Environmental Magnetism: The Implication of Initial Magnetic Susceptibility and Saturation Magnetization for Detecting Roadside Pollution in Arid Regions. (original) (raw)
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Environmental Geology, 2008
This work is a complementary investigation to the earlier urban soil survey for a rapidly growing city of relatively high traffic density. Therefore, it aims to apply the environmental magnetism approach to assess the roadside pollution at a known polluted site. The used magnetic proxies are the initial magnetic susceptibility and saturation magnetization. The results prove the applicability of this method in detecting roadside pollution. The shape and magnitude of the magnetic signals was affected by the topography and prevailing wind direction that caused the magnetic peaks to be shifted accordingly. Particle size was found to affect the magnetic material content, where sand size (63-150 lm) bears the highest magnetic signals relative to smaller silt size (<63 lm). The magnetic anomalies coincided positively with heavy metal pollution in the studied site, which might indicate that the magnetic materials serve as an effective proxy for the metallic pollution (i.e., Fe, Ni, Pb, Cu, and Zn) originated mainly from vehicular sources.
current science, 2021
Among the several methods to determine anthropogenic pollutants in the soil, magnetic susceptibility measurements have proven to be useful for rapid and effective diagnosis of magnetic particles and overall screening of pollution. Magnetic particles and other heavy metals accumulated in the topsoil as a result of roadside pollution, contribute to the bulk magnetic susceptibility (χ ). Thus, χ values of the soil can be utilized as a proxy to delineate the zones of high and low roadside pollution in an area. In this study, magnetic susceptibility measurements of the topsoil have been carried out and a quantitative assessment of roadside pollution in the Banaras Hindu University (BHU) campus, Varanasi, India is presented. Based on the χ values of 212 soil samples covering 1300 acres of the campus, zones of high and low roadside pollution are demarcated. The present study has not only deciphered the spatial variation of pollutants in the BHU campus, but has also characterized the magnetic phases responsible for the susceptibility signal on the roadsides inside the campus. The obtained results are crucial for environmental monitoring and prioritization of land use and other anthropogenic activities inside the BHU campus. The modus operandi adopted here would be beneficial for mapping areas exposed to different levels of pollution intensity, for tracing the pollution transport and can be effectively applied to various ecosystems.
2016
This research work presents a study on the application of magnetic susceptibility measurements and geochemical analysis for mapping or assessing heavy metal pollution in the agricultural soil in road proximity. The research work was also done to check any runoff of heavy metals pollution to the Owabi dam which serves as the main water sources to catchment areas and the whole of Kumasi Metropolis. This research work was conducted along the asphalt road closed to Amamfrom Community in the southern part of Ghana. The study revealed that magnetic susceptibility measurements can be used as a proxy and fastest method of determining heavy metal pollution in agricultural soils. The results showed three most important trends: 1) the samples collected near the road have higher values of magnetic susceptibility and mean heavy metals content than those collected far from the road exhaust; 2) some of the sample areas undisturbed by erosion and weathering have significant magnetic susceptibility ...
International Journal of Environmental Science and Technology, 2017
The use of mineral magnetic techniques as pollution proxy for road deposited sediment was explored using various statistical approaches. Standard techniques were adopted for measurement of mineral magnetic and geochemical parameters. The analyses of magnetic parameters revealed that the samples were dominated by ferrimagnetic minerals and multidomain grains. This implied that the magnetic fractions in the samples might be of anthropogenic origin. Results also indicate that the samples were dominated by low coercive, magnetically soft minerals. Thermomagnetic curves confirmed magnetite as the remanence bearing magnetic mineral having a Curie point temperature of *580°C. The strong association observed between magnetic susceptibility, susceptibility of anhysteric remanent magnetization and saturation isothermal remanent magnetization and aluminum, titanium, manganese, iron, chromium and lead demonstrated that these metals occurred as ferrimagnetic particles of technogenic origin resulting from vehicular sources. Assessment of pollution status of the road deposited sediment identified silicon and lead as the priority pollutants of concern. Generally, pollution load index was \1 (mean, 0.66 ± 0.14), indicating that the samples were not polluted in the overall, but the metals were in the buildup stage requiring constant monitoring. The sources of pollutants from principal component and cluster analyses identified the sources of pollution to be mainly from vehicular emissions such as brake linings, exhaust materials, tire wear, corroded metal parts, abrasion of lubricating oil and road construction materials. This study found that mineral magnetic techniques offer great potential as pollution proxy for soil pollution studies.
This research work presents a study on the application of magnetic susceptibility measurements and geochemical analysis for mapping or assessing heavy metal pollution in the agricultural soil in road proximity. The research work was also done to check any runoff of heavy metals pollution to the Owabi dam which serves as the main water sources to catchment areas and the whole of Kumasi Metropolis. This research work was conducted along the asphalt road closed to Amamfrom Community in the southern part of Ghana. The study revealed that magnetic susceptibility measurements can be used as a proxy and fastest method of determining heavy metal pollution in agricultural soils. The results showed three most important trends: 1) the samples collected near the road have higher values of magnetic susceptibility and mean heavy metals content than those collected far from the road exhaust; 2) some of the sample areas undisturbed by erosion and weathering have significant magnetic susceptibility and heavy metals contents; 3) some of the sample areas washed away by erosion are believed to be deposited in Owabi Dam due to their low ground reliefs. Therefore, future research should concentrate on Owabi Dam which may be polluted by the runoff from these heavy metals.
… of the Earth, Parts A/B/C, 2004
Magnetic methods provide a fast tool for delineation of industrial pollution. Mineral magnetic studies of anthropogenic magnetic phases in road dust from the industrial zone of Visakhapatnam city (India) reveal the presence of large anthropogenic spherules with diameters up to $300 lm. Different internal structures of the spherules and a wide variation in size of the spherules, as well as the presence of melt-like particles and irregular shaped grains containing heavy metals, point to multiple sources of pollution, including different industries and heavy vehicle traffic. Magnetic mineralogy of the samples is dominated by a magnetite-like phase. Hysteresis parameters measured for magnetic extracts and single grains, are typical for pseudo-single domain magnetite. This is in disagreement with the large grain size of the single particles. Scanning electron microscopy images reveals a complex internal structure, showing an agglomeration of smaller grains and in-part, an extreme porosity of the spherules, probably related to fast cooling. The chemical composition determined by energy dispersive X-ray analysis is strongly variable and can also be very heterogeneous within a particle. First order reversal curve analysis indicates a spectrum of single domain, pseudo-single domain and multidomain properties. Values of saturation magnetisation suggest that the particles either consist of mainly similar ferrimagnetic sub-grains, whereas others are a mixture of ferrimagnetic and non-magnetic phases. Several irregular grains, showing a ferrimagnetic behaviour, contain a large amount of chromium (>50 wt%). The variations of the magnetic susceptibility along the three major roads in the industrial zone of Visakhapatnam are interpreted in terms of the relative degree of pollution.
Air Pollution XV, 2007
The use of mineral magnetic concentration parameters (χ LF , χ ARM and SIRM) as a potential particle size proxy for urban street dust collected from Southport (Merseyside, UK) is explored. Correlation analyses between each magnetic parameter and traditional particle size classes (i.e. sand, silt and clay) and respiratory health related size classes (i.e. PM 10 , PM 2.5 and PM 1.0) are reported. Significant relationships (p <0.001; n = 50) exist between sand, silt and clay content with at least one or all of the magnetic concentration parameters. This is also the same for each PM 10 , PM 2.5 and PM 1.0 sizes. Of the three magnetic parameters, χ LF displays the strongest correlation values (r = 0.701, P <0.001, n = 50) and is the most significant parameter, which is consistent with all class sizes of each approach. In doing so, these associations indicate mineral magnetic measurements have considerable potential as a particle size proxy for determining urban roadside particulate matter concentrations. Given the speed, low-cost and sensitivity of the measurements, this suggests magnetic techniques could potentially be used as an alternative and/or complementary exploratory technology for pilot particulate pollution investigations. Furthermore, in certain instances, it could be useful for examining linkages between respiratory health and particulate pollution and vehicle emissions.
A total of 115 urban soil samples collected on grid bases from Al-Karak, South Jordan, were investigated for their field and dual-frequency magnetic susceptibility (vfield, vd) and heavy metal content using Bartington susceptibility meters and ICP-MS. The upper soils have higher magnetic susceptibility values than lower soils, and large particles contain more heavy metals and higher magnetic susceptibility than smaller particles. This might be attributed to the lack of pedogenesis due to arid climate influence. Within the upper soil all heavy metal showed positive significant correlation with upper soil low-frequency vdlf. This was evident from the distribution maps produced by Surfer 9.0 for vdlf and heavy metals. The results showed that higher vdlf is associated with traffic-dominated sites more than other areas. The frequency-dependent susceptibility (vfd %) falls between 2 and 10 %, which indicate the presence of admixture of fine supermagnetic particles. Mildly correlation exists between vfd % and vdlf, which implies that soils contain anthropogenic multi-domain grains. Selected samples have been analyzed for their mineral constituents; the results indicate the presence of magnetite as the main magnetic mineral. This confirms the anthropogenic source of pollution mainly from the vehiclerelated materials. The results indicate the applicability of magnetic susceptibility for pollution detection.
EGU General Assembly Conference Abstracts, 2012
A total of 115 urban soil samples collected on grid bases from Al-Karak, South Jordan, were investigated for their field and dual-frequency magnetic susceptibility (v field , v d) and heavy metal content using Bartington susceptibility meters and ICP-MS. The upper soils have higher magnetic susceptibility values than lower soils, and large particles contain more heavy metals and higher magnetic susceptibility than smaller particles. This might be attributed to the lack of pedogenesis due to arid climate influence. Within the upper soil all heavy metal showed positive significant correlation with upper soil low-frequency v dlf. This was evident from the distribution maps produced by Surfer 9.0 for v dlf and heavy metals. The results showed that higher v dlf is associated with traffic-dominated sites more than other areas. The frequency-dependent susceptibility (vfd %) falls between 2 and 10 %, which indicate the presence of admixture of fine supermagnetic particles. Mildly correlation exists between vfd % and v dlf , which implies that soils contain anthropogenic multi-domain grains. Selected samples have been analyzed for their mineral constituents; the results indicate the presence of magnetite as the main magnetic mineral. This confirms the anthropogenic source of pollution mainly from the vehiclerelated materials. The results indicate the applicability of magnetic susceptibility for pollution detection.
Water, Air & Soil Pollution , 2022
This study is close to an earlier urban soil survey carried out for a rapidly growing city with a high traffic density in Aurangabad city, India. Consequently, it aims to use the environmental magnetism approach to assess roadside emissions at a known polluted site. Magnetic measurements have been successfully implemented in soil studies and seem to be a suitable approach for pollution assessment in industrial and roadside areas of the study area. The present study was accomplished for magnetic susceptibility, isothermal remanent magnetization, coercivity, hysteresis measurements, thermomagnetic curves, scanning electron microscopy, and energy-dispersive spectroscopy analysis to evaluate the absolute fraction of magnetic minerals in bulk soil samples. The soils displayed variation in magnetic susceptibility values, which was influenced by concentration, domain states, and morphological characteristics of magnetic minerals. Substantial variation in the mineralogical composition of soils deriving from different industrial activities was noticed. The results indicate that industrial and roadside soil samples with mostly coarser and irregular-shaped show ferrimagnetic minerals. The presence of iron-titanium combination in most of the samples is due to titanomagnetite accompanying the titanium-bearing grains. In soils, a higher amount of ferrimagnetic minerals (magnetite, titanomagnetite, maghemite) with a minor content of antiferromagnetic minerals (hematite/goethite) was noticed. These studies reveal that magnetic and morphological characterization of soils can be used as an appropriate tracer for industrial and roadside soil pollution, which leads to new avenues for more detailed chemical mapping.