This work focuses on the analysis of the chemical composition of soils dedicated to agriculture in order to assess the impacts of manganese mining activity in the city of Moanda in South-East Gabon. The result of the ...This work focuses on the analysis of the chemical composition of soils dedicated to agriculture in order to assess the impacts of manganese mining activity in the city of Moanda in South-East Gabon. The result of the analysis obtained using wavelength dispersive X-ray fluorescence revealed the presence of twenty-seven elements in the seventeen soil samples collected namely: Na, K, Rb, Mg, Ca, Sr, Ba, Ti, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Cr, Mn, Al, O, C, P, S, Si, I, Ac and Th. Iron (Fe), aluminum (Al) and manganese (Mn) were respectively higher. The practice of agriculture near mining sites is not without risks for the quality of agricultural products and the health of the population.展开更多
Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in therm...Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.展开更多
The objective of this study was to establish a baseline for future studies that aim to determine possible contamination from human, agricultural and industrial activities. As well as the determination of the indices o...The objective of this study was to establish a baseline for future studies that aim to determine possible contamination from human, agricultural and industrial activities. As well as the determination of the indices of environmental or geological contamination and enrichment factors of heavy metals Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in agricultural soils of Constanza, Jarabacoa, Rancho Arriba and San José de Ocoa (SJO), municipalities located in the valleys of the Central mountain range of the Dominican Republic. The determination of the concentrations of heavy metals was carried out using the X-ray Fluorescence technique. Just like in Azua, San Juan de la Maguana (SJM) y Barahona in the southwest. Producer municipalities of vegetables, rice, beans, corn, melon, watermelon, tomato, banana, avocado, sugar cane and fodder for cattle. The concentration of 160 mg·kg<sup>-1</sup> Probable Effect Level (PEL) of Cr according to the SQuiRTs table (USEPA-NOAA) for agricultural soils, were exceeded in 50% of the samples in SJM, SJO, Jarabacoa and Constanza;in Barahona and Azua by 20%. The PEL of 42.8 mg·kg-1</sup><sup></sup> of the Ni was higher in more than 50% of the samples from SJM, Azua, Barahona and Jarabacoa;in SJO and Constanza at 35%. In the case of Cu with a PEL of 108 mg·kg-1</sup><sup></sup> in SJO and Constanza, 5% of the samples exceeded its, in the other areas the concentrations were lower. Zn, As and Pb did not manage to exceed their respective PEL.展开更多
To assess the effectiveness of vacuum preloading combined electroosmotic strengthening of ultra-soft soil and study the mechanism of the process, a comprehensive experimental investigation was performed. A laboratory ...To assess the effectiveness of vacuum preloading combined electroosmotic strengthening of ultra-soft soil and study the mechanism of the process, a comprehensive experimental investigation was performed. A laboratory test cell was designed and applied to evaluate the vacuum preloading combined electroosmosis. Several factors were taken into consideration, including the directions of the electroosmotic current and water induced by vacuum preloading and the replenishment of groundwater from the surrounding area. The results indicate that electroosmosis together with vacuum preloading improve the soil strength greatly, with an increase of approximately 60%, and reduce the water content of the soil on the basis of consolidation of vacuum preloading, howeve~ further settlement is not obvious with only 1.7 mm. The reinforcement effect of vacuum preloading combined electroosmosis is better than that of electroosmosis after vacuum preloading. Elemental analysis using X-ray fluorescence proves that the soil strengthening during electroosmotic period in this work is mainly caused by electroosmosis-induced electrochemical reactions, the concentrations of Al2O3 in the VPCEO region increase by 2.2%, 1.5%, and 0.9% at the anode, the midpoint between the electrodes, and the cathode, respectively.展开更多
Soil minerals study is vital in terms of investigating the major soil forming compounds and to find out the fate of minor and trace elements in soils. It is also essential for the soil-plant interaction purpose. To id...Soil minerals study is vital in terms of investigating the major soil forming compounds and to find out the fate of minor and trace elements in soils. It is also essential for the soil-plant interaction purpose. To identify soil mineral phases especially clay minerals, X-ray diffraction (XRD) has been a popular technique. The clay mineralogical information of soils in Bangladesh is limited, especially in Ganges flood plain region (Agro Ecological Zone (AEZ) 12 and 13). Therefore, to overcome this limitation, in this study, we performed XRD analysis of <2 mm fractions soil samples of AEX 12 and 13. However, identifying mineralogical phases by XRD in <2 mm fractions soils is not so straight-forward due to many practical problems. We fully matched only two mineralogical phases in all the soil samples which is quartz and potassium-Aluminum-Silicate. However, the full XRD peaks indicate that more minerals are also present, but due to heterogeneity of soils samples, it is difficult to find other minerals phases by only XRD peak of <2 mm fractions. Therefore, to find more information about mineralogical phases, we performed XRF analysis that provides the elemental composition of minerals phase as oxide. XRF analysis indicated the presence of secondary minerals like illite and chlorite. The presence of high percentage Fe oxide not only indicated the iron mineral phase (goethite and ferrihydrite) but also indicated iron rich high charge smectite minerals (beidellite). The presence of iron rich smectite minerals in the Ganges sediments reported in several previous studies. Thus, we concluded that only XRD in <2 mm fractions of soils is not adequate to identify the mineralogical phases of soil samples. Others analyses like XRF, XRD in <2 μm fractions will be necessary to locate an entire image of soil mineralogical phases.展开更多
In Dominican Republic exists cultive larges fields of various agricultural rubles. The largest extensions are rice, banana and cocoa;these are located in the Cibao Valley. In the eastern, southwestern, and a small are...In Dominican Republic exists cultive larges fields of various agricultural rubles. The largest extensions are rice, banana and cocoa;these are located in the Cibao Valley. In the eastern, southwestern, and a small area in the north of the country, sugar cane is cultivated. Heavy metals are found in many of these soils that could be affecting the quality of agricultural products or production. The levels of Cr, Ni, Zn, Cu, Cd, As, Hg and Pb, determined by X-ray fluorescence spectroscopy, in soils collected in two cultivation areas of Rice de La Vega and San Francisco de Macoris (SFM) have been compared with the NOAA-USEPA Canadian Agricultural Soil and Sediment Guide (CEQGs) (SQuiRTs Table). The levels of Cr and Ni in La Vega exceeded the threshold effects levels (TEL), and the probable effects levels (PEL). Pb levels in the La Vega area were higher than in SFM. In general, these metals are found in the La Vega area in higher concentrations than in SFM, exceeding PEL and TEL.展开更多
This study aims to investigate the combined use of multi-sensor datasets(Landsat 4–5&8 OLI satellite imagery,spatial resolution=30 m)coupled with field studies to evaluate spatio-temporal dynamics of soil saliniz...This study aims to investigate the combined use of multi-sensor datasets(Landsat 4–5&8 OLI satellite imagery,spatial resolution=30 m)coupled with field studies to evaluate spatio-temporal dynamics of soil salinization along the coastal belt in West Bengal,India.This study assesses soil salinization by mapping the salinity and electrical conductivity of saturation extract(ECe)and utilizing spectral signatures for estimating soil salinity.The SI change(%)was analyzed(2021–1995),categorizing increases in salinity levels into 5%,10%,and 50%changes possibly due to salt encrustation on the soil layers.The land use land cover(LULC)change map(2021–1995)demonstrates that the study area is continuously evolving in terms of urbanization.Moreover,in the study area,soil salinity ranges from 0.03 ppt to 3.87 ppt,and ECe varies from 0.35 dSm^(-1)to 52.85 dSm^(-1).Additionally,vulnerable saline soil locations were further identified.Classification of soil salinity based on ECe reveals that 26%of samples fall into the nonsaline category,while the rest belong to the saline category.The Spectral signatures of the soil samples(n=19)acquired from FieldSpec hand spectrometer show significant absorption features around 1400,1900,and 2250 nm and indicate salt minerals.The results of reflectance spectroscopy were crossvalidated using X-ray fluorescence and scanning electron microscopy.This study also employed partial least square regression(PLSR)approach to predict ECe(r^(2)=0.79,RMSE=3.29)and salinity parameters(r^(2)=0.75,RMSE=0.51),suggesting PLSR applicability in monitoring salt-affected soils globally.This study’s conclusion emphasizes that remote sensing data and multivariate analysis can be crucial tools for mapping spatial variations and predicting soil salinity.It has also been concluded that saline groundwater used for irrigation and aqua-cultural activities exacerbates soil salinization.The study will help policymakers/farmers identify the salt degradation problem more effectively and adopt immediate mitigation measures.展开更多
近年来,我国进一步加强了对矿产资源调查工作的重视程度,使矿产资源调查成果更加科学、准确。大量研究成果表明,X射线荧光光谱法(XRF)通过具有高自动化、快速分析速度和良好的重现性特点的分析仪器,目前在水泥、地质、化工、冶金等领域...近年来,我国进一步加强了对矿产资源调查工作的重视程度,使矿产资源调查成果更加科学、准确。大量研究成果表明,X射线荧光光谱法(XRF)通过具有高自动化、快速分析速度和良好的重现性特点的分析仪器,目前在水泥、地质、化工、冶金等领域得到了极其广泛的应用,尤其是地质样品分析中。本文主要采用Axios m AX(最大功率4000瓦)仪器对土壤样品中的Cu、Pb、Zn、As、Sb、Co、Cr、Ni等多种金属元素进行测量。展开更多
文摘This work focuses on the analysis of the chemical composition of soils dedicated to agriculture in order to assess the impacts of manganese mining activity in the city of Moanda in South-East Gabon. The result of the analysis obtained using wavelength dispersive X-ray fluorescence revealed the presence of twenty-seven elements in the seventeen soil samples collected namely: Na, K, Rb, Mg, Ca, Sr, Ba, Ti, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Cr, Mn, Al, O, C, P, S, Si, I, Ac and Th. Iron (Fe), aluminum (Al) and manganese (Mn) were respectively higher. The practice of agriculture near mining sites is not without risks for the quality of agricultural products and the health of the population.
基金supported by National Energy R&D Center of Petroleum Refining Technology of China(RIPP,SINOPEC)National Key Research and Development Program of China(No.2017YFA0304203)+5 种基金Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT_17R70)National Natural Science Foundation of China(Nos.61975103,61875108,61775125 and 11434007)Industrial Application Innovation Project(No.627010407)Scientific and Technological Innovation Project of Shanxi Gemeng US-China Clean Energy R&D Center Co.,Ltd111 Project(D18001)Fund for Shanxi‘1331KSC’。
文摘Although laser-induced breakdown spectroscopy(LIBS),as a fast on-line analysis technology,has great potential and competitiveness in the analysis of chemical composition and proximate analysis results of coal in thermal power plants,the measurement repeatability of LIBS needs to be further improved due to the difficulty in controlling the stability of the generated plasmas at present.In this paper,we propose a novel x-ray fluorescence(XRF) assisted LIBS method for high repeatability analysis of coal quality,which not only inherits the ability of LIBS to directly analyze organic elements such as C and H in coal,but also uses XRF to make up for the lack of stability of LIBS in determining other inorganic ash-forming elements.With the combination of elemental lines in LIBS and XRF spectra,the principal component analysis and the partial least squares are used to establish the prediction model and perform multi-elemental and proximate analysis of coal.Quantitative analysis results show that the relative standard deviation(RSD) of C is 0.15%,the RSDs of other elements are less than 4%,and the standard deviations of calorific value,ash content,sulfur content and volatile matter are 0.11 MJ kg,0.17%,0.79% and 0.41%respectively,indicating that the method has good repeatability in determination of coal quality.This work is helpful to accelerate the development of LIBS in the field of rapid measurement of coal entering the power plant and on-line monitoring of coal entering the furnace.
文摘The objective of this study was to establish a baseline for future studies that aim to determine possible contamination from human, agricultural and industrial activities. As well as the determination of the indices of environmental or geological contamination and enrichment factors of heavy metals Cr, Ni, Cu, Zn, As, Cd, Hg and Pb in agricultural soils of Constanza, Jarabacoa, Rancho Arriba and San José de Ocoa (SJO), municipalities located in the valleys of the Central mountain range of the Dominican Republic. The determination of the concentrations of heavy metals was carried out using the X-ray Fluorescence technique. Just like in Azua, San Juan de la Maguana (SJM) y Barahona in the southwest. Producer municipalities of vegetables, rice, beans, corn, melon, watermelon, tomato, banana, avocado, sugar cane and fodder for cattle. The concentration of 160 mg·kg<sup>-1</sup> Probable Effect Level (PEL) of Cr according to the SQuiRTs table (USEPA-NOAA) for agricultural soils, were exceeded in 50% of the samples in SJM, SJO, Jarabacoa and Constanza;in Barahona and Azua by 20%. The PEL of 42.8 mg·kg-1</sup><sup></sup> of the Ni was higher in more than 50% of the samples from SJM, Azua, Barahona and Jarabacoa;in SJO and Constanza at 35%. In the case of Cu with a PEL of 108 mg·kg-1</sup><sup></sup> in SJO and Constanza, 5% of the samples exceeded its, in the other areas the concentrations were lower. Zn, As and Pb did not manage to exceed their respective PEL.
基金Project(2009B13014) supported by the Fundamental Research Funds for the Central Universities of ChinaProject(IRT1125) supported by the Program for Changjiang Scholars and Innovative Research Team in University,China
文摘To assess the effectiveness of vacuum preloading combined electroosmotic strengthening of ultra-soft soil and study the mechanism of the process, a comprehensive experimental investigation was performed. A laboratory test cell was designed and applied to evaluate the vacuum preloading combined electroosmosis. Several factors were taken into consideration, including the directions of the electroosmotic current and water induced by vacuum preloading and the replenishment of groundwater from the surrounding area. The results indicate that electroosmosis together with vacuum preloading improve the soil strength greatly, with an increase of approximately 60%, and reduce the water content of the soil on the basis of consolidation of vacuum preloading, howeve~ further settlement is not obvious with only 1.7 mm. The reinforcement effect of vacuum preloading combined electroosmosis is better than that of electroosmosis after vacuum preloading. Elemental analysis using X-ray fluorescence proves that the soil strengthening during electroosmotic period in this work is mainly caused by electroosmosis-induced electrochemical reactions, the concentrations of Al2O3 in the VPCEO region increase by 2.2%, 1.5%, and 0.9% at the anode, the midpoint between the electrodes, and the cathode, respectively.
文摘Soil minerals study is vital in terms of investigating the major soil forming compounds and to find out the fate of minor and trace elements in soils. It is also essential for the soil-plant interaction purpose. To identify soil mineral phases especially clay minerals, X-ray diffraction (XRD) has been a popular technique. The clay mineralogical information of soils in Bangladesh is limited, especially in Ganges flood plain region (Agro Ecological Zone (AEZ) 12 and 13). Therefore, to overcome this limitation, in this study, we performed XRD analysis of <2 mm fractions soil samples of AEX 12 and 13. However, identifying mineralogical phases by XRD in <2 mm fractions soils is not so straight-forward due to many practical problems. We fully matched only two mineralogical phases in all the soil samples which is quartz and potassium-Aluminum-Silicate. However, the full XRD peaks indicate that more minerals are also present, but due to heterogeneity of soils samples, it is difficult to find other minerals phases by only XRD peak of <2 mm fractions. Therefore, to find more information about mineralogical phases, we performed XRF analysis that provides the elemental composition of minerals phase as oxide. XRF analysis indicated the presence of secondary minerals like illite and chlorite. The presence of high percentage Fe oxide not only indicated the iron mineral phase (goethite and ferrihydrite) but also indicated iron rich high charge smectite minerals (beidellite). The presence of iron rich smectite minerals in the Ganges sediments reported in several previous studies. Thus, we concluded that only XRD in <2 mm fractions of soils is not adequate to identify the mineralogical phases of soil samples. Others analyses like XRF, XRD in <2 μm fractions will be necessary to locate an entire image of soil mineralogical phases.
文摘In Dominican Republic exists cultive larges fields of various agricultural rubles. The largest extensions are rice, banana and cocoa;these are located in the Cibao Valley. In the eastern, southwestern, and a small area in the north of the country, sugar cane is cultivated. Heavy metals are found in many of these soils that could be affecting the quality of agricultural products or production. The levels of Cr, Ni, Zn, Cu, Cd, As, Hg and Pb, determined by X-ray fluorescence spectroscopy, in soils collected in two cultivation areas of Rice de La Vega and San Francisco de Macoris (SFM) have been compared with the NOAA-USEPA Canadian Agricultural Soil and Sediment Guide (CEQGs) (SQuiRTs Table). The levels of Cr and Ni in La Vega exceeded the threshold effects levels (TEL), and the probable effects levels (PEL). Pb levels in the La Vega area were higher than in SFM. In general, these metals are found in the La Vega area in higher concentrations than in SFM, exceeding PEL and TEL.
基金PK thanks Banaras Hindu University(BHU)for providing the University Fellowship(R/Dev/Sch/UGC Research Fellow/2020-21/18340)and Credit Incentive to Research ScholarsPK expresses gratitude to Dr.Abhinav Yadav(IESD,BHU)for his assistance during the laboratory procedures for soil analysis.PK acknowledges the XRF facility at the Sophisticated Analytical&Technical Help Institute(SATHI)at central discovery centre,BHU,and Scanning Electron Microscopy Laboratory,Geology,BHU,for instrumental support.AB acknowledges the University Grant Commission for funding this work as a start-up Research Grant(No.F.30-431/2018-BSR)AB would also like to thank Banaras Hindu University for utilizing partial funds from the Bridge Grant(Development Scheme number 6031-A)under the Institution of Eminence(IoE)program to the University。
文摘This study aims to investigate the combined use of multi-sensor datasets(Landsat 4–5&8 OLI satellite imagery,spatial resolution=30 m)coupled with field studies to evaluate spatio-temporal dynamics of soil salinization along the coastal belt in West Bengal,India.This study assesses soil salinization by mapping the salinity and electrical conductivity of saturation extract(ECe)and utilizing spectral signatures for estimating soil salinity.The SI change(%)was analyzed(2021–1995),categorizing increases in salinity levels into 5%,10%,and 50%changes possibly due to salt encrustation on the soil layers.The land use land cover(LULC)change map(2021–1995)demonstrates that the study area is continuously evolving in terms of urbanization.Moreover,in the study area,soil salinity ranges from 0.03 ppt to 3.87 ppt,and ECe varies from 0.35 dSm^(-1)to 52.85 dSm^(-1).Additionally,vulnerable saline soil locations were further identified.Classification of soil salinity based on ECe reveals that 26%of samples fall into the nonsaline category,while the rest belong to the saline category.The Spectral signatures of the soil samples(n=19)acquired from FieldSpec hand spectrometer show significant absorption features around 1400,1900,and 2250 nm and indicate salt minerals.The results of reflectance spectroscopy were crossvalidated using X-ray fluorescence and scanning electron microscopy.This study also employed partial least square regression(PLSR)approach to predict ECe(r^(2)=0.79,RMSE=3.29)and salinity parameters(r^(2)=0.75,RMSE=0.51),suggesting PLSR applicability in monitoring salt-affected soils globally.This study’s conclusion emphasizes that remote sensing data and multivariate analysis can be crucial tools for mapping spatial variations and predicting soil salinity.It has also been concluded that saline groundwater used for irrigation and aqua-cultural activities exacerbates soil salinization.The study will help policymakers/farmers identify the salt degradation problem more effectively and adopt immediate mitigation measures.
文摘近年来,我国进一步加强了对矿产资源调查工作的重视程度,使矿产资源调查成果更加科学、准确。大量研究成果表明,X射线荧光光谱法(XRF)通过具有高自动化、快速分析速度和良好的重现性特点的分析仪器,目前在水泥、地质、化工、冶金等领域得到了极其广泛的应用,尤其是地质样品分析中。本文主要采用Axios m AX(最大功率4000瓦)仪器对土壤样品中的Cu、Pb、Zn、As、Sb、Co、Cr、Ni等多种金属元素进行测量。
