289.
Chicago/Turabian StyleSoheil Fatehi-Pouladi; Bruce C. Anderson; Brent Wootton; Sarah J. Wallace; Sonja Bissegger; Lloyd Rozema; Kela P. Weber. 2020. "Influence of Plant Species on Microbial Activity and Denitrifier Population Development in Vegetated Denitrifying Wood-Chip Bioreactors." Plants 9, no. 3: 289.
Per- and polyfluoroalkyl substances (PFAS) are presently essential ingredients in aqueous film forming foam (AFFF) used for fire-fighting, but are also pervasive environmental contaminants. The use and subsequent release and transport of AFFF in the ocean environment from marine vessels has not been studied to date. A numerical model (Delft3D) was rigorously calibrated and validated for the hydrodynamics, and used to predict the transport of PFAS released instantaneously into a large harbour (Halifax Harbour, Nova Scotia) that is representative of coastal environments in eastern Canada and other parts of the world. The numerical model results indicate that PFAS released in the presence of strong winds and waves during a storm will travel up to 31 km in 2 days, approximately 40% farther than PFAS release during a time period dominated by tidal currents with light winds and small waves (<1 m). After a 10 day simulation, PFAS levels from release sites in the Inner Harbour were higher (40–60 μg/L) compared to PFAS levels from the Outer Harbour release site which had decreased to low levels (<1 μg/L) during a non-storm period. Along shorelines within the Harbour, PFAS concentrations remained elevated after 12 h (40–500 μg/L) and 48 h (2–300 μg/L). These concentrations are within the range of PFAS guidance values for recreational water use. The methods described here are relevant to studies of PFAS dispersion and transport in other coastal areas, and could be used to determine best practices for applications of AFFF in the coastal environment.
Linda M. Hodgkins; Ryan P. Mulligan; John M. McCallum; Kela P. Weber. Modelling the transport of shipborne per- and polyfluoroalkyl substances (PFAS) in the coastal environment. Science of The Total Environment 2018, 658, 602 -613.
AMA StyleLinda M. Hodgkins, Ryan P. Mulligan, John M. McCallum, Kela P. Weber. Modelling the transport of shipborne per- and polyfluoroalkyl substances (PFAS) in the coastal environment. Science of The Total Environment. 2018; 658 ():602-613.
Chicago/Turabian StyleLinda M. Hodgkins; Ryan P. Mulligan; John M. McCallum; Kela P. Weber. 2018. "Modelling the transport of shipborne per- and polyfluoroalkyl substances (PFAS) in the coastal environment." Science of The Total Environment 658, no. : 602-613.
The recent commercialisation of antimicrobial textiles has resulted in concern regarding the incidental release of silver nanomaterials (Ag-NMs) to the environment.
Vincent Gagnon; Mark Button; Hardiljeet K. Boparai; Michelle Nearing; Denis M. O'Carroll; Kela P. Weber. Influence of realistic wearing on the morphology and release of silver nanomaterials from textiles. Environmental Science: Nano 2018, 6, 411 -424.
AMA StyleVincent Gagnon, Mark Button, Hardiljeet K. Boparai, Michelle Nearing, Denis M. O'Carroll, Kela P. Weber. Influence of realistic wearing on the morphology and release of silver nanomaterials from textiles. Environmental Science: Nano. 2018; 6 (2):411-424.
Chicago/Turabian StyleVincent Gagnon; Mark Button; Hardiljeet K. Boparai; Michelle Nearing; Denis M. O'Carroll; Kela P. Weber. 2018. "Influence of realistic wearing on the morphology and release of silver nanomaterials from textiles." Environmental Science: Nano 6, no. 2: 411-424.
Assessing the extent to which emerging contaminants (ECs) such as perfluoroalkyl and polyfluoroalkyl substances (PFAS) have been released into the environment is one of the foundations for developing effective management and remediation strategies for impacted sites. PFAS are known to have caused the contamination of soil, groundwater, and surface water as a result of aqueous film forming foam (AFFF) being accidentally or intentionally released into the environment. To date, the scope of the issue has not been evaluated in Canada. In this study we developed a framework, in the form of a decision tree, to estimate the number of potentially PFAS impacted airport sites in Canada as a result of AFFF releases. The screening process was completed using publicly available resources including airport websites, the Canadian Owners and Pilots Association website, Sky Vector, Transport Safety Board of Canada aviation investigation reports, the Aviation Safety Network website, and Google maps. The methodology presented in this study could be used to identify additional PFAS impacted sites in Canada or other jurisdictions worldwide. 2071 airport/heliport sites in Canada were investigated with indications that 152 (7%) of these sites likely have PFAS contamination as a result of the use of AFFF at firefighter training areas (FFTAs) and/or accidents where fires occurred. In addition, another 268 sites (13%) were identified as possibly impacted with PFASs primarily as a result of the location having the ability to store and dispense petroleum products, and therefore having AFFF systems onsite. Surficial geology was also identified for all sites determined to likely have PFAS contamination. An estimated 42.8% had surficial geology composed of sand, 27% had clay, 19.7% organic-based, with the remaining sites found on cryosols or rock. Methodological validation was also completed. The procedure used in this study successfully predicted occurrences of PFAS contamination at 25 sites where contamination, as a result of AFFF use, was confirmed by Canadian governmental departments. For these 25 sites, the distance from potential release areas to the nearest surface water was calculated. Five of the sites were within 200 meters of surface water, 19 were within one kilometer, and all 25 were within 2.5 kilometers. This suggests that surface water may have been historically impacted by PFAS at as many as 152 to 420 different airport locations in Canada.
Shawn A. Milley; Iris Koch; Patricia Fortin; Jeremy Archer; David Reynolds; Kela P. Weber. Estimating the number of airports potentially contaminated with perfluoroalkyl and polyfluoroalkyl substances from aqueous film forming foam: A Canadian example. Journal of Environmental Management 2018, 222, 122 -131.
AMA StyleShawn A. Milley, Iris Koch, Patricia Fortin, Jeremy Archer, David Reynolds, Kela P. Weber. Estimating the number of airports potentially contaminated with perfluoroalkyl and polyfluoroalkyl substances from aqueous film forming foam: A Canadian example. Journal of Environmental Management. 2018; 222 ():122-131.
Chicago/Turabian StyleShawn A. Milley; Iris Koch; Patricia Fortin; Jeremy Archer; David Reynolds; Kela P. Weber. 2018. "Estimating the number of airports potentially contaminated with perfluoroalkyl and polyfluoroalkyl substances from aqueous film forming foam: A Canadian example." Journal of Environmental Management 222, no. : 122-131.
The impacts to microbial function, overall performance and eventual fate were assessed for triclosan (TCL) and sulfamethoxazole (SMX) in intensified (re-circulating) vertical subsurface flow (VSSF) constructed wetlands (CWs). The potential toxicity of each pharmaceutical to the intrinsic microbial communities was first assessed over a wide exposure range (0–1000 μg/l) via an ex-situ dose-response assay to estimate the concentration at which adverse effects were likely to occur. Based on these results an acute (7 day) in-situ exposures (500 μg/l) were then performed and impacts to the mesocosm systems monitored for 1 month via community-level physiological profiling (CLPP) alongside chemical oxygen demand (COD) removal rates and a range of water quality, and hydrological parameters. Despite the clear potential for negative impacts to microbial function from both compounds observed at 100 μg/l in the ex-situ dose-response test, no impacts were observed for the 500 μg/l in-situ exposure in the VSSF mesocosms. COD removal, water chemistry, plant health, and hydrological parameters did not significantly change in response to the in-situ exposure. In terms of fate, the removal efficiency for both TCL and SMX was high (>80%) after 1 h and complete removal (>99.7%) was observed after 168 h. Following the in-situ exposure, and subsequent one month effects-monitoring period, the mesocosms were decommissioned with the media biofilm spatially assessed for organic content as well as TCL and SMX concentrations. TCL and SMX were found to have persisted in the media and demonstrated spatial variation with an overall 2–20% and 5–6% recovered respectively. This suggests that biofilm bound TCL and SMX were biologically degraded in VSSF CWs, however may also accumulate in the biofilm if TCL and SMX are maintained in the influent. These results reinforce the robustness and potential of constructed wetlands for the treatment of pharmaceutical and personal care product (PPCP) contaminated wastewater.
Mark Button; Katryn Cosway; Jessie Sui; Kela Weber. Impacts and fate of triclosan and sulfamethoxazole in intensified re-circulating vertical flow constructed wetlands. Science of The Total Environment 2018, 649, 1017 -1028.
AMA StyleMark Button, Katryn Cosway, Jessie Sui, Kela Weber. Impacts and fate of triclosan and sulfamethoxazole in intensified re-circulating vertical flow constructed wetlands. Science of The Total Environment. 2018; 649 ():1017-1028.
Chicago/Turabian StyleMark Button; Katryn Cosway; Jessie Sui; Kela Weber. 2018. "Impacts and fate of triclosan and sulfamethoxazole in intensified re-circulating vertical flow constructed wetlands." Science of The Total Environment 649, no. : 1017-1028.
Analysis of water table fluctuations can provide important insight into the hydraulic properties and structure of a coastal aquifer system including the connectivity between the aquifer and ocean. This study presents an improved approach for characterizing a permeable heterogeneous coastal aquifer system through analysis of the propagation of the tidal signal, as well as offshore storm pulse signals through a coastal aquifer. Offshore storms produce high wave activity, but are not necessarily linked to significant onshore precipitation. In this study, we focused on offshore storm events during which no onshore precipitation occurred. Extensive groundwater level data collected on a sand barrier island (Sable Island, NS, Canada) show non-uniform discontinuous propagation of the tide and offshore storm pulse signals through the aquifer with isolated inland areas showing enhanced response to both oceanic forcing signals. Propagation analysis suggests that isolated inland water table fluctuations may be caused by localized leakage from a confined aquifer that is connected to the ocean offshore but within the wave setup zone. Two-dimensional groundwater flow simulations were conducted to test the leaky confined-unconfined aquifer conceptualization and to identify the effect of key parameters on tidal signal propagation in leaky confined-unconfined coastal aquifers. This study illustrates that analysis of offshore storm signal propagation, in addition to tidal signal propagation, provides a valuable and low resource approach for large-scale characterization of permeable heterogeneous coastal aquifers. Such an approach is needed for the effective management of coastal environments where water resources are threatened by human activities and the changing climate.
Victoria Trglavcnik; Dean Morrow; Kela P. Weber; Ling Li; Clare E. Robinson. Analysis of Tide and Offshore Storm-Induced Water Table Fluctuations for Structural Characterization of a Coastal Island Aquifer. Water Resources Research 2018, 54, 2749 -2767.
AMA StyleVictoria Trglavcnik, Dean Morrow, Kela P. Weber, Ling Li, Clare E. Robinson. Analysis of Tide and Offshore Storm-Induced Water Table Fluctuations for Structural Characterization of a Coastal Island Aquifer. Water Resources Research. 2018; 54 (4):2749-2767.
Chicago/Turabian StyleVictoria Trglavcnik; Dean Morrow; Kela P. Weber; Ling Li; Clare E. Robinson. 2018. "Analysis of Tide and Offshore Storm-Induced Water Table Fluctuations for Structural Characterization of a Coastal Island Aquifer." Water Resources Research 54, no. 4: 2749-2767.
Microbial degradation is an important pathway during the removal of pharmaceuticals in constructed wetlands (CWs). However, the effects of CW design, plant presence, and different plant species on the microbial community in CWs have not been fully explored. This study aims to investigate the microbial community metabolic function of different types of CWs used to treat ibuprofen via community-level physiological profiling (CLPP) analysis. We studied the interactions between three CW designs (unsaturated, saturated and aerated) and six types of mesocosms (one unplanted and five planted, with Juncus, Typha, Berula, Phragmites and Iris) treating synthetic wastewater. Results show that the microbial activity and metabolic richness found in the interstitial water and biofilm of the unsaturated designs were lower than those of the saturated and aerated designs. Compared to other CW designs, the aerated mesocosms had the highest microbial activity and metabolic richness in the interstitial water, but similar levels of biofilm microbial activity and metabolic richness to the saturated mesocosms. In all three designs, biofilm microbial metabolic richness was significantly higher (p < .05) than that of interstitial water. Both the interstitial water and biofilm microbial community metabolic function were influenced by CW design, plant presence and species, but design had a greater influence than plants. Moreover, canonical correlation analysis indicated that biofilm microbial communities in the three designs played a key role in ibuprofen degradation. The important factors identified as influencing ibuprofen removal were microbial AWCD (average well color development), microbial metabolic richness, and the utilization of amino acids and amine/amides. The enzymes associated with co-metabolism of L-arginine, L-phenyloalanine and putrescine may be linked to ibuprofen transformations. These results provide useful information for optimizing the operational parameters of CWs to improve ibuprofen removal.
Liang Zhang; Tao Lyu; Yang Zhang; Mark Button; Carlos A Arias; Kela P. Weber; Hans Brix; Pedro N. Carvalho. Impacts of design configuration and plants on the functionality of the microbial community of mesocosm-scale constructed wetlands treating ibuprofen. Water Research 2018, 131, 228 -238.
AMA StyleLiang Zhang, Tao Lyu, Yang Zhang, Mark Button, Carlos A Arias, Kela P. Weber, Hans Brix, Pedro N. Carvalho. Impacts of design configuration and plants on the functionality of the microbial community of mesocosm-scale constructed wetlands treating ibuprofen. Water Research. 2018; 131 ():228-238.
Chicago/Turabian StyleLiang Zhang; Tao Lyu; Yang Zhang; Mark Button; Carlos A Arias; Kela P. Weber; Hans Brix; Pedro N. Carvalho. 2018. "Impacts of design configuration and plants on the functionality of the microbial community of mesocosm-scale constructed wetlands treating ibuprofen." Water Research 131, no. : 228-238.
The objective of this study was to compare the microbial community metabolic function from both unsaturated and saturated constructed wetland mesocosms (CWs) when treating the pesticide tebuconazole. The comparison was performed for both interstitial water and substrate biofilm by community level physiological profiling (CLPP) via BIOLOG™ EcoPlates. For each CW design (saturated or unsaturated), six mesocosms were established including one unplanted and five planted individually with either Juncus effusus, Typha latifolia, Berula erecta, Phragmites australis or Iris pseudacorus. Microbial activity and metabolic richness of interstitial water from unsaturated CWs were significantly lower than that from saturated CWs. However, in general, the opposite result was observed for biofilm samples. Wetland plants promoted significantly higher biofilm microbial activity and metabolic richness than unplanted CWs in both CW designs. Differences in the microbial community functional profiles between plant species were only found for saturated CWs. Biofilm microbial metabolic richness was generally statistically higher than that of interstitial water in both unsaturated (1.4-24 times higher) and saturated (1.2-1.7 times higher) CWs. Carbon source (guild) utilization patterns were generally different between interstitial water and biofilm samples. Functionality of the biofilm microbial community was positively correlated to the removal of all pollutants (TN, NH4+-N, TP, TOC and tebuconazole) for both unsaturated and saturated CWs, suggesting the biofilm plays a more important role in pollutant removal than the interstitial water microbial community. Thus, merely observing the interstitial water microbial communities may underestimate the role of the microbial community in CW performance. Interestingly, the ability for the biofilm microbial community to utilize amino acids and amines/amides was positively correlated with tebuconazole removal in all system types.
Tao Lv; Pedro N. Carvalho; Liang Zhang; Yang Zhang; Mark Button; Carlos A Arias; Kela P. Weber; Hans Brix. Functionality of microbial communities in constructed wetlands used for pesticide remediation: Influence of system design and sampling strategy. Water Research 2017, 110, 241 -251.
AMA StyleTao Lv, Pedro N. Carvalho, Liang Zhang, Yang Zhang, Mark Button, Carlos A Arias, Kela P. Weber, Hans Brix. Functionality of microbial communities in constructed wetlands used for pesticide remediation: Influence of system design and sampling strategy. Water Research. 2017; 110 ():241-251.
Chicago/Turabian StyleTao Lv; Pedro N. Carvalho; Liang Zhang; Yang Zhang; Mark Button; Carlos A Arias; Kela P. Weber; Hans Brix. 2017. "Functionality of microbial communities in constructed wetlands used for pesticide remediation: Influence of system design and sampling strategy." Water Research 110, no. : 241-251.
Tao Lv; Yang Zhang; Pedro N. Carvalho; Liang Zhang; Mark Button; Carlos A Arias; Kela P. Weber; Hans Brix. Microbial community metabolic function in constructed wetland mesocosms treating the pesticides imazalil and tebuconazole. Ecological Engineering 2017, 98, 378 -387.
AMA StyleTao Lv, Yang Zhang, Pedro N. Carvalho, Liang Zhang, Mark Button, Carlos A Arias, Kela P. Weber, Hans Brix. Microbial community metabolic function in constructed wetland mesocosms treating the pesticides imazalil and tebuconazole. Ecological Engineering. 2017; 98 ():378-387.
Chicago/Turabian StyleTao Lv; Yang Zhang; Pedro N. Carvalho; Liang Zhang; Mark Button; Carlos A Arias; Kela P. Weber; Hans Brix. 2017. "Microbial community metabolic function in constructed wetland mesocosms treating the pesticides imazalil and tebuconazole." Ecological Engineering 98, no. : 378-387.
Mark Button; Hannele Auvinen; Frederik Van Koetsem; Baharak Hosseinkhani; Diederik Rousseau; Kela P. Weber; Gijs Du Laing. Susceptibility of constructed wetland microbial communities to silver nanoparticles: A microcosm study. Ecological Engineering 2016, 97, 476 -485.
AMA StyleMark Button, Hannele Auvinen, Frederik Van Koetsem, Baharak Hosseinkhani, Diederik Rousseau, Kela P. Weber, Gijs Du Laing. Susceptibility of constructed wetland microbial communities to silver nanoparticles: A microcosm study. Ecological Engineering. 2016; 97 ():476-485.
Chicago/Turabian StyleMark Button; Hannele Auvinen; Frederik Van Koetsem; Baharak Hosseinkhani; Diederik Rousseau; Kela P. Weber; Gijs Du Laing. 2016. "Susceptibility of constructed wetland microbial communities to silver nanoparticles: A microcosm study." Ecological Engineering 97, no. : 476-485.
The field of treatment wetlands (TWs) is rapidly expanding and, arguably, is tasked with studying and understanding one of the most complex water treatment systems available. Microbial communities are generally considered to be responsible for the majority of wastewater constituent degradation in TWs. However, they are also known to be spatially heterogeneous, temporally dynamic, as well as structurally and functionally diverse. Presented here is a meta-analysis of all peer reviewed TW journal articles which utilized a microbial community assessment methodology over the period of 1988 to July 2016. A total of 1101 papers were reviewed, 512 from 1988 to 2012, 215 of which included a microbial community assessment aspect and were subsequently classified as representing past research, and 589 from 2013 to July 2016, 196 of which were classified as representing current TW microbial community research. In general, TW microbial community research has increased over time, with a marked surge in the past four years. Microbial community structure is currently the most commonly used methodological type followed by activity, enumeration and function, respectively. Areas of research focus included nitrogen transformations (156), organic degradation (33), and emerging contaminants (32), with general characterization studies also accounting for a significant proportion (243). Microbial communities from a range of TW systems have been investigated over the last four years with meso-scale (10–1000 L) being the most commonly studied system size followed by large-scale (>100,000 L), micro-scale (<10 L), and pilot-scale (1000–100,000 L). Free water surface flow (SF), horizontal subsurface flow (HF), and vertical flow (VF) systems are being studied in approximately equal proportions with the majority of studies focused on gaining fixed media/biofilm samples for analysis (rather than from the rhizosphere or interstitial water). Looking at efforts from a regional perspective shows Asia to be publishing the majority of research with a main focus on VF systems and structural community assessment. European and North American studies are generally more evenly distributed among structure, function, activity, and enumeration with the majority of studies completed on HF systems. South America, Africa, and Oceania published fewer studies but focused on structural community assessment with a selection of HF, SF and VF investigations. Great strides are being made in the field of microbial community assessment in TWs with functional assessment methods being developed, better utilized, and being related directly to water treatment. The use of high-powered metagenomics sequencing such as Illumina HiSeq instrumentation is on the rise, as is the development and utilization of functional assays such as DNA microarrays and community level physiological profiling allowing for more complete community assessment. Used in concert with activity, enumeration and newly implemented stable isotope methodologies, the field of TWs is certainly moving away from the black-box understanding of the past.
Kela P. Weber. Microbial Community Assessment in Wetlands for Water Pollution Control: Past, Present, and Future Outlook. Water 2016, 8, 503 .
AMA StyleKela P. Weber. Microbial Community Assessment in Wetlands for Water Pollution Control: Past, Present, and Future Outlook. Water. 2016; 8 (11):503.
Chicago/Turabian StyleKela P. Weber. 2016. "Microbial Community Assessment in Wetlands for Water Pollution Control: Past, Present, and Future Outlook." Water 8, no. 11: 503.
Both the presence and diversity of plants are integral to the development and functional abilities of microbial communities within constructed wetlands (CWs). The aim of this study was to assess the impacts of different individual and paired plant species combinations on microbial community function in HSSF mesocosm CWs. Experimental systems were quadruplicated and operated as two mesocosms in series planted with Phragmites australis (X) or Phalaris arundinacea (O), giving four possible sequential combinations (XX, XO, OX, OO). Wastewater was loaded each day into position 1 mesocosm with the outflow entering position 2 mesocosm, and the corresponding position 2 mesocosm outflow representing an overall experimental system effluent. The metabolic function of the interstitial-based microbial communities within each of the 16 mesocosm pairs was assessed at a single time point in the spring (May) based on community-level physiological profiles (CLPPs) gathered using Biolog® EcoPlates. Microbial activity and metabolic richness (number of carbon sources utilised) were found to be higher in position 1 mesocosms compared to position two. Microbial community carbon source utilisation patterns (CSUPs), overall activity and metabolic richness were similar between all mesocosms from position 1—irrespective of plant species. When assessing microbial communities in position 2 of each pairing a greater variety of CSUPs, activities and metabolic richness' could be found suggesting the sequence and choice of plant can alter the microbial community function in the HSSF mesocosms. Of particular interest were the mesocosm/plant species combinations containing Phalaris in the position 2 which led to higher overall microbial activity and richness, distinct carbon source utilisation patterns (CSUPs) and an increased utilisation of specific carbon sources further from the inlet. More specifically the XO pairings (Phragmites-Phalaris) seemed to offer the most promising overall microbial function throughout both positions 1 and 2 in series suggesting plant diversity may help enhance microbial community function, and therefore microbial based water treatment capacity. The findings also suggest that the microbial communities associated with each plant species respond differently to factors such as nutrient availability, and although not yet clearly defined, further highlights the potential for improved or tailored water treatment in CWs through selection of specific plant species and combinations. Broader microbial community function or greater activity did not correlate with improved water treatment efficiency in this study. This may have been due to the relatively low contaminant loads utilised, or the limited amount of data collected. Further study across several seasons or with higher contaminant loads is recommended.
Mark Button; Mariana Rodriguez; Jacques Brisson; Kela P. Weber. Use of two spatially separated plant species alters microbial community function in horizontal subsurface flow constructed wetlands. Ecological Engineering 2016, 92, 18 -27.
AMA StyleMark Button, Mariana Rodriguez, Jacques Brisson, Kela P. Weber. Use of two spatially separated plant species alters microbial community function in horizontal subsurface flow constructed wetlands. Ecological Engineering. 2016; 92 ():18-27.
Chicago/Turabian StyleMark Button; Mariana Rodriguez; Jacques Brisson; Kela P. Weber. 2016. "Use of two spatially separated plant species alters microbial community function in horizontal subsurface flow constructed wetlands." Ecological Engineering 92, no. : 18-27.
Nanoscale zerovalent iron (nZVI) is an emerging technology for the remediation of contaminated sites. However, there are concerns related to the impact of nZVI on in situ microbial communities. In this study, the microbial community composition at a contaminated site was monitored over two years following the injection of nZVI stabilized with carboxymethyl cellulose (nZVI-CMC). Enhanced dechlorination of chlorinated ethenes to nontoxic ethene was observed long after the expected nZVI oxidation. The abundance of Dehalococcoides (Dhc) and vinyl chloride reductase (vcrA) genes, monitored using qPCR, increased by over an order of magnitude in nZVI-CMC-impacted wells. The entire microbial community was tracked using 16S rRNA gene amplicon pyrosequencing. Following nZVI-CMC injection, a clear shift in microbial community was observed, with most notable increases in the dechlorinating genera Dehalococcoides and Dehalogenimonas. This study suggests that coupled abiotic degradation (i.e., from reaction with nZVI) and biotic degradation fueled by CMC led to the long-term degradation of chlorinated ethenes at this field site. Furthermore, nZVI-CMC addition stimulated dehalogenator growth (e.g., Dehalococcoides) and biotic degradation of chlorinated ethenes.
Chris M. D. Kocur; Line Lomheim; Olivia Molenda; Kela P. Weber; LeAnne M. Austrins; Brent Edwin Sleep; Hardiljeet K. Boparai; Elizabeth A. Edwards; Denis O'Carroll. Long-Term Field Study of Microbial Community and Dechlorinating Activity Following Carboxymethyl Cellulose-Stabilized Nanoscale Zero-Valent Iron Injection. Environmental Science & Technology 2016, 50, 7658 -7670.
AMA StyleChris M. D. Kocur, Line Lomheim, Olivia Molenda, Kela P. Weber, LeAnne M. Austrins, Brent Edwin Sleep, Hardiljeet K. Boparai, Elizabeth A. Edwards, Denis O'Carroll. Long-Term Field Study of Microbial Community and Dechlorinating Activity Following Carboxymethyl Cellulose-Stabilized Nanoscale Zero-Valent Iron Injection. Environmental Science & Technology. 2016; 50 (14):7658-7670.
Chicago/Turabian StyleChris M. D. Kocur; Line Lomheim; Olivia Molenda; Kela P. Weber; LeAnne M. Austrins; Brent Edwin Sleep; Hardiljeet K. Boparai; Elizabeth A. Edwards; Denis O'Carroll. 2016. "Long-Term Field Study of Microbial Community and Dechlorinating Activity Following Carboxymethyl Cellulose-Stabilized Nanoscale Zero-Valent Iron Injection." Environmental Science & Technology 50, no. 14: 7658-7670.
In aerated treatment wetlands, oxygen availability is not a limiting factor in sustaining a high level of nitrification in wastewater treatment. In the case of an air blower failure, nitrification would cease, potentially causing adverse effects to the nitrifying bacteria. A field trial was completed investigating nitrification loss when aeration is switched off, and the system recovery rate after the aeration is switched back on. Loss of dissolved oxygen was observed to be more rapid than loss of nitrification. Nitrate was observed in the effluent long after the aeration was switched off (48h+). A complementary modelling study predicted nitrate diffusion out of biofilm over a 48h period. After two weeks of no aeration in the established system, nitrification recovered within two days, whereas nitrification establishment in a new system was previously observed to require 20–45 days. These results suggest that once established resident nitrifying microbial communities are quite robust.
Clodagh Murphy; Amin R. Rajabzadeh; Kela P. Weber; Jaime Nivala; Scott D. Wallace; David J. Cooper. Nitrification cessation and recovery in an aerated saturated vertical subsurface flow treatment wetland: Field studies and microscale biofilm modeling. Bioresource Technology 2016, 209, 125 -132.
AMA StyleClodagh Murphy, Amin R. Rajabzadeh, Kela P. Weber, Jaime Nivala, Scott D. Wallace, David J. Cooper. Nitrification cessation and recovery in an aerated saturated vertical subsurface flow treatment wetland: Field studies and microscale biofilm modeling. Bioresource Technology. 2016; 209 ():125-132.
Chicago/Turabian StyleClodagh Murphy; Amin R. Rajabzadeh; Kela P. Weber; Jaime Nivala; Scott D. Wallace; David J. Cooper. 2016. "Nitrification cessation and recovery in an aerated saturated vertical subsurface flow treatment wetland: Field studies and microscale biofilm modeling." Bioresource Technology 209, no. : 125-132.
Nano-scale zero valent iron (nZVI) has been used at a number of contaminated sites over the last decade. At most of these sites, significant decreases in contaminant concentrations have resulted from the application of nZVI. However, limited work has been completed investigating nZVI field-scale mobility. In this study, a field test was combined with numerical modeling to examine nZVI reactivity along with transport properties in variably saturated soils. The field test consisted of 142 L of carboxymethyle cellulose (CMC) stabilized monometallic nZVI synthesized onsite and injected into a variably saturated zone. Periodic groundwater samples were collected from the injection well, as well as, from two monitoring wells to analyze for chlorinated solvents and other geochemistry indicators. This study showed that CMC stabilized monometallic nZVI was able to decrease tricholorethene (TCE) concentrations in groundwater by more than 99% from the historical TCE concentrations. A three dimensional, three phase, finite difference numerical simulator, (CompSim) was used to further investigate nZVI and polymer transport at the variably saturated site. The model was able to accurately predict the field observed head data without parameter fitting. In addition, the numerical simulator estimated the mass of nZVI delivered to the saturated and unsaturated zones and distinguished the nZVI phase (i.e. aqueous or attached). The simulation results showed that the injected slurry migrated radially outward from the injection well, and therefore nZVI transport was governed by injection velocity and viscosity of the injected solution. A suite of sensitivity analyses was performed to investigate the impact of different injection scenarios (e.g. different volume and injection rate) on nZVI migration. Simulation results showed that injection of a higher nZVI volume delivered more iron particles at a given distance; however, the travel distance was not proportional to the increase in volume. Moreover, simulation results showed that using a 1D transport equation to simulate nZVI migration in the subsurface may overestimate the travel distance. This is because the 1D transport equation assumes a constant velocity while pore water velocity radially decreases from the well during injection. This study suggests that on-site synthesized nZVI particles are mobile in the subsurface and that a numerical simulator can be a valuable tool for optimal design of nZVI field applications.
Ahmed I.A. Chowdhury; Magdalena M. Krol; Christopher M. Kocur; Hardiljeet K. Boparai; Kela P. Weber; Brent E. Sleep; Denis M. O'Carroll. nZVI injection into variably saturated soils: Field and modeling study. Journal of Contaminant Hydrology 2015, 183, 16 -28.
AMA StyleAhmed I.A. Chowdhury, Magdalena M. Krol, Christopher M. Kocur, Hardiljeet K. Boparai, Kela P. Weber, Brent E. Sleep, Denis M. O'Carroll. nZVI injection into variably saturated soils: Field and modeling study. Journal of Contaminant Hydrology. 2015; 183 ():16-28.
Chicago/Turabian StyleAhmed I.A. Chowdhury; Magdalena M. Krol; Christopher M. Kocur; Hardiljeet K. Boparai; Kela P. Weber; Brent E. Sleep; Denis M. O'Carroll. 2015. "nZVI injection into variably saturated soils: Field and modeling study." Journal of Contaminant Hydrology 183, no. : 16-28.