共查询到20条相似文献,搜索用时 15 毫秒
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厌氧生物法处理高浓度酸性硫酸盐废水研究 总被引:1,自引:0,他引:1
以厌氧移动床生物膜反应器处理高浓度酸性硫酸盐废水,考察了生长因子B对体系pH缓冲能力和SO4^2-去除率影响。实验证明,加入生长因子后,可使进水pH值从6.80降到3.08,出水pH稳定在6.78±0.5,此pH下SO4^2-去除率比单一葡萄糖为碳源提高5.72倍。在半连续试验确定的体系最佳运行参数下连续运行试验,SO4^2-、CODCr去除率分别从85.17%、74.05%增至95.66%和88.56%,148 d负荷试验后,进水SO4^2-浓度从500 mg/L增加至2 876 mg/L时,出水SO4^2-浓度均在238.42 mg/L以下,SO4^2-的去除率稳定在90%以上,处理SO4^2-浓度最高可达3 580 mg/L。该体系在加入生长因后,可处理高浓度的酸性硫酸盐废水。 相似文献
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Molecular biogeochemistry of sulfate reduction, methanogenesis and the anaerobic oxidation of methane at Gulf of Mexico cold seeps 总被引:3,自引:0,他引:3
The anaerobic oxidation of methane in aquatic environments is a globally significant sink for a potent greenhouse gas. Significant gaps remain in our understanding of the anaerobic oxidation of methane because data describing the distribution and abundance of putative anaerobic methanotrophs in relation to rates and patterns of anaerobic oxidation of methane activity are rare. An integrated biogeochemical, molecular ecological and organic geochemical approach was used to elucidate interactions between the anaerobic oxidation of methane, methanogenesis, and sulfate reduction in sediments from two cold seep habitats (one brine site, the other a gas hydrate site) along the continental slope in the Northern Gulf of Mexico. The results indicate decoupling of sulfate reduction from anaerobic oxidation of methane and the contemporaneous occurrence of methane production and consumption at both sites. Phylogenetic and organic geochemical evidence indicate that microbial groups previously suggested to be involved in anaerobic oxidation of methane coupled to sulfate reduction were present and active. The distribution and isotopic composition of lipid biomarkers correlated with microbial distributions, although concrete assignment of microbial function based on biomarker profiles was complicated given the observed overlap of competing microbial processes. Contemporaneous activity of anaerobic oxidation of methane and bicarbonate-based methanogenesis, the distribution of methane-oxidizing microorganisms, and lipid biomarker data suggest that the same microorganisms may be involved in both processes. 相似文献
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Kent Brooks 《Geology Today》2020,36(5):192-197
Lithium is a critical element in modern technology, and lithium minerals will play a key role in the fight against climate change. However, the demand for lithium-ion batteries is dependent on an expanding supply of primary resources. Lithium occurs in limited amounts on the Earth in a surprising diversity of mineral species, from pyroxenes to amphiboles, phyllosilicates to phosphates. This article examines the principal mineral groups likely to be a target for future exploitation. 相似文献
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The anaerobic degradation of organic matter in Danish coastal sediments: iron reduction, manganese reduction, and sulfate reduction 总被引:27,自引:0,他引:27
We used a combination of porewater and solid phase analysis, as well as a series of sediment incubations, to quantify organic carbon oxidation by dissimilatory Fe reduction, Mn reduction, and sulfate reduction, in sediments from the Skagerrak (located off the northeast coast of Jutland, Denmark). In the deep portion of the basin, surface Mn enrichments reached 3.5 wt%, and Mn reduction was the only important anaerobic carbon oxidation process in the upper 10 cm of the sediment. In the less Mn-rich sediments from intermediate depths in the basin, Fe reduction ranged from somewhat less, to far more important than sulfate reduction. Most of the Mn reduction in these sediments may have been coupled to the oxidation of acid volatile sulfides (AVS), rather than to dissimilatory reduction. High rates of metal oxide reduction at all sites were driven by active recycling of both Fe and Mn, encouraged by bioturbation. Recycling was so rapid that the residence time of Fe and Mn oxides, with respect to reduction, ranged from 70-250 days. These results require that, on average, an atom of Fe or Mn is oxidized and reduced between 100-300 times before ultimate burial into the sediment. We observed that dissolved Mn2+ was completely removed onto fully oxidized Mn oxides until the oxidation level of the oxides was reduced to about 3.8, presumably reflecting the saturation by Mn2+ of highly reactive surface adsorption sites. Fully oxidized Mn oxides in sediments, then, may act as a cap preventing Mn2+ escape. We speculate that in shallow sediments of the Skagerrak, surface Mn oxides are present in a somewhat reduced oxidation level (< 3.8) allowing Mn2+ to escape, and perhaps providing the Mn2+ which enriches sediments of the deep basin. 相似文献
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According to the rules accepted by the Commission on New Minerals, Nomenclature and Classification, International Mineralogical Association, the definition of a new mineral species within the eudialyte group should be based on the general crystal chemical principle of the predominance of a new element at one or several key sites. To date, 25 minerals of the eudialyte group have been approved in line with this recommendation. Additionally, 50 samples (including potential new species of the eudialyte group) have been investigated using IR spectroscopy and X-ray diffraction. The new data require the modification and complementation of the current systematics of the eudialyte group. The eudialyte-type structures contain unique fragments that involve species-forming key sites. The crystal chemical classification that develops in this study is based on the hierarchical principle that takes into account the following features (listed in order of their lowering classification rank):
- simple or modular character of the crystal structure and value of c parameter (about 30 and 60 Å for 12- and 24-layer minerals, respectively)
- symmetry determined by cation ordering in the octahedral ring, i.e., the possibility of dividing site M(1) into M(1a) and M(1b)
- the distribution of different components into five M(2) square-based sites
- the water content (subdivision of the eudialyte-group minerals into low-and high-hydrous species with Na > (H2O + H3O) and Na < (H2O + H3O), respectively.
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硅酸盐-盐(硫酸盐)流体不混溶:蒙古南部Mushugai-Khuduk含火成碳酸岩杂岩体矿物中的熔体包裹体研究 总被引:1,自引:0,他引:1
IrinaA.Andreeva Vyacheslav I.Kovalenko Vladimir B.Naumov 《岩石学报》2007,23(1):73-82
Crystalline and melt inclusions were studied in garnet,diopside,potassium feldspar,and sphene from the garnet syenite porphyry of the carbonatite-bearing complex Mushugai-Khuduk,southern Mongolia.Phlogopite,clinopyroxene,albite,potassium feldspar,spheric,wollastonite,magnetite,Ca and Sr sulfates,fluorite,and apatite were identified among the crystalline inclusions. The melt inclusions were homogenized at 1010~1080℃and analyzed on an electron microprobe.Silicate,salt,and combined silicate- salt melt inclusions were found.Silicate melts show considerable variations in SiO_2 concentration(56 to 66wt% ),high Na_2O K_2O (up to 17wt% ),and elevated Zr,F,and C1 contents.In terms of bulk rock chemistry,the silicate melts are alkali syenites.During thermometric experiments,salt melt inclusions quenched into homogeneous glasses of predominantly sulfate compositions containing no more than 1.3wt% SiO_2.These melts are enriched in alkalis,Ba,Sr,P,F,and C1.The investigation of the silicate and salt melt inclusions in minerals of the garnet syenite porphyries indicate that these rocks were formed under influence of the processes of crystallization differentiation and magma separation into immiscible silicate and salt(sulfate)liquids. 相似文献
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The simple theory of equation of state recently developed by Kumar is used to investigate the temperature and pressure dependence of elastic moduli of MgO. The results are found to present good agreement with the experimental data. It is concluded that the Kumar formulation is far better than the Suzuki theory of thermal expansivity, and the Shanker formulation is not a new relation. 相似文献
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Rosascoet al. (1975), reported the first successful application of laser-excited Raman spectroscopy for the identification and nondestructive partial analysis of individual solid, liquid, and gaseous phases in selected fluid inclusions. We report here the results of the application of a new instrument, based on back-scattering, that eliminates many of the previous stringent sample limitations and hence greatly expands the range of applicability of Raman spectroscopy to fluid inclusions.Fluid inclusions in many porphyry copper deposits contain 5–10 μm ‘daughter’ crystals thought to be anhydrite but too small for identification by the previous Raman technique. Using the new instrument, we have verified that such daughter crystals in quartz from Bingham, Utah, are anhydrite. They may form by leakage of hydrogen causing internal autooxidation of sulfide ion. Daughter crystals were also examined in apatite (Durango, Mexico) and emerald (Muzo, Colombia).Valid analyses of sulfur species in solution in small fluid inclusions from ore deposits would be valuable, but are generally impossible by conventional methods. We present a calibration procedure for analyses for SO42? in such inclusions from Bingham, Utah (12,000 ± 4000 ppm) and Creede, Colo. (probably < 500 ppm). A fetid Brazilian quartz, originally thought to contain liquid H2S, is shown to contain only HS? in major amounts. 相似文献
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Transformational changes of clay minerals, zeolites and silica minerals during diagenesis 总被引:1,自引:0,他引:1
Diagenetic transformation of clay minerals, zeolites and silica minerals in Cretaceous and Tertiary argillaceous rocks from deeply drilled wells in Japan were studied. Transformations of these minerals during diagenesis were as follows: in clay minerals, montmorillonite → montmorillonite-illite mixed-layer mineral → illite; in zeolites, volcanic glass → clinoptilolite → heulandite and/or analcite → laumontite and/or albite; in silica minerals, amorphous silica → low-cristobalite → low-quartz. Maximum overburden pressures and geothermal temperatures corresponding to these transformations in each well studied were calculated. For clay minerals, a pressure of approximately 900 kg cm?2 and a temperature of about 100°C are necessary for the transformation from montmorillonite to mixed-layer mineral and 920 kg cm?2 and 140°C for mixed-layer mineral to illite. Transformation from kaolinite to other minerals requires much higher pressures and temperatures than from montmorillonite to mixed-layer mineral. For zeolites, 330 kg cm?2 and 60°C are required for the transformation from volcanic glass to clinoptilolite, 860 kg cm?2 and 120°C for clinoptilolite to heulandite and/or analcite, and 930 kg cm?2 and 140°C for heulandite and/or analcite to laumontite and/or albite. For silica minerals, 250 kg cm?2 and 50°C are necessary for the transformation from amorphous silica to low-cristobalite and 660 kg cm?2 and 70°C for low-cristobalite to low-quartz. Based on these diagenetic mineral transformations, seven mineral zones are recognized in argillaceous sediments. On the other hand, from the porosity studies of argillaceous sediments in Japan, the process of diagenesis is classified into the following three stages. The early compaction stage is marked by shallow burial and viscous rocks with more than 30% porosity. The late compaction stage is characterized by intermediate burial and plastic rocks with 30-10% porosities. The transformation stage is marked by deep burial and elastic rocks with less than 10% porosity. 相似文献
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Marshall W. Bowles 《Geochimica et cosmochimica acta》2011,75(2):500-519
We investigated coupling between sulfate reduction (SR) and anaerobic oxidation of methane (AOM) by quantifying pore water geochemical profiles, determining rates of microbial processes, and examining microbial community structure at two sites within Mississippi Canyon lease block 118 (MC118) in the Northern Gulf of Mexico. Sediments from the northwest seep contained high concentrations of methane while sediments from the southwest seep contained methane, gaseous n-alkanes and liquid hydrocarbons and had abundant surficial accumulations of gas hydrate. Volumetric (21.5 μmol cm−3 day−1) and integrated (1429 mmol m−2 day−1) rates of SR at MC118 in ex situ incubations are the highest reported thus far for seafloor environments. AOM rates were small in comparison, with volumetric rates ranging from 0.1 to 12.6 nmol cm−3 day−1. Diffusion cannot adequately supply the sulfate required to support these high SR rates so additional mechanisms, possibly biological sulfide oxidation and/or downward advection, play important roles in supplying sulfate at these sites. The microbial communities at MC118 included sulfate-reducing bacteria phylogenetically associated with Desulfobacterium anilini, which is capable of complex hydrocarbon degradation. Despite low AOM rates, the majority of archaea identified were phylogenetically related to previously described methane oxidizing archaea. To evaluate whether weak coupling between SR and AOM occurs in habitats lacking the complex hydrocarbon milieu present at MC118, we compiled available SR and AOM rates and found that the global median ratio of SR to AOM was 10.7:1 rather than the expected 1:1. The global median integrated AOM rate was used to refine global estimates for AOM rates at cold seeps; these new estimates are only 5% of the previous estimate. 相似文献
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Alan Bruce Thompson 《Contributions to Mineralogy and Petrology》1974,48(2):123-136
The discrepancy between the tabulated Gibbs Energies of Formation for Al2SiO5 and corundum relative to muscovite and kaolinite is considered to lie principally with the latter two minerals. New values for heat of formation of gibbsite [Gbs] will affect the tabulated H
f
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, G
f(298,1)
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for the other aluminous minerals which are referred to gibbsite as calorimetric aluminum reference. Gibbs Energy Difference Functions, calculated from phase equilibria in the system CaO-Al2O3-SiO2-(H2O-CO2), can be used to estimate consistent H
f
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, G
f(298,1)
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values for aluminous minerals. A self consistent data set is presented referred to G
f(298,1)
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[Corundum]=–378.08 kcal mol–1. Two independent values for G
f(298,1)
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[Anorthite]=–961.52 and –960.29 kcal, from a recalculation of the H
f
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[Anor] based upon the revised H
f(298,1)
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[Gbs]=–309.325 kcal mol–1 and from measurement of silica activity on the anorthite-saturated part of the CaO-Al2O3-SiO2 liquidus, respectively, are considered to show the magnitude of the discrepancy and are used in the calculations. 相似文献
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D. Taylor 《Contributions to Mineralogy and Petrology》1967,16(2):172-188
The results of a study of the chemical composition, cell parameters, density and refractive index of two sodalites and twenty five members of the nosean-haüyne solid solution series are given. It is evident from this study that potassium is a significant component substituting in the nosean-haüyne series, and that the cell edge shows a linear variation with the K2O content. The space groups of the minerals have been determined, and it is proposed that the space group be used as the criterion to distinguish nosean (space group P¯43m) from haüyne (space group P¯43n), owing to the lack of a suitable criterion in the composition, density, or refractive index of these minerals. Sharp compositional zoning in nosean and haüyne is reported. Data on the superstructure reflections of certain of the minerals are given and discussed. Finally means of identifying sodalite, nosean, and haüyne are suggested. 相似文献
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Chiaki Uyeda 《Physics and Chemistry of Minerals》1993,20(2):77-81
The diamagnetic anisotropy of oxide minerals is analyzed in terms of a new model, in which the anisotropy is assigned to the individual chemical bond in the [MO6] octahedral unit of the crystal. The diamagnetic principal axis of the individual M-O bond is assumed to be parallel to the direction of the bond. The calculated anisotropy based on this model shows a good correlation with the measured diamagnetic anisotropy, , for various minerals such as talc, sericite, kaolinite of the sheetsilicate group, forsterite of the orthosilicate group, and corundum of the hematite group. The values of many diamagnetic minerals are still unknown since the measurement is difficult to perform by means of conventional methods. The magnetic grain orientation recently observed in the mineral suspensions is effective for estimating the value, when the single crystal of the mineral cannot be obtained. The observation of fieldinduced crystal oscillation in the high magnetic fields can be applied for measuring the minerals with small values of less than 5 × 10–10 emu/cc. The chemical bond model on the diamagnetic anisotropy can be confirmed, when the compiling of data on various mineral is made by means of the above two methods. 相似文献