Characteristics of Coal Ashes in Yanzhou Mining District and Distribution of Trace Elements in Them

In the process of combustion of coal organic and inorganic materials in it will undergo a complex variation.Part of thew will become volatiles and,together with coal smoke,enter into atmosphere,some will remain in micro-particulates such as ash and dust and find their way into atmosphere in the form of solid particles,and the rest will be retained in ash and slag.Coal ashes are the residues of organic and inorganic substances in coal left after coal combustion and the compostition of coal ashes in dependent on that of minerals and organic matter in coal.This paper deals with the chemical composition of coal ashes,the distribution of trace elements in them and their petrological characteristics,and also studies the relationship between the yield of coal ashes and the distribution of trace elements.In addition,a preliminary study in also undertaken on the factors that affect the chemical composition of coal ashes.As viewed from the analyses of coal ash samples collected from the Yanzhou mining district,it can be seen clearly that coal ashes from the region studied are composed chiefly of crystalline materials,glassy materials and uncombusted organic matter and the major chemical compositions are SiO2,Al2O3,Fe2O3,and CaO,as well as minor amounts of SO3,PWO5,Na2O,K2O and TiO2.During the combustion of coal,its trace elements will be redistributed and most of them are enriched in coal ashes.At the same time,the concentrations of the trace elements in flying ash are much higher than those of bottom ash,i.e.,with decreasing particle-size of coal ashes their concentrations will become higher and higher.So the contents of trace elements are negatively proportional to the particle-size of coal ashes.There has been found a positive correlation between the trace elements Th.V.Zn,Cu and Pb and the yield of coal ashes while a negative correlation between Cl and the yield of coal ashes.     

Enrichment of Cd and Pb and associations with grain size in sediments in Nanjing alluvial island of Yangtze River

Intermittence belts of metal contaminated sediment have been formed along the urban riverside of the Yangtze River because of rapid urbanization and industrial development during the last three decades. Baguazhou Island, the third alluvial island in the lower reaches of the Yangtze River, was chosen to assess the contaminations level of Cd, Pb, Ni, Cr, Cu and Zn in suspended particulate matter （SPM）, recent sediments and sediment-derived soils. The relations between the metal concentrations and the grain size distributions in sediments were analyzed in order to explore the association of heavy metal settling with sediment deposition. The results showed that significantly high levels of Cd and Pb in SPM dominated enrichment factors （EFs） of recent sediments in the area of Baguazhou Island. High levels of Cd and Pb were found both in the riverine sediments and in the soils. However, the average levels of Cd and Pb in sediments were almost as twice as those in soil. About 43% of all sediment samples have EFCd≥1.5 and 14% with EFCd≥2. There are about 21% of the samples with EFPb≥1.5 and none of them has EFPb≥2. Meanwhile, soil samples with EFCd≥1.5 account for 39% of all 64 samples and no one with EFPb≥1.0. Most of the sediment samples contain more than 80% of fine grains lower than 60 μm in size, and few samples located in the site where flow eroding process dominates contain fine grains lower than 30%. Correlation analysis indicated that the concentrations of Cd and Pb in the sediments have significant relationships with grain size.     

Geochemical characterization of soils, sediments and waters around active and abandoned dumpsites in Lagos

In developing countries, large amounts of wastes are dumped daily in open dumping sites without proper management. This practice usually causes enhanced concentration of metallic ions in environmental media within and beyond the vicinity of such dumps with attendant adverse environmental and health risks. Hence the aim of this study is to assess and elucidate the physico- and metallic ions concentrations in three environmental media （soils, sediments and waters） around active （Ojota） and abandoned （Isolo） dumpsites in Lagos and also to do a comparative study with reference to possible environmental and health impacts. A total of eighty samples comprising water, sediments and topsoils were collected around the two dumpsites. The soil and sediment were dried, disaggregated and sieved to 〈75 μm fraction for analysis of the metallic ions using aqua-regia digestion technique and Inductively Coupled Plasma Mass Spectrometry （ICP-MS）. The analysis of metallic ions and cations in water was carried out using Inductively Coupled Plasma-Optical Emission Spectrometry （ICP-OES） while unacidified water samples were analyzed for anions concentrations using the DIONEX DX-120 Ion Chromatography techniques. Analytical results show that pH, NO3, Fe, Mn and Na in most of the water samples are above WHO and EPA standards. Also there are relatively strong correlations between NO3 and Cl, SO4, Coliform, TDS and EC which are an indicator of water contamination especially in the direction of groundwater flow. The mean values of the significant metallic ions present in the water samples include Cu （16.29 and 38.0）, Zn （535.71 and 667.0）, A1 （0.27 and 0.19）, Ba （42.86 and 55.0）, Sr （80.0 and 136.0） and B （118.7 and 160.2） for active （Ojota） and abandoned （Isolo） dnmpsites respectively. Soil samples revealed varied concentrations with the estimated average contamination factors of 3.86 and 5.71 （As）, 1.60 and 1.93 （Mo）, 3.41 and 4.24 （Zn）, 0.93 and 2.23 （Cu）, 7.71 and 12.64 （Pb）, 8.71 and 9.21（Cd） for both active and abandoned sites respectively. All these metals with Ag are also significant and follow the same trend in the sediments. Ag, Bi, Sb, Ga, Sc, Mn, Ga and La in soil samples are only significant for samples close to the dnmpsites while Bi, Be, Sb, Co, Cu, La and Cr are significant for sediments taken downstream. Most of the metallic ions show significant enrichment in both soil and sediments while A1, B, Ba and Sr are only significant in water.     

Solid-solution partitioning of arsenic （As） in the paddy soil profiles in Chengdu Plain, Southwest China

To predict the long-term behavior of arsenic(As) in soil profiles,the solid-solution partitioning of As was studied in four paddy soil profiles obtained from agricultural areas in Chengdu Plain,Southwest China.Paddy soil profile samples were collected and soil solution samples were extracted.Total As contents in soil solution and soil solid were analyzed,along with the soil solid phase properties.The As in soil solution was significantly higher in the upper layer(0—20 cm) and had a definite tendency to decrease towards 40 cm regardless of the sampling locations.When the concentration of arsenic in soil solution decreased,its content in solid phase increased.Field-based partition coefficient(K_d) for As was determined by calculating the ratio of the amount of As in the soil solid phase to the As concentration in the soil solution.K_d values varied widely in vertical samples and correlated well with soil pH,total organic carbon(TOC) and total As. The results of this study would be useful for evaluating the accumulation trends of arsenic in soil profiles and in improving the management of the agricultural soils.     

Sulfur Isotopic Characteristics of Coal in China and Sulfur Isotopic Fractionation during Coal—burning Process

The determined results of the sulfur contents and isotopic composition of coal samples from major coal mines in 15 provinces and regions of China show that the coal mined in the north of China is characterized by higher ^34S and lower sulfur content, but that in the south of China has lower ^34S and higher sulfur content.During the coal-burning process in both indrstrial and daily use of coal as fuel the released sulfur dioxide is always enriched in lighter sulfur isotope relative to the corresponding coal;the particles are always enriched in heavier sulfur isotope.The discussion on the environmental geochemical significance of the above-mentioned results also has been made.     

Occurrence and migration of hazardous trace elements in coals from Guizhou Province, China

Coals from Guizhou Province, Southwest China, attract many researchers＇ attention for their high concentrations of hazardous trace elements, sulphur and mineral components. Trace elements in coals have diverse modes of occurrence that will greatly influence their migration in the process of coal preparation. Mode of occurrence is also important in determining the partitioning during coal combustion. The coal floatation test by progressive release was used to study the migration of trace elements and mineral components in the process of froth floatation. Inductively coupled plasma mass spectrometry （ICP-MS） was used to determine the absolute concentrations of trace elements including As, Be, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Th, U, V and Zn in the parent coals and the floatation fractions. Precise determination of the mineral matter percentage in coals was obtained by low-temperature ashing. The mineral compositions in coals were quantified using Rietveld-based X-ray diffraction analysis package on low-temperature ash. Scanning electron microscope equipped with energy dispersive X-ray detector was used to provide information on the forms of occurrence of mineral components in coal. Five floatation fractions were obtained from the pulverized coal samples. The contents of trace elements and mineral components decrease from the first tailings to the last cleaned coal. The concentrations of trace elements and mineral components in parent coals and different floatation samples show that trace elements and mineral components are mainly concentrated in the first tailings samples. Nearly 60% of mineral components are enriched in the first tailings, whereas less than 1.3% remains in the cleaned coal. The ratio of sixteen trace elements concentrations in the first tailings to the corresponding concentrations in the cleaned coal ranges from 1.6 to 22.7. Quantitative mineralogical analysis results using the full-profile general structure analysis system （GSAS） showed that the main compositions of LTA include quartz, calcite, kaolinite, pyrite, chlorite, montmorillonite, illite, anatase and pyrite.     

Sulfur in Coal and Its Environmental Impact from Yanzhou Mining District,China

Sulfur is one of the havardous elements in coal The concentrations of sulfur are relatively high in coal.The major forms of sulfur in coal are pyritic,organic and sulfate.Pyritic and organic sulfur generally account for the bulk of sulfur in coal.Elemental sulfur also occurs in coal,but only in trace to minor amounts.When coals are burned,leached and washed,sulfur will be released in the form of sulfide and H2S,which then reach with O2,water and other substances to change into vitriol,and in some places it may form acid rain.And they will impact water environment,acidify the soil and do great harm to plants and human health.In this paper,on the basis of the data from the Yanzhou mining district,the distribution and concentrations of sulfur are analyzed and the existing forms of sulfur are studied.The variation of sulfur and its impact on the environments also are described when coal is used.     

Importance of measurement of rare-earth elements from the Soil Information and Monitoring System： A normalization method for detection of chromium contamination in soils

The Soil Information and Monitoring System （TIM） is an independent subsystem of the integrated Environmental Information and Monitoring System in Hungary. Based on physiographical-soil-ecological units 1202 representative observation points were selected and exactly defined by geographical coordinates using GPS. The first sampling was done in 1992. Some soil parameters are measured every year, some others every 3 years or every 6 years depending on their changeability （stability）. Toxic element, heavy metal and rare earth element contents in soil samples were determined after hot and strong acid digestion by ICP-OES equipment. The rare earth elements were measured in TIM soil samples and some of them can be found in a relatively high amount, e.g. cerium and neodymium concentration are 3-4 times higher than the very often-measured copper concentration. Close correlation was found among some of the rare earth element concentrations. The Y-Yb correlation is the strongest, its r-value is higher than 0.95. The reason of difference among the yttrium concentrations of samples is not the deviation of ICP-OES measurement that is much smaller than the difference among the individual soil samples. Similar, close correlation was obtained between the soil yttrium and chromium concentration. The amount of chromium contamination can be calculated as the distance from the Y-Cr trend line. We call this method yttrium normalization. The principle of this method is described as follows： such elements than chromium and yttrium insist in the soil in a strongly bonded form. Therefore, in a non-contaminated area there is a close correlation between the yttrium and chromium concentrations. If the measured chromium concentration in a sample is not on the Cr-Y trend line than the distance it indicates the amount of antropogenic chromium. Contamination can be detected in that case of course if the contaminant does not contain yttrium.     

Environmental Geochemistry of Heavy Metal Contaminants in Soil and Stream Sediment in Panzhihua Mining and Smelting Area,Southwestern China

Mining and smelting activities are the main causes for the increasing pollution of heavy metals in soil, Water body and stream sediment. An environmental geochemical investiga-tion was carried out in and around the Panzhihua mining and smelting area to determine the ex-tent of chemical contamination in soil and sediment. The main objective of this study was to in-vestigate the environmental geochemistry of Ti, V, Cr, Mn, Cu, Pb, Zn and As in soil andsediment and to assess the degree of pollution in the study area. The data of heavy metal con-centrations reveal that soils and sediments in the area have been slightly contaminated. Geo-chemical maps of Igeo of each heavy metal show that the contaminated sites are located in V-Ti-magnetite sloping and smelting, gangues dam. The pollution sources of the selected elementscome mainly from dusts resultant from mining activities and other three-waste-effluents. The areaneeds to be monitored regularly for trace metal, especially heavy metal enrichment.     

Heavy metal contents in soil of major towns in the east coast of Peninsular Malaysia

A total of 63 soil samples from 3 different soil profiles （urban, suburban and industrial areas） in major towns in the east coast of Peninsular Malaysia were analyzed for the total concentrations of Cu, Zn, Pb, Ni and Cr. The soil samples were subjected to acid digestion and the concentrations of total metals extracted were measured or flame atomic absorption spectrometry and inductively coupled plasma - atomic emission spectrometry. According to the result of this study, Pb and Zn concentrations in urban soils are much higher than those of industrial and suburban soils. Total concentrations of Cu and Cr in industrial soil samples are high compared to other two soil profiles and Ni concentrations in the suburban area are slightly higher those of urban and industrial soils. Since Malaysia has not yet to come up with her own soil maximum allowable limit, the heavy metal concentrations were compared with the Dutch maximum allowable limit. The results indicated that the median of heavy metals values in the three different soil profiles is still below the Dutch system limit. From the maximum allowable value obtained from the Dutch system, a contamination/pollution （C/p） index for each site was calculated for the set of these five heavy metals. An advantage of using this method is to make a differentiation between pollution （C/p〉1） and contamination （C/p〈1） status in soils as well as being able to characterize each status into 5 different categories （slight, moderate, severe, very severe and excessive）.     

Dibenzofuran Series in Terrestrial Source Rocks and Crude Oils and Applications to Oil-Source Rock Correlations in the Kuche Depression of Tarim Basin, NW China

Ten series of aromatic hydrocarbon compounds (biphenyl, naphthalene, phenanthrene, anthracene, retene, chrysene, benzoanthracene, dibenzofuran, fluorene, dibenzothiophene) isolated from seven Triassic and Jurassic lacustrine mudstone samples and three swamp coal samples, as well as five crude oil samples collected in the Kuche depression of the Tarim Basin,NW China, have been analysed by GC-MS techniques. It is found that the relative abundances of dibenzofuran series are higher in the three swamp coal samples than those in the lacustrine mudstone samples. Based on the similar relative abundances of dibenzofuran series, especially dibenzofuran compound, in the TICs of aromatic hydrocarbons, crude oils from wells SA3 (K), YTK5(E,K) and QL1 (E) are thought to have been derived predominantly from the coals of the Lower Jurassic Yangxia Formation or Middle Jurassic Kezilenuer Formation, whereas those from wells YM7 (O) and YHI (E) were derived mainly from Triassic and Jurassic lacustrine mudstones in the Kuche depression. This is the first report about how to distinguish coal-generated oils from lacustrine mudstone-generated oils in the Kuche depression in terms of the dibenzofuran series.The present paper has enlightening and directive significance for further oil-source rock correlations and oil and/or gas exploration in the Kuche depression of the Tarim Basin.     

Determination of potential hazardous elements in Can coals （Canakkale- Turkey）-I

It is known that the increasing use of coal as an energy source led to the growing environmental and health problems. But comprehensive knowledge of coal quality parameters may help to reduce some of these problems. The Canakkale-Can coalfield is located in the western part of Turkey, whose reserves are estimated at 69.3 billion tons, mainly used in the industry in the neighboring areas, specifically for the Can Thermal Power Plant. The aim of this study is to determine the coal quality parameters and examine the origin and distributions of potentially toxic trace elements in lignite which may produce environmental and health hazards in the area. The coal samples were collected from different parts of the coalfield in Can. Proximate and ultimate analyses, sulfur form analyses, X-ray powder diffraction （XRD）, inductively coupled plasma-mass spectrometry （ICP-MS）, and scanning electron microscopy （SEM） were performed on those samples to determine the geochemical profile of hazardous elements.     

Enrichment of arsenic, antimony, thallium and selenium in high-arsenic coal from Xingren County, Guizhou Province

Since 1976 high arsenic coal in Xingren County, Guizhou Province, has attracted more and more attention because of coal-burning-type arsenic poisoning, There are many studies on enrichment of arsenic in high-arsenic coal and they come from difference materials： organic matter, authigenic pyrite, epigenetic pyrite, authigenic clay mineral and epigenetic clay mineral. In this paper, fourteen samples were examined by proximate analysis. Inductively coupled plasma mass spectrometry （ICP-MS） was used to determine the trace element contents of thirty-six samples in high-arsenic coal, As was determined by instrumental neutron activation analysis （INAA） and atomic fluorescence spectrometry （AFS）. SEM-EDX was used to analyze the contents of As, Sb, Tl and Se in sample XR-8 from Xingren, Guizhou, and we analyzed the petrographic compositions of the same sample.     

Analysis of soil biogeochemical characteristics in the process of karst rocky desertification

The sampling method of karst soil is always the one used for non-karst area. However, if the samples can represent the plot, it still needs further investigation due to high degree of spatial variability of karst soil. The study results of soil from the Maolan karst virgin forest in Guizhou Province elucidated that only the surface area-weighted samples could represent plot soils in the karst ecosystem. The remediation of karst rocky desertification has currently become a national issue, but soil degradation research on rocky desertification genesis types and processes is still insufficient. Soil physical, chemical, biological characteristics and enzymes activities from plots of different rocky desertification genesis types and grades in the Cha＇eryan catchment in the Huajiang Gorge area, Guizhou, were studied. The results showed that woodcutting and land reclamation influenced soil biogeochemical characteristics, and the influence of different disturbing ways was huge. The author suggested a soil degradation index system which could illustrate the rocky desertification genesis type and extent. The degraded modes of woodcutting and reclamation sequence were different, both had no synchronism with rocky desertification grades divided by current landscape index. Only soil of serious grade degraded evidently in wood cutting sequence. On the contrary, soils of slight, medium and serious grades degraded evidently in the reclamation sequence.     

Nitrogen in Chinese coals

Three hundred and six coal samples were taken from the main coal mines of twenty-six provinces, autonomous regions, and municipalities of China. The method of Kjeldahl-Gunning Analysis was used to measure the nitrogen contents in the samples. Nitrogen in coals is principally of organic nature. A weak positive correlation between coal rank and nitrogen content is inferred in the study. The distribution of nitrogen in each geological age, coal-cumulating area and province＇s coals was studied. The contents of nitrogen in Chinese coals show approximately a normal distribution, and 90% of the values range from 0.52% to 1.41%, the average nitrogen content in Chinese coals is designated as the arithmetic mean, 0.98%.     

Transformation of organic carbon and its potential impact on lead weathering in firing range soils

Lead （Pb） is normally considered as a trace element in soils and sediments for geochemical study. However, the concentration of Pb in firing range soils is generally so high that it should be considered as a major element during the evaluation of the soil geochemical properties. Soil organic matter （SOM） has been reported as one of the major factors to expedite the corrosion of metallic lead （Pb） in acidic and organic-rich soils. The main impacts of SOM on the fate and transport of Pb in firing range soils lie in the following two aspects; （1） the complexation of organic matter with Pb, which has received lots of attention, and; （2） changes in soil redox potential due to the transformation of SOM and its subsequent impact on Pb speciation, which has rarely been investigated. Soils from 6 different firing ranges are selected for this study. These samples have been stored under a closed condition for more than 3 years. The soil moisture contents were well-retained, as all the samples were kept in closed plastic buckets. The analytical data showed that the summation of the soil total organic carbon content （TOC） and inorganic carbon contents （TIC） were consistent with soil total carbon contents （TC） measured in previous years, although the TOC and TIC contents have changed respectively after years of storage. In general, it is observed that the soil TOC decreased against an increase of TIC. The mass balance on such a transformation suggested a major conversion of organic carbon （Corg） to inorganic carbon （CO3^2-） in the stored soils.     

Distribution Characteristics of Sulfur and the Main Harmful Trace Elements in China’s Coal

To promote the rational development and use of clean coal resources in China, data on the regional and age distribution of sulfur, arsenic and other harmful elements in Chinese coal was broadly collected, tested for content, and analyzed. Coal in northwestern China is characterized by low to extremely low levels of sulfur; the coal of the Taiyuan Formation in northern China mainly has high-sulfur content; that of the Shanxi Formation is mainly characterized by low sulfur coal; and the Late Permian coal in southern China has overall higher sulfur content; other regions have low sulfur coal. The average content of harmful trace elements in the bulk of China＇s coal is similar to the corresponding content in the coal of the North America and the rest of the world, whereas the content of various elements （Hg, Sb and Se） is different in magnitude to the corresponding percentage in the crust. The average content of the elements Cr, Se, Co, Be, U, Br in Late Permian coal in S China ranks first in the country whereas the average content of Hg and CI in the coals of Late Carboniferous to Early Permian age in N China are the highest. The average content of Mn in Early and Middle Jurassic coal is higher in NW China. The high content of harmful elements in some coal should cause particular concern both in the development and utilization of coal.     

Environmental impacts of the abandoned mercury mine in Podljubelj, Slovenia

The Podljubelj mercury mine lies in the NW part of Slovenia. The ore is of hydrothermal-vein type. The ore deposit was exploited between the years 1557 and 1902. Total production of the mine was 110000 tons of ore （360 tons of Hg）. A smelter located close to the mine had been in operation since 1855. The waste material from the mine and the smelter was dumped in close vicinity of the mine. Total quantity of the waste has been estimated at 170000 tons. In order to establish environmental impacts, soil and stream sediment samples were investigated. Soil samples were collected at two different depths （horizons A and B） in a 100 m grid within an 88 ha area. In the vast area also 11 samples of stream sediments were considered. Heavy metals were determined by means of cold vapor atomic absorption spectrometry CV-AAS after aqua regia digestion. Based on the chemical analyses of samples, the estimated mercury mean for soils is 3.67 mg/kg （0.35-244 mg/kg） for horizon A and 1.39 mg/kg （0.17-71.7 mg/kg） for horizon B. The estimated mercury mean for stream sediments is 0.64 mg/kg （0.065-1.36 mg/kg）. The concentrations of mercury in soils generally decrease with depth and distance from the mine. The highest content of Hg was determined in a sample taken in the immediate vicinity of the smelter （719 mg/kg）. The results have shown that on the 9 ha of the study area, the contents of Hg in soils exceeded the officially set limit value for soils （10 mg/kg）. High contents of Hg in soil around the abandoned smelter are a consequence of former atmospheric emissions and technological losses. High contents of Hg were also found in the mine and smelter waste dump. At the edges of the study area and in the samples of stream sediments, Hg concentrations are low.     

Quantification of displacement and particle crushing around a penetrometer tip

Particle crushing occurs near the tip of a penetrometer and influences the development of the tip resistance.To study particle crushing near a penetrometer tip,a cone penetrometer was monotonically jacked and then load-tested in medium dense and dense silica sand samples prepared in a halfcylindrical calibration chamber with viewing windows.During the tests,images of the advancing penetrometer and the surrounding soil were taken using digital cameras and analyzed to obtain the displacement and strain fields around the penetrometer using the Digital Image Correlation(DIC)technique.Subsequently,soil samples were collected near the tip of the penetrometer using a novel agarimpregnation technique and digitized using an X-ray microscope.The digitized samples were analyzed to reconstruct the three-dimensional models of individual particles,generating the gradation and relative breakage parameters of the sand around the cone penetrometer.     

Fluoride exposure in the endemic fluorosis area of Guizhou, China

The dental and skeletal fluorosis is highly prevalent in Zhijin, Guizhou, especially at Hualuo Village, Hehua Village and Majiazhuang Village. The contents of fluorine in coal, clay used for coal combustion, mixed fuel of coal and clay, corn, and chili from households of the three villages were determined by the pyrohydrolysis-fluorine ion-selective electrode method. The average contents of fluorine in the above samples respectively are 237 mg/g, 2262 mg/g, 828 mg/g, 1419 mg/g, and 110 mg/g. The clay used for coal combustions is the main fluorine source of endemic fluorosis and the inferior coal and weathered coal are the secondary source of fluorine. During the combustion of mixed fuel of coal and clay, about eighty percent of fluorine was volatilized, approximately two thirds of which was from the clay and the other one third from the coal. The occurrence of fluorine in clay used for coal combustion is closely related to apatite and hornblende. The contents of fluorine in corn and chili, dried by coal-clay mixed fuel are about 1400 and 73 times higher than the permitted level of fluorine in foods according to the Chinese Standard. It is worth paying attention to the high-fluorine indoor surroundings, such as coal, clay, corn, and chili, particularly ash from boiler bottom with the fluorine content of 15738 μg/g. Besides the technologies of fluorine fixation during the combustion,