Effects Of Deicing Salts Research Articles

Using wood chips for the protection of plants and soil from the harmful effects of road salt

In this study, the use of a new system made of natural wood absorbers (Salix viminalis) is proposed as a tool to protect plants, groundwater and soil from the adverse effects of de-icing salt. The toxic effects of road de-icing salt on soils, groundwater and plant growth have concerned environmental scientists, especially ecologists, for decades and have already been the subject of many studies. In terms of both time and cost, sodium chloride is widely regarded as the most effective chemical for de-icing roads and pavements. The protection of roadside plants is mainly achieved by using physical barriers with a limited capacity to retain road salt. Willow chips were packed into three systems: separated micro-columns, separated micro-columns with retention cups, and a monolayer column. Each system eliminated some of the salt from a brine solution such that only low-salinity water penetrated into the soil. The efficiency of road salt uptake varied from 31–95% depending on the system. The efficiency of the system was determined based on the salt content measured in the absorber collected after winter. Soil contamination by de-icing salt and the migration of different ions in groundwater were beyond the scope of this study.

Deicing Salt Pollution Affects the Foliar Traits and Arthropods' Biodiversity of Lime Trees in Riga's Street Greeneries

Street greeneries and other green spaces within the urban matrix can potentially reduce air pollution and increase urban biodiversity. Yet, these services can be negatively affected by anthropogenic stress factors. In the boreo-nemoral zone, large amounts of salts are spread each year for deicing the pavement. To address the effect of deicing salt on street lines of lime trees and how this cascades up to influence the surrounding arthropod biodiversity, we compared heavily salt-polluted and less polluted sites in the city of Riga, Latvia. We analyzed the impairment of foliar functions and development of aphids’ colonies using a common garden experiment. We found marked variation in the soil physico-chemical properties in polluted versus unpolluted sites. The overall abundance of arthropods, including that of the lime tree aphid specialist, was decreased and, as a consequence, less biotic injury was observed in foliage. The exposure to increased salt levels in the soil caused functional as well as structural injuries within foliage and slowed down the development of aphid colonies. The effects of de-icing salts thus appeared to cascade up through the trophic chain and to negatively affect not only the trees but also the associated arthropod biota. These findings point at the necessity of a wider screening of plant species and cultivars that not only better tolerate anthropogenic stress but also promote the biodiversity in cities.

融雪剂对Cd在土壤中吸附规律及动力学影响

融雪剂对Cd在土壤中吸附规律及动力学影响

Effects of De-icing Salts on the Respiration of the Microorganisms of Activated Sludge

Winter road maintenance is particularly ensured using the application of chemicals on roads. Especially in urbanised areas, the solution of water with de-icing salts is discharged into sewer system transporting this water to wastewater treatment plant, where it can cause lot of problems. Beside the corrosive effects of salt on the materials used for sewer system and technological equipment of wastewater treatment plant, salt concentration affects the efficiency of biological wastewater treatment. The analyses performed with activated sludge from wastewater treatment plant showed that commonly used de-icing salts (NaCl, MgCl2, CaCl2) profoundly affected the respiratory activity of its microorganisms. Increasing concentrations of chloride in the influent of the wastewater treatment plant caused a progressive decrease in respiratory activity and a progressive prolongation of the acclimation period of the microbial community. The extent of the increase in the acclimation period was dependent on the examined road salt.

Spatio-temporal analysis of remotely-sensed forest mortality associated with road de-icing salts

Forest mortality along highways has long been a concern in areas where de-icing compounds are applied during winter. This study combined the spatial advantage of high-resolution remote sensing imagery and the temporal advantage of long-term archival imagery to quantify forest mortality and to detect the subtle and chronic effects of road de-icing salts for a large mountain watershed in the Sierra Nevada Mountains, USA. IKONOS-derived mortality was used in a fine-scale spatial analysis to assess road proximity and roadside topography effects on forest mortality and to compare two potential mechanisms of de-icing salt damage, i.e. aerial deposition and soil uptake. These mechanisms were modeled using spatial proxy variables that were constructed from LiDAR topographical data. The analysis revealed a clear trend of increasing mortality with increasing potential for aerial deposition of de-icing salt onto tree crowns, mainly occurring within 10m from roads. The effect of soil uptake of salt was weaker than that of aerial deposition but had a broader potential effect zone that extended to at least 100m from roads. Landsat TM-derived mortality from 1989 to 2010 provided a long-term time series that indicated both immediate and lagged effects of salt application on forest mortality. Immediate effects of de-icing salt were only distinct in wet years when salt application and spray generation by passing traffic and snow plowing were likely high and other damaging factors, such as bark beetles or drought mortality, were likely weak. A strong and consistent one-year lag in the effect of salt application on incidence of mortality suggested that longer-term impacts of de-icing salt on forest health likely involved more complex pathways than simply aerial deposition. Our multi-scale remote sensing approach provided convincing evidence that de-icing salt was a significant factor for roadside forest mortality and allows for efficient future monitoring at the large-watershed scale.

Effect of de-icing salts on the corrosion performance of galvanized steel in sulphate contaminated soil

Failure of mechanically-stabilized earth (MSE) walls attributed to the corrosion of galvanized steel in soil has raised concern on the use of an appropriate type of the de-icing salt for the maintenance of the roads in the winter. This work presents the effect of commonly used de-icing salts such as sodium chloride, magnesium chloride, calcium chloride, and potassium acetate on the corrosion performance of the galvanized steel in sulphate contaminated soil. To achieve this goal, different electrochemical testing methods such as potentiodynamic polarization, Linear Polarization Resistance, and electrical impedance spectroscopy were used to determine the corrosion rate of galvanized steel reinforcement in sodium sulphate containing solution. Results showed that the presence of sulphate in the soil significantly increased the corrosion rates and, thus, it is important to consider the effect of sulphate in determining the type of de-icing salt. In sulphate-free solution, potassium acetate appeared to be the best option; while in the presence of sulphate, MgCl2 and CaCl2 had the lowest corrosion rate.

11. Aggregates in bituminous bound construction materials

Both natural and artificial aggregates of coarse and fine sizes are employed in bituminous mixtures for highway and airfield pavements (Fig. 10.1) and in hydraulic and building appHcations (The Shell Bitumen Handbook 1990). The emphasis in this chapter is upon the use of bituminous materials in pavement construction. The same factors affecting mix density, strength, stiffness and adhesion, apply in hydraulic applications as in pavement construction. However, in the former, greater attention is paid to such properties as permeabiHty (which may be required to be high or low depending on the particular application), resistance to flow on steep slopes and, where relevant, to wave impact (Hills & McAughtry, 1986). Polishing resistance characteristics of aggregates clearly have no importance in hydraulic applications but, in building construction, mastic asphalts used in bridge decks and in decks and ramps of multi-storey car parks require a high skid resistance. Chief among the requirements of mastic asphalt for bridge decks, roofing and car parks is impermeability in order to protect the underlying concrete construction from water and frost attack and from the effect of de-icing salts and other chemicals (Mastic Asphalt Conferences 1989). The major factor in these applications is the mix design, involving use of a high bitumen content in accord with the high content of fine aggregate and filler in the aggregate grading. It should be noted that, at the time of going to press, several relevant developments were taking place with respect to the specification of aggregates for bituminous

Effects of de-icing salt on roadside grasses and herbs

The harmful effect of de-icing salt on roadside herbs and grasses depends on the sensitivity of the plant species. Seedlings are more sensitive to salt than adult plants. At a low temperature (5°C) the plants were not affected by high salt concentrations. In winter with short frost periods (1–3 weeks) the harmful effect of de-icing salt on grasses and herbs will therefore be hampered by the low physiological activity of the plants.

Effects of de-icing salt on soil enzyme activity

Effects of de-icing salt on dehydrogenase, urease, alkalihephosphatase and arylsulfatase activity ofOL andAh-horizons of a moder and a mull soil were investigated using a field experiment. Additions of 2.5 kg m−2 and 5.0 kg m−2 of de-icing salt reduced activities of most enzymes within four weeks. Eleven months after salt addition there was nearly no reduction of enzyme activity to be measured on salt treated soils. The percentage of reduced enzyme activity was generally higher in the moder soil. It was concluded that reductions of enzyme activity were due to decreases of microbial activity and not to inactivation of enzymes.

DE-ICING SALT AND CROWN DAMAGE TO LONDON PLANE

Summary During the post-war period, crown dieback has occurred periodically in London plane planted in London and other British cities. Most affected trees are very close to roadsides but some damage has been recorded in parkland trees more than 45 m from roads. Recent investigations strongly suggest that much of the damage can be attributed to the effect of de-icing salt applied to roads during severe winters. The main symptom of this disorder is the death of foliage shortly after flushing, with some branches typically being more affected than others. Later in the summer remaining leaves may develop marginal and interveinal scorching. Chloride levels in leaves from affected trees are between 1 and 3 per cent of the dry weight, well above the 0.1–0.3 per cent found in unaffected trees. In certain years quite severe disease in plane can be caused by the anthracnose fungus, Gnomonia platani, which can infect buds, shoots and leaves. It seems likely that this fungus could have been responsible for the damage...

Perspectives of reducing the deleterious effect of de-icing salt upon vegetation

The protective effect of a nutrient solution upon young forest plants, seriously stressed by de-icing salt (NaCl) were investigated. The results show, that the adsorbed salt ions in the soil are already exchanged at low concentrations (2 bars), whilst plant survival and growth showed only at higher concentrations (10 bars) a significant optimum.

Effects of De-Icing Salt on Ground Water Characteristics

The effect of "road salt" on the characteristics of Massachusetts drinking water supplies has been significant and cumulative rather than transient or seasonal. De-icing salt is essentially all sodium chloride. Calcium chloride accounted for only three percent of the total salt used. However, hardness content, as well as sodium ion concentration, has increased greatly in ground waters in the past decade. The changing composition of our water supplies has agricultural, economic, and public health implications. This study attempts to quantify the stoichiometry of these changes in concentration, which are in part due to an ion-exchange mechanism in the soil.

The Effects of De-Icing Salt on Roadside Verges. I. Soil and Plant Analysis

The Effects of De-Icing Salt on Roadside Verges. I. Soil and Plant Analysis