Recycled Polyethylene Modified Asphalt Binders and Mixtures: Performance Characteristics and Environmental Impact

This study addresses the effects of recycled polyethylene (RPE) on the performances of both asphalt binders and asphalt mixtures. Whether using RPE in an asphalt mixture might leach harmful chemicals into rainwater or melted snow was also determined. Two processes, wet and dry, were used to formulate the RPE modified asphalt binders and mixtures. In the wet process, RPE was added to asphalt binder. In the dry process, it was added to heated aggregates. RPE from two sources and PG 64-22 virgin asphalt binders from two sources were used in this study. In conclusion, RPE improved the rutting resistance of the asphalt binders and asphalt mixtures. However, it had adverse effects on their resistance to intermediate-temperature and non-load associated cracking. The dry process could produce a mixture with a higher RPE dosage compared with the wet process using one virgin asphalt binder but not the other; thus, the virgin asphalt binder source was a significant factor for the dry process. Based on an embryotoxicity test, it was found that RPE can be used by the asphalt paving industry without creating any significant environmental risks.

Ultraviolet germicidal irradiation of melted snow and ice samples: inactivation of microorganisms and effects on insoluble microparticles

The long-term refrigerated storage of melted snow and/or ice samples for analyses of insoluble microparticles (hereafter, microparticles) may be limited by increases in the biological particle concentration caused by microbial growth after ~1–2 weeks. In this study, we examined an ultraviolet (UV) disinfection method for the storage of melted snow and/or ice samples and determined the effects of this method on microparticles. Surface snow obtained from Glacier No. 31 in the Suntar-Khayata Range, eastern Siberia, Russia was divided into two portions for UV treatment and untreated controls. Microparticle concentrations and size distributions (in the range of 0.52–12.0 μm) in the samples were measured using a Coulter counter. Whereas the microparticle concentration in untreated samples increased, no obvious increase was observed over 53 d in the samples subjected to UV treatment. Microbial growth was detected in only untreated samples using a viable particle counter. In addition, the original microparticle concentrations and size distributions were unaffected by UV treatment. Our results demonstrated that the microparticle size distribution in untreated melted water samples reflects the growth, decomposition and succession of microorganisms over time and further indicate that UV irradiation is effective for long-term storage for microparticle analysis.

GROUND AND SATELLITE MONITORING OF POLLUTION PROCESSES ISKITIM-LINEVSK INDUSTRIAL ZONE

The results of a numerical analysis of atmospheric pollution in the vicinity of the industrial site of the Chernorechensky cement plant (CCP) and the territory of Iskitim are presented. The research material was the results of sampling melted snow for 2019-20. The snow index (NDSI), calculated from high-resolution images from the Landsat and Sentinel satellites, was used as satellite data. Statistical relationships between ground-based and satellite observations are given. The general dynamics of changes in the impurity concentration in the snow and NDSI values are revealed. The concentration is calculated on the basis of low-parameter reconstruction models using ground-based measurements. For calculations and visualization, the means of the geographic information system, which was developed earlier, were used. These studies represent the basis for the development of a methodology for a comprehensive analysis of the process of atmospheric pollution using ground-based and satellite observations.

Examination of ultraviolet germicidal radiation for inactivating microorganisms in melted snow and ice samples

<p>The storage of melted snow and/or ice samples from snow pits and ice cores in a refrigerator for long durations may be limited by an increase in particle concentration caused by microbial growth after approximately 1–2 weeks. In this study, we examined an ultraviolet (UV) disinfection method for the storage of melted snow and/or ice samples. Surface snow obtained from Glacier No. 31 in the Suntar-Khayata Range, eastern Siberia, Russia was divided into two portions for UV treatment and untreated controls. Particle concentrations in the samples were measured using a Coulter counter (Multisizer 4e; Beckman Coulter, USA). Whereas the particle concentration in untreated samples increased, no obvious increase was observed over 53 days in the samples subjected to UV treatment. In addition, the original particle concentrations were unaffected by UV treatment. These findings indicate that the antimicrobial effect of UV radiation is effective for long-term sample storage of melted water samples. A detailed analysis of the particle size distribution for untreated samples indicated that particles of 0.7–1.2 µm appeared within the first 7–14 days. Measurements using a viable particle counter (XL-10BT2 and XL-28A1; RION Co. Ltd., Japan) confirmed that these were biological particles, suggesting that microbial growth occurs during this period. Subsequently, the particles shifted to a smaller size and a higher concentration, suggesting that the decomposition of microorganisms occurred in the water samples. Therefore, the size distribution of particles in untreated samples reflected the growth and decomposition of microorganisms over time.</p>

Geochemical composition of Holocene and Late Pleistocene ice wedges in the yedoma of Stanchikovsky Yar and near the Chersky town, Northern Yakutia

The subject of this research is the Late Pleistocene and Holocene ice wedges exposed near Chersky settlement, lower Kolyma River, and in the yedoma strata of the Stanchikovsky Yar on the Maly Anyuy River. In the yedoma of the Stanchikovsky Yar, multi-tiered syngenetic ice wedges were exposed at different levels – from 10 to 35 m above river level. Ice wedge in the lower tier was sampled in detail. In the yedoma strata near Chersky relatively small fragments of ice wedges up to 1.5 m wide and up to 2 m high were exposed. 1.5-2 km from Chersky within the lacusrtine-paludal depression Holocene ice wedges were exposed. Ice wedges in these three sections was sampled to clarify the geochemical conditions of their formation. It is shown that concentration of Na+, K+, Mg2+, Cl- and SO42- in Holocene and Late Pleistocene ice wedges is very low and mean values do not exceed 5 mg/L. The highest values were obtained for Ca2+, which corresponds to the predominance of this ion in the modern snow of Yakutia and indicates that ice wedges were formed mainly from melted snow. Rather high values of NO3-, reaching 14-27 mg/L, are quite likely due to the swampy environment within polygonal landscapes, where organic matter of both plant and animal origin is decomposed. For comparison, in the water of the Kolyma and Maly Anyu rivers, concentration of nitrates is quite low and does not exceed 0.3 mg/L.

Winter Maintenance of Permeable Interlocking Concrete Pavement: Evaluating Opportunities to Reduce Road Salt Pollution and Improve Winter Safety

Permeable interlocking concrete pavement (PICP) is a type of permeable pavement system that uses the joint spaces between pavers to drain water from the surface into an aggregate base and subbase layer below. Because of its ability to rapidly drain surface water, PICP has the potential to reduce the amount of ice formed on the surface during winter conditions compared with traditional impervious pavements. As a result, PICP may reduce the amount of road salt needed for de-icing paved surfaces and may also reduce the risk of pedestrian slipping and vehicle skidding throughout the winter. This study evaluates the performance of an outdoor PICP and asphalt test pad over two winter seasons in Vaughan, Ontario, Canada, by assessing differences in surface conditions, surface friction, and surface temperatures. The results of this study indicate that PICP provides equivalent or higher levels of safety compared with asphalt when treated with de-icing products at medium (0.049 kg/m2) or low (0.024 kg/m2) application rates. Re-freezing of melted snow and ice after sunset was observed on the asphalt surface creating black ice, but not on the PICP cells. Consequently, compared with asphalt pavements, PICP surfaces will require use of less de-icer and will have lower risk of slips and falls for pedestrians, and lower risk of skidding for vehicles throughout the winter.

Insoluble Particles in the Snowpack of the Ob River Basin (Western Siberia) a 2800 km Submeridional Profile

Snowpack exhibits properties that make it a unique natural archive of airborne pollution. The data on insoluble particles in the Ob River catchment (Western Siberia) snowpack are limited. Insoluble particles in the snowpack of Western Siberia were studied at 36 sites on a 2800 km submeridional profile from the city of Barnaul to Salekhard in February 2020. Snow samples were collected over the full depth of the snow core, from the surface of the snow cover to the boundary with soil, except for the lower 1–2 cm. After the filtration of melted snow through a 0.45-µm membrane, the particle composition was studied using a scanning electron microscope with an energy microprobe. In the background areas, the concentration of insoluble particles in the snow was below 2 mg/L. Significantly higher particle concentrations were encountered near cities and hydrocarbon production areas. Particulate matter in snow mainly consists of biogenic and lithogenic particles mixed with anthropogenic particles (ash and black carbon aggregates). The proportion of anthropogenic particles increases near cities and areas of active hydrocarbon production.

Storm Water Sustainable Solutions in New Cairo Using Landscape Elements

Sustainability is one of the most important requirements and standards that is taken into consideration when establishing or developing a project. It is necessary to pay sufficient attention to urban planning and study. This involves a structured form of the city and the establishment of its own cities, connecting them with different communities, providing all social and economic services for the population as well as improving the performance of the city in accordance with international standards of urban planning.Storm water is the water that remains after rain, melted snow or floods. The effects of storm water is devastating on the environment, the economy and the social environment, especially in cities. In New Cairo, this problem is still ongoing with no implemented solution and receiving insufficient attention. New Cairo has faced the risk of flooding and major traffic disruptions in most of its main roads in 2018.In this research, an attempt is made to arrive at a merger between the elements of the Landscape and the infrastructure to find sustainable solutions. This solution can limit or prevent the existence of storm water problems and discusses the possibility of developing existing cities that have problems.This will be done through analysis, study of the problem, analysis of the case study and the soil, study the elements of the Landscape. Take in consideration that the data is up to date and the solution is possible to implement to solve the problem.

Risk assessment of ice-melter reagents for urban plants

The paper assessed the phytotoxicity of the most frequently used ice-melter reagents in Moscow (sand and salt mixture, anti-freeze reagent based on a composition of calcium and sodium chloride, technical salt), snow with varying degrees of contamination of the remnants of ice-melter reagents, as well as soil after the snow cover melting. The toxicity assessment was carried out in the samples taken on the lawns along the roads in nine administrative districts of the city in places with the same anthropogenic load. The test object is oat seeds (Avena sativa), as a sensitive biotest showing the most stable and reproducible data compared to seeds from other crops. Salt solutions of reagents with dilution rates of 1, 2, 4, 6, 8 and 10, melted snow and soil extracts were used for biotesting. The phytotoxic effect was determined by comparing the average root length of control and prototype seeds. It was found that all studied ice-melter reagents have a pronounced toxic effect on oat plants even at tenfold dilution. The phytotoxic effect of snow and soil polluted with ice-melter substances, which in turn inherits the chemical composition of snow cover after its melting, was shown.

Winter air temperature in Holocene reconstructed from the ice wedges stable water isotopes near Anadyr town

The object of research is syncryogenic Holocene strata on the coast of the Onemen Bay, 2 km from the town of Anadyr. In July 2017, the outcrop of the first marine terrace uncovered by strong storms was examined. The stratigraphy of the outcrop was represented mainly by sandy loam (5–7 m thick) covered by peat (1–1.5 m) and underlain by sand. Numerous ice wedges were opened in the upper part of this outcrop. Along with that another outcropping of transect of a lakemarsh basin represented by a peat bog of 2–2.5 m thick underlain by sandy loam was also investigated. Ice wedges occur below the polygonal trenches. The present-day narrow ice wedges were found in the upper part of the peat bog. Two representative fragments of both the above outcrops were thoroughly examined. Radiocarbon dating had shown that accumulation of peat on surface of the first marine terrace started in early Holocene (about 8 ka BP). Accumulation of peatland within the lake-marsh basin was also dated to the beginning of the Holocene (about 9 ka BP). In the middle of the Holocene, it was most likely interrupted as a result of thermokarst processes and bogging of the surface. Formation of peatlands in Chukotka during the Holocene is known to be accompanied by active growth of the ice wedges inside them, so the age of the wedges studied by us was estimated as the beginning of the Holocene. The analysis of stable oxygen and hydrogen isotopes in the Holocene and the modern ice wedges had allowed establishing mainly the atmospheric type of moisture feeding of the wedges (due to melted snow) and lack of noticeable isotope fractionation during the ice formation. It has been found that δ18О and δ2Н values in the Holocene ice wedges were lower than in the modern wedges and snow by an average 2–3 and 7–12 ‰, respectively. Paleotemperature reconstructions performed on the basis of isotopeoxygen data showed that the air temperature of the coldest winter month in the first half of the Holocene in the Onemen Bay area was lower than the present-day ones by an average 2–3 °C, which is in a good agreement with the trend of rising winter temperatures throughout the Chukotka Peninsula, as well as in other areas of Eastern Siberia and Alaska.