Thermal properties of treatment wetlands operated under freezing conditions.

The use of treatment wetlands (TWs) presents particular challenges in regions with sub-zero winter temperatures, due to reduced biological activity and risk of pipe breakage or clogging due to freezing. We studied the vertical temperature distribution in four pilot-scale TWs exposed to winter temperatures in order to determine the impact of operational system parameters and the role of insulation on heat conservation inside the filtering bed. The overall temperature pattern was similar in all wetlands, with a trend of increasing temperature from the surface toward the bottom during the cold season.

Plant species contribution to bioretention performance under a temperate climate.

Bioretention systems are green infrastructures increasingly used to manage urban stormwater runoff. Plants are an essential component of bioretention, improving water quality and reducing runoff volume and peak flows. However, there is little evidence on how this contribution varies between species, especially in temperate climates with seasonal variations and plant dormancy.

Structure and impact of root-associated fungi in treatment wetland mesocosms.

Root fungal endophytes have been shown to play a positive role in soil phytoremediation by immobilizing or degrading contaminants. In comparison, little is known about their ecological functions and possible role in improving plant performance in treatment wetlands. In a greenhouse study, we compared the structure of fungal communities associated with Phragmites australis roots in treatment wetland mesocosms fed with pre-treated wastewater to mesocosms fed with drinking water.

Stressful, isolated, yet diverse: Green roofs have rich microbiomes that are not dominated by oligotrophic taxa.

Green roofs are unique ecosystems combining two major community assembly filters, namely stress and spatial isolation. As such, they represent an interesting model ecosystem in community ecology. In this study, we characterized the microbiome structure on 19 green roofs and 5 urban parks as a benchmark comparison (i.

Effects of macrophyte species and biochar on the performance of treatment wetlands for the removal of glyphosate from agricultural runoff.

Glyphosate is the most widely used herbicide in the world, and consequently has polluted numerous water bodies through agricultural runoff. Treatment wetlands (TWs) have shown great promise for mitigating such pesticide contamination. The objectives of our study were to determine the effects of adding biochar to subsurface flow TW substrate, and to evaluate the performance of three North American macrophyte species (Phragmites australis subsp.

Design of a zero liquid discharge leachate treatment system using an evapotranspiration willow bed.

While zero liquid discharge (ZLD) wetlands have been successfully used for domestic wastewater treatment, adapting this technology to treat other wastewaters such as leachate could be very attractive for some industries concerned with meeting increasingly stringent environmental regulations. Leachate treatment typically implies large volume of water that are entirely dependent on rainfall and therefore highly variable both throughout the year and between years. Current design guidelines for zero discharge willow systems limit system flexibility because they are based on rough theoretical estimates of evapotranspiration.

Phytochelatin and coumarin enrichment in root exudates of arsenic-treated white lupin.

Soil contamination with toxic metalloids, such as arsenic, can represent a substantial human health and environmental risk. Some plants are thought to tolerate soil toxicity using root exudation, however, the nature of this response to arsenic remains largely unknown. Here, white lupin plants were exposed to arsenic in a semi-hydroponic system and their exudates were profiled using untargeted liquid chromatography-tandem mass spectrometry.

Evaluation of long-term phosphorus uptake by and plants in pilot-scale constructed wetlands.

The aim of this study was to evaluate long-term phosphorus (P) retention in a pilot-scale system made of four horizontal subsurface flow (HSSF) constructed wetlands for wastewater treatment. Each wetland had an area of 4.5 m and was operated for nearly 8 years (2833 days).

Nutrient-assisted phytoremediation of wood preservative-contaminated technosols with co-planting of Salix interior and Festuca arundinacea.

The remediation of wood preservative-contaminated sites is an important issue due to the carcinogenic nature of some contaminants derived from wood preservatives (e.g., Cr, arsenate, and pentachlorophenol).

Bioaugmentation of treatment wetlands - A review.

Bioaugmentation in the form of artificial mycorrhization of plant roots and bacterial inoculation has been successfully implemented in several fields including soil remediation or activated sludge treatment. Likewise, bioaugmentation seems a promising approach to improve the functioning of treatment wetlands, considering that natural mycorrhization has been detected in treatment wetlands and that bacteria are the main driver of contaminant degradation processes. However, to date, full scale implementation seems to be rare.

Macrophyte Potential to Treat Leachate Contaminated with Wood Preservatives: Plant Tolerance and Bioaccumulation Capacity.

Pentachlorophenol and chromated copper arsenate (CCA) have been used worldwide as wood preservatives, but these compounds can toxify ecosystems when they leach into the soil and water. This study aimed to evaluate the capacity of four treatment wetland macrophytes, , , and two subspecies of , to tolerate and treat leachates containing wood preservatives. The experiment was conducted using 96 plant pots in 12 tanks filled with three leachate concentrations compared to uncontaminated water.

Co-planting of and for phytoremediation of trace elements from wood preservative contaminated soil.

Phytoextraction potential of a co-planting system was evaluated using a shrub and an herbaceous species and compared with monocultures. A greenhouse experiment with and grown in combination or alone was conducted for 120 days in soil either uncontaminated or contaminated with wood preservatives containing mixed chromated copper arsenate and pentachlorophenol (PCP). The results showed that the plant species produced similar amounts of dry biomass per pot in monoculture and co-planting, whether growing in contaminated or uncontaminated soil.

Plant diversity effect on water quality in wetlands: a meta-analysis based on experimental systems.

The ecological literature reports little empirical evidence from biodiversity-ecosystem functioning (BEF) experiments in wetland systems, even though wetlands are widely known for their water filtering capacity. Experiments comparing the effect of plant monocultures and mixtures on water quality to improve pollutant removal efficiency in treatment wetlands share the characteristics of classical BEF experiments, and so could provide insights for wetland management. To add to our understanding of BEF relationships in wetlands, we evaluated plant diversity effects on water purification through a meta-analysis of freshwater experimental wetlands comparing monocultures to mixtures.

Establishment and potential use of woody species in treatment wetlands.

Plant species selection is an important criterion for improving treatment wetland performance. The aim of this work was to evaluate removal efficiency and potential uses of woody species in treatment wetlands during the establishment year. Plant development, removal efficiency and evapotranspiration rate of five woody species () and four herbaceous taxa typically used in treatment wetlands () were compared in a mesocosm-scale study during one growing season.

Willows for environmental projects: A literature review of results on evapotranspiration rate and its driving factors across the genus Salix.

Willows are increasingly used for a wide range of environmental projects, including biomass production, leachate treatment, riparian buffers and treatment wetlands. Evapotranspiration (ET), assumed to be high for most willow species used in environmental projects, affects hydrological cycles and is of key interest for project managers working with willows. Here, we present a comprehensive review of ET rates provided in the literature for the genus Salix.

Screening Sensitivity According to Breast Cancer Location.

Purpose: To examine the relation between breast cancer location and screening mammogram sensitivity, and assess whether this association is modified by body mass index (BMI) or breast density.

Methods: This study is based on all interval cancers (n = 481) and a random sample of screen-detected cancers (n = 481) diagnosed in Quebec Breast Cancer Screening Program participants in 2007. Film-screening mammograms, diagnostic mammograms, and ultrasound reports (when available) were requested for these cases.

Mammography Clinical Image Quality and the False Positive Rate in a Canadian Breast Cancer Screening Program.

Purpose: The study sought to determine if mammography quality is associated with the false positive (FP) rate in the Quebec breast cancer screening program in 2004 and 2005.

Methods: Mammography quality of a random sample of screen-film mammograms was evaluated by an expert radiologist following the criteria of the Canadian Association of Radiologists. For each screening examination, scores ranging from 1 (poor quality) to 5 (excellent quality) were attributed for positioning, compression, contrast, exposure level, sharpness, and artifacts.

Plant growth and nutrient uptake in treatment wetlands for water with low pollutant concentration.

The objective of this study was to determine how macrophytes commonly used in treatment wetlands (TWs) respond to water with low pollutant concentration. We measured pollutant removal efficiency and compared growth and nutrient uptake of five macrophytes in demonstration scale units (volume >40 m) irrigated by water with pollutant concentrations representative of average urban stormwater quality. All species showed a strong productivity gradient along the beds, starting with high biomass - high density near the inlet, then decreasing progressively with distance.

Clinical Image Quality and Sensitivity in an Organized Mammography Screening Program.

Purpose: The study sought to examine the association between clinical image quality of mammograms and screening sensitivity.

Methods: Four radiologists evaluated the clinical image quality of 374 invasive screen-detected cancers and 356 invasive interval breast cancers for which quality evaluation of screening mammograms could be assessed from cancers diagnosed among participants in the Quebec Breast Cancer Screening Program in 2007. Quality evaluation was based on the Canadian Association of Radiologists accreditation criteria, which are similar to those of the American College of Radiology.

Complementarity of three distinctive phytoremediation crops for multiple-trace element contaminated soil.

Trace element (TE) contaminated land represents an important risk to the environment and to human health worldwide. These soils usually contain a variety of TEs which can be a challenge for plant-based remediation options. As individual plant species often possess a limited range of TE remediation abilities, functional complementarity principles could be of value for remediation of soil contaminated by multiple TEs using assemblages of species.

Standard Period Life Table Used to Compute the Life Expectancy of Diseased Subpopulations: More Confusing Than Helpful.

Life expectancy (LE) based on a period life table (PLT) traditionally serves as a general population summary metric. It is, however, becoming more frequently reported for chronically afflicted subpopulations. In general populations, there is always an obvious real cohort sharing the hypothetical PLT cohort characteristics, and the LE estimate is intuitively understood as that real cohort mean survival time, assuming constancy of death risks.

A Randomized Double-Blind Placebo-Controlled Trial of the Effect of Vitamin D Supplementation on Breast Density in Premenopausal Women.

This double-blind, placebo-controlled parallel group trial assessed whether oral supplementation with 1,000, 2,000, or 3,000 IU/day vitamin D over one year reduces percent mammographic breast density in premenopausal women. The trial was conducted between October 2012 and June 2015, among premenopausal female volunteers from Quebec City (Quebec, Canada). Women were randomized with ratio 1:1:1:1 to one of four study arms (1,000, 2,000, or 3,000 IU/day vitamin D or placebo).