Infiltration of de-icing road salts in aquifers: the Trois-Rivières-Ouest case, Quebec, Canada

1989 ◽  
Vol 26 (11) ◽  
pp. 2186-2193 ◽  
Author(s):  
Jacques Locat ◽  
Pierre Gélinas
Keyword(s):  
Unsaturated Zone ◽  
Chloride Concentration ◽  
Late Summer ◽  
Linear Source ◽  
Pumping Wells ◽  
Road Salts ◽  
Hydrogeological Investigation ◽  
Spring Snowmelt ◽  
Chloride Concentrations

The results of an extensive hydrogeological investigation of the effects of de-icing road salts on Highway 55 near Trois-Rivières-Ouest indicate that a salt lens with chloride concentrations exceeding 800 mg/L exists below the highway. Maximum chloride concentration at the nearby pumping wells, not exceeding 140 mg/L, is reached only in late summer, whereas the maximum chloride infiltration follows the spring snowmelt. About 1 year's worth of road salts is retained in the unsaturated zone. The salt lens, in the upper part of the aquifer beneath the highway, has developed to a thickness of 8 m and a width of 400 m and constitutes a linear source of salts for the aquifer. The shape of this lens is distorted by the action of the pumping wells, and the lens is partly depleted by the end of the summer. Because of the particular characteristics of the aquifer at the site studied and the exploitation methods, no long-term threat to the water quality is foreseen.

scholarly journals Preliminary Results from Unsaturated Zone Studies in Unconfined Unconsolidated Coastal Aquifers

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 642
Author(s):  
Efthymia Zavridou ◽  
Konstantinos Markantonis ◽  
Ioannis Argyrokastritis ◽  
Konstantinos Voudouris ◽  
Andreas Kallioras
Keyword(s):  
Unsaturated Zone ◽  
Chloride Concentration ◽  
Soil Samples ◽  
Chemical Analyses ◽  
Environmental Tracers ◽  
Soluble Salts ◽  
Vacuum Filtration ◽  
Naturally Occurring ◽  
Hydrologic Conditions ◽  
Chloride Concentrations

Chloride concentration and salinity tend to vary spatially in depth within the unsaturated zone, according to the local hydrologic conditions; and therefore are widely used as naturally occurring environmental tracers. In this study, undisturbed material from the unsaturated zone was collected at regular intervals of 50 cm down to a maximum depth of 300 cm in 17 different locations. Vacuum filtration has been used for extraction of soil water from 75 soil samples, and chemical analyses showed that the chloride concentrations in soils range from 0.4 to 79 meq/L indicating the existence of soluble salts, also verified by elevated electrical conductivity values.

The Expression of Surface Chloride Concentration in Ecological Concrete and Service Life Prediction

2011 ◽  
Vol 368-373 ◽  
pp. 2204-2210 ◽  
Author(s):  
Si Feng Liu
Keyword(s):  
Fly Ash ◽  
Service Life ◽  
Life Prediction ◽  
Chloride Concentration ◽  
Total Chloride ◽  
One Dimensional ◽  
Dimensional Diffusion ◽  
Diffusion Depth ◽  
Chloride Concentrations

The total chloride concentrations of concrete with 0.51 of water to cementitous from three contents of Fly ash, GGBS, two kinds of corrosion solution for one dimensional diffusion at different diffusion depth and time were measured by chemical titration. The influence of Fly ash and GGBS content on total chloride concentration and the surface chloride concentration were analyzed. The expressions of the surface chloride concentration were discussed in terms of the experimental results related with content of Fly ash, GGBS and solution. The numerical analysis results indicated that the expression of the surface chloride concentration has a significant impact on the long-term service life of concrete in chloride environments.

Road Salt Application in Highland Creek Watershed, Toronto, Ontario - Chloride Mass Balance

2010 ◽  
Vol 45 (4) ◽  
pp. 451-461 ◽  
Author(s):  
Nandana Perera ◽  
Bahram Gharabaghi ◽  
Peter Noehammer ◽  
Bruce Kilgour
Keyword(s):  
Mass Balance ◽  
Management Practices ◽  
Chloride Concentration ◽  
Aquatic Organisms ◽  
Terrestrial Ecosystems ◽  
Road Salt ◽  
Winter Period ◽  
Chloride Mass Balance ◽  
Creek Watershed ◽  
Chloride Concentrations

Abstract Occurrence of increasing chloride concentrations in urban streams of cold climates, mainly due to road salt application, has raised concerns on its adverse effects on aquatic and terrestrial ecosystems. Therefore, there is a need for a better understanding of processes associated with road salt application and subsequent discharge into the environment in order to develop management practices to minimize detrimental effects of chlorides. The chloride mass analysis for the Highland Creek watershed based on four years of hourly monitoring data indicates that approximately 60% of the chlorides applied on the watershed enter streams prior to subsequent salting period, 85% of which occurs during the period between November and March. Contribution of private de-icing operations on chloride mass input within Highland Creek watershed was estimated to be approximately 38%, indicating its significance in overall chloride mass balance. Salt application rates, as well as chloride output in the streams, vary spatially based on land use, influencing chloride concentrations in surface waters. The estimated groundwater chloride concentration of 275 mg/L indicates that some aquatic organisms in Highland Creek would potentially be at risk even outside the winter period under dry weather flow conditions.

Column Study on the Effect of Nitrate and Chloride on TCE Removal by Granular Iron

2011 ◽  
Vol 356-360 ◽  
pp. 1642-1646
Author(s):  
Xue Qiang Zhu ◽  
Bao Ping Han ◽  
Guo Jun Wu ◽  
Xiao Qing Zhang
Keyword(s):  
Pitting Corrosion ◽  
Nitrate Concentration ◽  
Chloride Concentration ◽  
Inorganic Anions ◽  
Dual Effect ◽  
Column Study ◽  
Granular Iron ◽  
High Chloride ◽  
Chloride Concentrations

The effects of individual inorganic anions (nitrate and chloride) on the reactivity of granular iron were investigated using plexiglass columns packed with granular iron. The results show that TCE removal decreases apparently with increasing nitrate concentration due to competition for reactive sites. Chloride exhibits dual-effect on the TCE removal by Fe0. In the studied condition, the TCE dechlorination is enhanced at the low chloride concentration due to pitting corrosion and is dampened at the high chloride concentrations such as 59.98 and 110.45 mg/L as Cl-.

scholarly journals Application of Novel Machine Learning Techniques for Predicting the Surface Chloride Concentration in Concrete Containing Waste Material

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2297
Author(s):  
Ayaz Ahmad ◽  
Furqan Farooq ◽  
Krzysztof Adam Ostrowski ◽  
Klaudia Śliwa-Wieczorek ◽  
Slawomir Czarnecki
Keyword(s):  
Machine Learning ◽  
Mean Square Error ◽  
Gene Expression Programming ◽  
Chloride Concentration ◽  
Absolute Error ◽  
Chloride Ions ◽  
Machine Learning Techniques ◽  
Extensive Literature ◽  
Mean Square ◽  
Chloride Concentrations

Structures located on the coast are subjected to the long-term influence of chloride ions, which cause the corrosion of steel reinforcements in concrete elements. This corrosion severely affects the performance of the elements and may shorten the lifespan of an entire structure. Even though experimental activities in laboratories might be a solution, they may also be problematic due to time and costs. Thus, the application of individual machine learning (ML) techniques has been investigated to predict surface chloride concentrations (Cc) in marine structures. For this purpose, the values of Cc in tidal, splash, and submerged zones were collected from an extensive literature survey and incorporated into the article. Gene expression programming (GEP), the decision tree (DT), and an artificial neural network (ANN) were used to predict the surface chloride concentrations, and the most accurate algorithm was then selected. The GEP model was the most accurate when compared to ANN and DT, which was confirmed by the high accuracy level of the K-fold cross-validation and linear correlation coefficient (R2), mean absolute error (MAE), mean square error (MSE), and root mean square error (RMSE) parameters. As is shown in the article, the proposed method is an effective and accurate way to predict the surface chloride concentration without the inconveniences of laboratory tests.

Letter to the Editor

PEDIATRICS ◽  
1969 ◽  
Vol 43 (5) ◽  
pp. 905-906
Author(s):  
Aubrey Milunsky
Keyword(s):  
Cystic Fibrosis ◽  
Bone Marrow ◽  
Clinical Presentation ◽  
Pancreatic Insufficiency ◽  
Chloride Concentration ◽  
Letter To The Editor ◽  
Patient Reported ◽  
Sweat Sample ◽  
Chloride Concentrations

The patient reported in the foregoing letter is of particular interest in view of the recent observations on patients with tnisomy 21 and cystic fibrosis. The multiple possibilities that could explain the clinical presentation have no doubt been considered by the authors. However, the description of "hypoplastic thrombocytopenia" and later pancytopenia in this patient, associated with pancreatic insufficiency, leads to the serious consideration of Shwachman's syndrome (pancreatic insufficiency and bone marrow dysfunction). The wide discrepancy between the sodium and chloride concentrations in the sweat reported in their letter indicates that evaporation of water may have occurred from the sweat sample, leading to an apparently higher sodium and chloride concentration.

scholarly journals Changes in historical typhoid transmission across 16 U.S. cities, 1889-1931: Quantifying the impact of investments in water and sewer infrastructures

2019 ◽  
Author(s):  
Maile T. Phillips ◽  
Katharine A. Owers ◽  
Bryan T. Grenfell ◽  
Virginia E. Pitzer
Keyword(s):  
Late Summer ◽  
Water Source ◽  
Developed Countries ◽  
The United States ◽  
Water And Sanitation ◽  
Sewer Systems ◽  
Early Fall ◽  
Sanitation Systems ◽  
The Impact

ABSTRACTBackgroundInvestments in water and sanitation systems are believed to have led to the decline in typhoid fever in developed countries, such that most cases now occur in regions lacking adequate clean water and sanitation. Exploring seasonal and long-term patterns in historical typhoid mortality in the United States can offer deeper understanding of disease drivers.MethodsWe fit modified Time-series Susceptible-Infectious-Recovered models to city-level weekly mortality counts to estimate seasonal and long-term typhoid transmission. We examined seasonal transmission separately by city and aggregated by water source. We fit regression models to measure associations between long-term transmission and financial investments in water and sewer systems.ResultsTyphoid transmission peaked in late summer/early fall. Seasonality varied by water source, with the greatest variation occurring in cities with reservoirs. Historical $1 per capita ($25.80 in 2017) investments in construction and operation of water and sewer systems were associated with 8-53% decreases in typhoid transmission, while $1 increases in total value or debt accrued to maintain them were associated with 4-7% decreases.ConclusionOur findings aid in the understanding of typhoid transmission dynamics and potential impacts of water and sanitation improvements, and can inform cost-effectiveness analyses of interventions to reduce the typhoid burden.

PROPERTIES OF A SET OF INTERNAL RECEPTORS IN THE MEDICINAL LEECH: THE NEPHRIDIAL NERVE CELLS MONITOR EXTRACELLULAR CHLORIDE CONCENTRATION

1989 ◽  
Vol 143 (1) ◽  
pp. 115-132 ◽  
Author(s):  
ANGELA WENNING
Keyword(s):  
Ion Homeostasis ◽  
Chloride Concentration ◽  
Dendritic Tree ◽  
Medicinal Leech ◽  
Nerve Cells ◽  
Control Factor ◽  
Intracellular Recordings ◽  
Extracellular Recordings ◽  
Cl Conductance

In the leech, Hirudo medicinalis, the functional properties of the peripheral nephridial nerve cells (NNCs) were investigated using long-term extracellular recordings from both intact and isolated preparations The NNCs respond selectively to changes in external Cl− concentration: their electrical activity is highest in fluid containing normal (i.e. low) extracellular [Cl−]. Their sensitivity to Cl− is confined to the dendritic tree. Extracellular [Cl−] is a control factor for ion homeostasis. It increases drastically after a blood meal, and after the animal has left the water or invaded brackish water. The NNCs continuously monitor the extracellular Cl− concentration: their burst rate changes, without adapting, by a factor of 4 in the physiological range between 40 and 90 mmoll−1. Intracellular recordings from the NNC in isolated nephridial complexes suggest that a high Cl− conductance in combination with active transport of Cl− could be responsible for the observed Cl− sensitivitys

Irrigation and Rootstocks to Manage Northern Root-Knot Nematode During Wine Grape Vineyard Establishment

2021 ◽  
Author(s):  
Katherine East ◽  
Inga Zasada ◽  
R. Paul Schreiner ◽  
Michelle Marie Moyer
Keyword(s):  
Late Summer ◽  
Field Trials ◽  
Meloidogyne Hapla ◽  
Root Knot Nematode ◽  
Cultural Management ◽  
Host Status ◽  
Management Approaches ◽  
Eastern Washington ◽  
Establishment Phase

Vineyard replanting in Washington state can be negatively impacted by the plant-parasitic nematode Meloidogyne hapla. Chemically-focused nematode management programs do not offer long-term suppression, however, this may be achieved through the adoption of cultural approaches such as rootstocks and irrigation. Nematode-resistant rootstocks are used extensively in other regions, but many have not been tested against M. hapla. Vineyards in eastern Washington are irrigated, so manipulating available soil water may also impact nematode development. In 2017, two field trials were established in eastern Washington to evaluate the effects of: 1) late-summer water limitation on M. hapla population development, and 2) host status of 1103 Paulsen, 3309 Couderc and Matador rootstocks for M. hapla. The efficacy of these cultural management approaches was evaluated under three initial M. hapla densities (0, 50, and 250 M. hapla J2 per 250 g soil) in both trials. Reducing irrigation to manage M. hapla infestation of grape roots was ineffective and may cause harm to the vines by inducing too much water stress. Conversely, rootstocks effectively reduced population densities of M. hapla. Overall, rootstocks show the most promise as a cultural tool to manage M. hapla during the establishment phase in Washington vineyards.

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