جستجوی مقالات مرتبط با کلیدواژه "soil contamination" در نشریات گروه "جغرافیا"

Mines and their related-industries are able to affect their surrounding environment, not only by their activities, but also after being abandoned. Among their different harmful effects, under water and surface water contaminations, and soil contamination can be mentioned. In order to manage these environmental effects, it is necessary to use reasonable methods for modelling heavy metal concentration in soil. This study aims to present a framework for modelling heavy metal soil contamination based on spectroscopy and statistical models. For this purpose, the spectral curves of the 53 soil samples, derived from an abandoned mine and its surrounding areas in New South Wales, Australia, were collected using a spectroradiometer in visible to short wavelength infrared (SWIR) wavelengths. Calculating the second derivative of the collected spectral data, random forest feature selection method (RFFS) was used to determine the most important spectral data for modelling heavy metal concentrations including lead, silver, cadmium and mercury. Then, the modelling techniques including multiple linear regression, random forest regression, and support vector regression (SVR) were applied on the selected spectral data. The results indicated that SWIR wavelengths are the most important spectral data for modelling heavy metal concentrations. Moreover, the non-linear machine learning methods, especially random forest with RMSE of 0.8 ppm and R2 of 0.51 for lead and RMSE of 9.4 ppm and R2 of 0.46 for cadmium performed better than multiple linear regression.

Atmospheric emissions from industrial establishments are one of the major sources of environmental pollution. One type of industry that causes particle pollution is the cement industry that Heavy metals are among the most relevant substances emitted during the process of cement manufacture. The aim of the study is to determine the major source and extent of metal pollution in soils vicinity of the cement factory in Behbahan city. Therefore, sixty one soil samples were collected from around the cement factories in Bebahan area. The samples were obtained at the depth 5-10 cm and were analyzed for Al, Pb, Cd and Ni by Inductively Coupled Plasma (ICP). In the samples of the studied soil, the average of the recorded concentration of elements for Al, Pb, Cd and Ni are 83.26, 64.69, 75.29 and 64 (ppm), respectively. The order of the average frequency of the heavy metals concentration is of Al>Cd>Pb>Ni. The results further revealed that the metal distribution were in a fluctuating manner considering various distances and directions from the cement facility, as it was observed that the mean metal concentrations of the soil decrease as distance from the cement facility increased for most metals. In this study, three contamination indexes have been used to express the distribution of soil pollution in the area. The result of the present study showed that all the metals were deficiency to minimal enriched in all distances, since the EF values of the metals are smaller than 1.5. Geoaccumulation index of the soil sampling can explain that the Cd element is lying with extremely contaminated area and the Pb element is lying with low contaminated area. The PLI was calculated for the overall distances and showed uncontaminated area than heavy metals in background value.