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1.
Organic geochemistry and comparisons of characteristics of the organic matter in wall rocks of the ore-controlling strata and ores of the Lower Jurassic Songling black shale formation and the related Songxi silver-antimony deposit of northeastern Guangdong have been studied in this paper.The results show that the Lower Jurassic Songling shale formation is a suite of biologic-rich and organic-rich ore-bearing marine sedimentary rocks.Micro-components of the organic matter in the Songling black shale formation consists primarily of algae,amorphous marine kerogen,solid bitument,and pyrobitument.The thermal evolution of organic matter is at the over-maturity stage.There is a general positive correlation between total organic carbon(CO)and metallogenetic elements such as Ag and Sb in the black shale formation.Organic matter in the host rocks in the Songxi ore deposit played a role in controlling the silver-antimony depositing environment during the forming process of the black shale ore-bearing formation.In the absence of vitrinite,the relative level of thermal maturity calculated by solid bitument reflectance indicates that the ore-forming temperatute of the Songxi silver-antimony deposit was about 150-170℃,which was considered as an epithermally reworked ore deposit.The roles of organic matter in the formation of the Sonxi ore deposit are a primitive accumulation of the metallogenetic elements(Ag,Sb) in the sea-water cycle system for ore source and a concentration of metals by ion exchange of chelation as well as reductionn of the oxidzed metals.  相似文献   

2.
Although inorganic species are predominant in natural systems, but there are many kinds of organoarsenic species such as methylated and phenylated arsenic compounds. Phenylarsonic acid （PA） is a degradation product of organoarsenics used for chemical warfare agents, which has been detected in well water at the disposal site of the agents in Japan. There are few reports studying behavior of PA in soil. In this study, PA was adsorbed onto ferrihydrite and its chemical forms were determined using high performance liquid chromatography connected to inductivity-coupled plasma mass spectrometry （HPLC-ICP-MS）. 100 mg/kg of PA was mixed with 0.03 g of 2-line ferrihydrite. For each suspension, pH was adjusted by HNO3 or NaOH. Each sample was incubated for more than 19 hours and the final pH was measured. After filtration, the chemical form of arsenic in the filtrate was measured using HPLC-ICP-MS. In addition, ferrihydrite separated by filtration was dissolved by 3 ml of 0.5 M HCI and the arsenic species in the solution was detected by HPLC-ICP-MS （column： Tosoh TSKgel SuperlC-AP, eluent： 0.01 M HNO3）. It was verified that PA is not degraded by heating in 0.5 M HCl solution. At pH 3.1, any arsenic compounds were not detected from the solution, because almost all arsenic species were adsorbed onto ferrihydrite at lower pH. At pH= 12, however, 7%-10% of inorganic arsenic was detected in the solution. In solid phase, there are some problems to determine the precise ratio of inorganic and organic species. When the solution includes Fe ion at 0.01 M level, the retention time of arsenic species drifted compared to those in standard solution, which makes it difficult to determine precisely the arsenic species adsorbed on ferrihydrite. Therefore, more study is needed to determine the ratio of inorganic and organic species in the system.  相似文献   

3.
Mineral-bituminous matrix(MBM) makes up a major part of source rocks,but its potential in hydrocarbon generation is uncertain,Mineral and organic (Maceral and kerogen) compositions,organic maturity and fluorescence of MBM are studied based on source rock samples from eastern Jiuquan(Jiudong)Basin.The results show that MBM is dominated by inorganic minerals and among the small percentage of organic components those of secondary origins are predominant over the primary species.This strongly indicates that the significance of MBM in hydrocarbon generation is limited.  相似文献   

4.
Systematic （monthly） observations of changes in the components of trophic status in the pelagic zone of Baikal were carried out during years of spring blooms of almost pure cultures： Gymnodinium （1965）, Aulocoseira bai-calensis （1968）, Synedra acus （1969）, Nitzschia acicularis （1984 and 1987）, picocyanobacteria （2004-2005）. The research period coincided with various anthropogenic impacts on Baikal ecosystem： （1） the period of the natural state of the lake （until 1969）; （2） the period of weak anthropogenic impact （until 1985）; and （3） the period of acute anthropogenic impact. In the third period the following was found in the deep-water part of the lake： the episodic appearance of ammonium and nitrite nitrogen; change in the components of suspended matter （SM）; disturbed patterns of seasonal changes in SM content, chlorophyll-a, organic forms of carbon, nitrogen and phosphorus; the average annual concentrations of suspended organic carbon, nitrogen and phosphorus have increased considerably; the vertical distribution pattern of minerals and organic forms of nitrogen and phosphorus have been disturbed; finally, an observed inverse correlation between winter nitrogen content and the spring concentration of chlorophyll-a （1986-1989） would indicate the presence of toxins in the lake. This led to the study of POPs in Baikal and the Baikal region. Investigations undertaken during 2004-2005 in the pelagic coastal zones of the lake indicated the presence of toxic pollutants in southern Baikal （the correlation between winter nitrogen content and spring concentration of chlorophyll-a is inverse and equals 0.99 and 1.00 respectively）. Toxicants that enter the lake during the iced-over period mainly enter the trophogenic layer, as wastewaters are warmer than the lake waters, depress the development of endemic spring diatomic algae and lead to a rise in the trophic status.  相似文献   

5.
With the rapid development of industrialization and urbanization in the Pearl River Delta region, organic as well as inorganic pollution is becoming a major environmental concern. Urban deposits including road dusts, corresponding gully sediments and topsoils proved to be useful tools for assessing the level and distribution of contaminants in metropolitan areas. Most of the previous studies utilizing urban deposits, however, focused on inorganic pollutants, while data on organic pollutants are rare. In this study, therefore, the organic pollutants in urban deposits of Hong Kong and Guangzhou were systematically investigated in terms of their abundance, composition and distribution. The road dusts, gully sediments and vehicular tunnel dusts as well as soils from different urban locations with variable traffic volumes （less than 1000 to more than 75000 AADT） were examined. The results indicated that vehicle-emitted particles were the major source of organic pollutants, while the contributions from background soils were very limited. Surprisingly, the soil in a remote island of Hong Kong with no vehicular traffic has also shown signs of pollution from vehicular particles likely through dry-wet atmospheric deposits. In general, the characteristics of organic pollutants in urban dusts from both cities are comparable although there were also some significant differences. For example, the amount of extractable organic matter in urban deposits of Hong Kong was significantly higher than that of Guangzhou. Differences in their extractable asphaltene contents not only reflected the differences in quality and types and fuels used in these cities, but also sample residence times, and thus different extents of weathering processes.  相似文献   

6.
Microorganic pollutants such as polycylic aromatic hydrocarbons （PAHs）, organochlorine pesticides （OCPs）, polychlorinated biphenyls （PCBs） and total petroleum hydrocarbons （TPHs） are known to be present in urban ambient air. These organic compounds are prone to atmospheric transport and deposition over long distances, thus enabling them to accumulate even in regions remote from their sources. Deposition from the atmosphere can be via direct deposition and exchange with crops that may be directly or indirectly ingested by humans. It can also take place via wet and dry deposition and air-water exchange. Following their deposition, these microorganic pollutants tend to accumulate in soils, sediments and in human and ecological food chains. There are many reports in the literature on the atmospheric concentrations of microorganic pollutants, but there are few reports and data in Asia. This study was performed in Singapore to determine the relative amounts of persistent organic pollutants and TPHs in ambient aerosols. One of the important sources of these organic compounds in Southeast Asia is thought to be biomass burning （vegetation fires）. Hence, air sampling was conducted during both smoke haze and non-haze periods. The data obtained from this study will be presented and discussed.  相似文献   

7.
《中国地球化学学报》2006,25(B08):68-68
Honey is valuable food for mankind since the ancient times. It was the only sweetener till the start of the industrial sugar mass production. As honey plays an important role in our nutrition and its positive effects on health is well known, it is very important to study the nutritional properties and the origin of different honey samples. The usually determined quality parameters of honey： pH values, water content, sugar content, acidity, HMF content, enzyme activity, pollen content, amino acid content, ash content, etc. It is also important to know the content of the organic contaminants in honey. A short time ago there were some quality problems with Hungarian and Greek honey in the European Union. A toxic material （para-dichlorobensene） was found in honey originated from Greece. The amount was higher than the allowable limit in the EU. Therefore, it is necessary to build up a good and applicable traceability system for honey. During the past few years the traceability concept has become increasingly familiar in many sectors of the food industry. Traceability is an essential tool for ensuring both production and product quality. The opportunity to connect traceability with the whole documentation and control system represents an effective means for boosting the consumer＇s perception of a food＇s safety and quality. In our work we have done, which quality parameters can be used for a good identification system.  相似文献   

8.
The experiment was conducted to determine the organic carbon concentrations of black soils by using density fractionation and wet-sieving of aggregates into five size fractions. Soil samples （0-20 cm layer） were collected from the following experiment sites （National Field Research Station of Agro-ecosystem in Hailun, Northeast of China）： （1） grassland （GL）, formerly cropped, and but fallowed in 1985 with Leymus chinesis as the dominant species; （2） bareland （BL）, like grassland, fallowed in 1985, but grasses were eliminated periodically during the plant growth stages; （3） cropland, three treatments in a long-term site experiment established in 1993 were selected, including no fertilizer applied （NF）, nitrogen and phosphorus fertilizers applied （NP）, and NP fertilizer amended with organic materials （NPOM）. The results showed that the total organic carbon （TOC） concentrations within five experiment sites differed significantly at P〈0.01. The natural ecosystem subjected to human disturbance or transferred into cropland resulted in loss of TOC, however, TOC concentrations increased significantly with chemical fertilizer plus organic manure incorporated into cropland. The OC concentrations in the free light fraction （free-LF） and heavy fraction （HF） had significant correlations with those of TOC in the whole soil at P〈0.01, which indicated that the accumulation of free-LF and HF was very important for the net increase in the TOC. In GL more than 90% of the aggregate separates was larger than 0.25 mm, in which aggregates larger than 2 mm accounted for 44%, as a result of physical enmeshing of fine roots.  相似文献   

9.
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.  相似文献   

10.
Soils contain about twice the amount of carbon presented in the atmosphere, so a small change in the soil carbon will influence atmospheric chemistry and heat balance. The soil carbon ultimately exchanged with the atmospheric CO2 as soil CO2, which mainly exists at the depth of 0-20 cm. The transport of soil CO2 is affected by the sources of soil CO2. Thus, separation of the contributions of sources of soil CO2 is a fundamental need to understand and predict implications of environmental change on soil carbon cycling and sequestration. It is a complicated task, so that a number of different methodological approaches such as component integration, root removal, and gap analyses have been developed. However, these methods could not avoid changing soil characteristics such as air-filled porosity, soil temperature and soil water contents. Consequently, fractional contributions of respiration of living root and decomposition of soil organic matter to the total soil CO2 cannot be estimated correctly. In this study, based on mass balance theory of both concentrations and δ^13C of soil CO2, a trenching method with a stable-isotope technique was used to determine both soil CO2 sources at the depth of 3-13 cm in a Japanese larch forest area during 30 May to 7 October 2005 and fractional contributions of these sources. Experimental results showed that the amount of atmospheric CO2 invaded the soil air was not significantly variable while its percent rate in the total soil CO2 had significantly temporal variations with the lower values between 5 August and 1 September. The litter-layer decomposition was very small. The soil CO2 derived from the respiration of living root and the decomposition of soil organic matter showed significantly temporal variations with increase from 30 May to 5 Aug. and decrease from 1 September to 7 October, 2005; and it accounted for 82%-98% of the total soil CO2 in which the respiration of living root was in the range from 32% to 62%.  相似文献   

11.
A 63-cm sediment core documents that the concentrations of nutrients in sediment, such as organic carbon, nitrogen and phosphorous, continually increased during the last century in Longgan Lake, middle reaches of the Yangtze River, China. C/N ratio and δ^13Corg revealed that organic matter in the sediment derived mainly from aquatic and terrestrial sources is a minor contributor. Excess phosphorous is related to human activities marked by utilization of phosphoric fertilizers since 1952 A.D. The increase of δ^13Corg towards the sediment surface, together with increasing of OC and N accumulation, indicated the elevation of lake primary productivity due to excess phosphorous loading caused by utilization of phosphoric fertilizer. The decrease of δ^15N during the primary productivity elevation process, especially after 1952, can be attributed to the discharged of nitrogen with lower δ^15N into the lake.  相似文献   

12.
《中国地球化学学报》2006,25(B08):188-188
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13.
Based on the analysis of siderite distribution,occurrence,chemical compositionk,structureal characteristics,carbon-oxygen isotopic characteristics and relationship between siderite and hematite,this paper presents a systematic study of siderite in the region studied.suggesting that the siderite in the Xuanlong area genetically resulted from organically reduced primary hematite during the diagenesis.The ferric and ferrous relations directly depend on organic contents.In the presence of organic matter ferrous iron can be converted to ferric iron through or ganic reduction.The above conclusion has also been proved by organic geochemistry.data.  相似文献   

14.
Natural organic matter （NOM） is an important ingredient in soil which can improve physical, chemical, and biological properties of soils and nutrient supplies. In this study, we investigated the spectral features and potential availability of phosphorus （P） in the IHSS Elliott Soil humic acid standard （EHa）, Elliott soil fulvic acid standard Ⅱ （EFa）, Waskish peat humic acid reference （WHa）, and Waskish peat fulvic acid reference （WFa） by fluorescence spectroscopy, FT-IR, solution 31P NMR, 3-phytase incubation and UV irradiation. We observed more similar spectral features between EHa and EFa as well as between WHa and WFa than between the two humic acids or two fulvic acids themselves. Phosphorus in WHa and WFa was mainly present in the orthophosphate form. However, only about 5% was water soluble. After treatment by both UV irradiation and enzymatic hydrolysis, soluble orthophosphate increased to 17% of WHa P, and 10%o of WFa P. Thus, it appears that a large portion of P in Waskish peat humic substances was not labile for plant uptake. On the other hand, both orthophosphate and organic phosphate were present in EHa and EFa. Treatment by both UV irradiation and enzymatic hydrolysis increased soluble orthophosphate to 67% of EHa P and 52% of EFa P, indicating that more P in Elliott soil humic substances was potentially bioavailable. Our results demonstrated that source （soil vs. peat） was a more important factor than organic matter fraction （humic acid vs. fulvic acid） with respect to the forms and lability of P in these humic substances.  相似文献   

15.
This paper discussed the stabilities of heavy metals in soils treated with red mud. Soil has been polluted by heavy metals more and more seriously during recent several decades, and they are harmful to mankind and animals. The current tendency is to develop in-situ technique by using industrial processing waste as additives to stabilized heavy metals to minimize the disturbance of contaminated soils. Soil samples were collected from the Niujiaotang mining area, Guizhou Province, southwestern China. They were farmed soils polluted weakly by fly ash （QBT） and polluted badly by waste water （BXT） from smelter, respectively. One of the red mud samples （BRM） was collected from Bayer process and the other （CRM） from confederate process in the Alumina Plant of Guizhou. Free metal ion concentrations were analyzed with Donnan Membrane Technique and predicted with ECOSAT. The concentrations of free heavy metal ions in QBT increased after appending CRM, but decreased when adding BRM. The more the red mud was added, the higher the concentration would be, and the free concentrations of nickel and cadmium ions would vary more greatly than those of copper and zinc ions. When appending red muds into BXT, the free concentrations of copper and zinc ions varied little. While those of free nickel and cadmium decreased obviously at the ratio of 2.00%. The variation of the concentration was still biggish after appending BRM at the ratio of 0.50%, but smaller than that of 2.00%. The concentrations of free cadmium ions increased after adding CRM at the ratio of 0.50%. All experimental processes were modeled through ECOSAT. The predicted and measured results were consistent, except for zinc. Contributions of soil sorbents to the heavy metal adsorptions were also modeled through ECOSAT. The sorbents in soil included soil organic matter, iron hydroxides, clay and the Donnan gel of soil organic matter. Compared to the soils without red muds, no matter what kind of red mud and how much was added in soil, the contributions changed slightly.  相似文献   

16.
Biomarker Compounds as Indicators of Paleoenvironments   总被引：2，自引：0，他引：2  
In an attempt to assess the paleoenvironments of terrestrial sediments,some twenty-two representa-tive Chinese non-marine sediment samples were studied using the molecular organic geochemistry method.The sediment samples stuied include oilshale,shale,mudstone and glauber salt from Tertiary to Cretaceous in age.Judging from geological/geochemical data and paleosalinity data,the samples studied are of lacustrine sedimentary origin and can be divided into three different types:fresh water,brackish and saline/hypersaline lake sediments.The aliphatic fractions were separated from the extracts of the samples and analysed by means of GC and GC/MS instruments,giving a number of parameters such as relative abundances of alkanes and cycloalkanes as shown in the mass chromatograms.  相似文献   

17.
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.  相似文献   

18.
Soils are the largest carbon reservoir in the terrestrial system. Soils contain about three times more carbon than vegetation and twice as much as that present in the atmosphere. Soil organic matter （SOM） is very complex in composition and structure, formed of heterogeneous substances and generally associated with minerals in soils. SOM is classified as labile and stable fractions on the basis of residence time, determined not only by the chemical composition of SOM, but also by types of protection or bonds within soils. The stable carbon fraction is protected either physically or chemically. To understand the process of SOM stabilization, physicochemical properties of organic-mineral complexes were determined by Fourier transformed infrared （FTIR） with attenuated total reflectance （ATR） and diffuse reflectance （DRIFT）, atomic force microscopy （AFM）, and nuclear magnetic spectroscopy （NMR）. Humic acids and carboxylic acids with relatively short carbon chains were used as sorbates, and goethite, kaolinite, and montmorillonite as adsorbents. Humic acid was fractionated during adsorption on the minerals, which was highly influenced by the characteristics of minerals. For instance, long-chain aliphatic carbon was likely to be adsorbed onto the surface of kaolinite and montmorillonite, while goethite surface attracted carboxylic functional groups of humic acid.  相似文献   

19.
The characters of organic matter in rocks and ores in the Fankou and Dabaoshan deposits are systematically studied with regard to their implications for mineralization.The results show that kerogens in this area faaa mainly into the plutonism field in Van Krevelen‘s diagram.Reflectivity of the organic substance was measured to be 3.06%(Fankou)and 1.67%(Dabaoshan),corresponding to the paleo-geotemperatures of 232℃ and 184℃ respectively.The same types of porphyrins and hydrocarbons were recognized in the rocks and ores and hydrocarbon-bearing inclusions are widespread in quartz and calcite,particularly in Dabaoshan,It is thought that the orgain matter must have played a critical role in diagenesis and metallization in these deposits and that the hydrothermal solution was most likely to be the type of water-oil hot brine.  相似文献   

20.
Organic matter from the Lower Paleozoic strata on the northern margin of the Tarim Basin of China contains abundant alkylcyclohexanes.The n-alkylcyclohexanes show the even(C16-C20) and odd (C17-C21) carbon number predominance and smooth distribution,and the methyl-n-alkylcycolhexanes the odd carbon number predominance(C17-C21) and smooth distribution,which may be related to their depositional environments and organic precursors.There are some differences in carbon number distribution between the two series of monocyclic alkanes and the n-alkanes marked by smooth distribution.The genetic relationship between the three series of compounds needs to be further studied.  相似文献   

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