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1.
The paper presents critical analysis of literature data on the stability constants of aqueous species in the system Zn-O-H-S?II-Cl. In order to more accurately determine the composition and stability of chloride Zn complexes, additional experiments were carried out to determine the solubility of sphalerite ZnSc in chloride-sulfide solutions at 175°C and the saturated vapor pressure of the solution. Having processed the data, we obtained the thermodynamic properties at 25°C and parameters of the HKF (Helgeson-Kirkham-Flowers) equation of state (EoS) for hydroxide, chloride and hydrosulfide Zn complexes. The constants of sphalerite dissolution reactions with the formation of hydrosulfide and, particularly, chloride complexes increase with increasing temperature. The predominant Zn transport species in high-temperatures (>250°C) chloride-sulfide hydrothermal solutions are chloride complexes, first of all, ZnCl 4 2? . As the temperature decreases, the concentrations of complexes with smaller numbers of Cl? ligands increase. The region of weakly acidic to alkaline pH is dominated by hydrosulfide Zn complexes, but their concentrations in equilibrium with sphalerite are relatively low (a few ppm at 400°C and S concentrations <0.1 mol kg?1) and decreases with a temperature decrease. In the region dominated by chloride complexes, the concentration of dissolved Zn can amount to a few fractions of a percent at near-neutral pH, 400°C, and m(NaCl) = 1.0 and increases if the fluid becomes more acidic. An extremely important factor controlling the concentrations of dissolved Zn is temperature: cooling leads to the effective precipitation of sphalerite, particularly in the region dominated by chloride complexes. The thermodynamic properties of the solid phases and parameters of the HKF model for aqueous species in the system Zn-O-H-S-II-Cl are presented in the on-line version of the FreeGC database (http://www-b.ga.gov.au/minerals/research/methodology/geofluids/thermo/calculator/search.jsp), which enables calculating the Gibbs energy values of components of the system and reaction constants involving these components at PT parameters up to 600°C and 3 kbar.  相似文献   

2.
Peptides were released from organic matter fractions of three Italian soils (humin, humic and fulvic acids), when the samples were hydrolyzed in Ba(ON)2-saturated solution at 105°C for 2 hr. The peptides obtained were separated using electrophoresis and paper chromatography. The presence of polypeptides in the soil organic matter was indicated by: (1) their hydrolysis by pronase; (2) the amino acids released by 6 N HCl hydrolysis; (3) The comparison of i.r. spectra of humic fractions before and after hydrolysis with 6 N HCl.Attempts at isolating the native proteinaceous compounds using electrophoresis in polyacrylamide gel failed; additionally, our attempts to hydrolyze proteinaceous components enzymatically in unfractionated soil organic matter, as well as in its fractions, before and after methylation, with pepsin, papain and pronase, were unsuccessful. Pronase demonstrated a weak proteolytic activity only at very low substrate-enzyme ratios (20 : 1) in humic and fulvic fractions and in whole phyrophosphate extract. Deproteinated substrates treated with pronase also released free amino acids, suggesting autodigestion.In humin, humic and fulvic fractions we found a total amino acid content of 40–45%, 12–24% or 1–85, respectively. Amino acid recovery from single fractions was about 70–80% of the total content in the unfractionated soil.  相似文献   

3.
The solubility of chlorargyrite, AgClcr, was experimentally studied in NaCl solutions (0.1, 0.2, and 0.5 m) as a function of the concentration of boric acid (up to 5 m) at 70–300°C and saturated water vapor pressure. The experimental data indicated the existence of the chloroborate species B(OH)3Cl−. The published data on the thermodynamic properties of aqueous complexes in the B-Na-Cl-O-H system were analyzed. The obtained HKF parameters of aqueous species can be used to calculate equilibria in the system up to 350°C. Original Russian Text ? N.N. Akinfiev, M.V. Voronin, A.V. Zotov, V.Yu. Prokof’ev, 2006, published in Geokhimiya, 2006, No. 9, pp. 937–949.  相似文献   

4.
Organic matter from an arable soil derived from base rich parent material was extracted by alkali and fractionated on the basis of solubility in 0.1 N HCl, hot water and hot 6 N HCl and by selective adsorption on charcoal. The distribution of associated metals was determined and Cu had the largest proportion, 15%, associated with the organic matter. Moderate proportions of the total Al, Co, Ni, and V (3–8%) but only small amounts (?1%) of the Mn, Fe, Ti, Cr, Ba and Sr were extracted from the soil by alkali. The Fe and Ti were concentrated mainly in the humic fraction whereas Mn and V were both found largely in the fulvic acid.Electron paramagnetic resonance spectra of the various fractions were examined and attempts made to relate the spectra to the forms of some of the metals present. In the humic acid fraction Cu was present partly as a copper porphyrin-type complex but in the fulvic acid it was in some other complexed form. VO2+ occurred in complexed forms in the fulvic acid which were more covalent than VO2+ humic acid complexes, whereas the Mn2+ components of the humic and fulvic acids all had a high degree of ionicity.  相似文献   

5.
Humic acid adsorption onto the bacterial surface of Bacillus subtilis was measured with and without Cd, as a function of pH and humic–bacteria–Cd ratios. These experiments tested for the existence of ternary interactions in a bacteria–humic–metal system. We determine both the effects of humic acid on the bacterial adsorption of Cd, as well as the effects of the aqueous metal cation on the bacterial adsorption of humic acid. The presence of Cd does not affect the extent of humic acid adsorption onto the bacterial surface, indicating that there is no competition for sorption sites between humic acid and Cd under the experimental conditions, and that changes in the charging properties of the bacterial surface, as a result of the Cd adsorption, are not significant enough to affect humic acid adsorption.

The presence of humic acid does diminish Cd adsorption onto the bacterial surface, suggesting the presence of an aqueous Cd–humate complex under mid to high pH conditions. However, we also observe that the solubility of humic acid is unaffected by the presence of aqueous Cd. This apparently inconsistent behavior of an aqueous Cd–humate complex affecting Cd adsorption but not affecting humic acid solubility is not observed with simpler ionizable organic molecules. We propose that the solubility of humic acid is controlled by the solubility of a less soluble fraction of the acid. Cd forms an aqueous complex with the more soluble fraction of humic acid and there is no interdependence between the aqueous activities of the more and less soluble fractions. That is, the solubility of one humic acid fraction is unaffected by the presence of an aqueous Cd–humate complex involving another humic acid fraction. These experimental results constrain the relative importance of surface ternary and aqueous metal–humate complexes on the bacterial adsorption of both humic acid and metal cations.  相似文献   


6.
《Applied Geochemistry》1999,14(3):319-331
Despite the widespread occurrence of chlorophenols as groundwater contaminants, the aqueous solubilities of the chlorophenols are not well-characterized. In this study, the authors report the solubility of 2,4,6-trichlorophenol (2,4,6-TCP) and pentachlorophenol (PCP) based on experiments conducted as a function of pH, ionic strength and temperature, and a speciation-based model for estimating the solubilities of other chlorophenols is derived.Narrow constraints on the aqueous solubility of both chlorophenols were made possible by conducting experiments in pure water and in 0.1 NaCl at 25°C and 55°C, from both under- and over-saturation. The solubility of the chlorophenols is pH-independent under low pH conditions, but at higher pH values it increases with increasing pH. The concentration of the protonated chlorophenol species determines the low pH solubility and, at 25°C, the log molality of the protonated species of 2,4,6-TCP is −2.8±0.1, whereas for PCP the value is −5.1±0.3. Two other properties were used to model the solubility as a function of pH: the acidity constant (Ka) and the stability constant for a Na-chlorophenolate complex. The pKa and Na-chlorophenolate log stability constant values that best fit the solubility data for 2,4,6-TCP are 6.1±0.3 and 1.0±0.5, respectively; the values for PCP are 4.5±0.3 and 1.0±0.5, respectively. At 55°C, the log molality of protonated PCP increases to −4.7±0.2 and the pKa and log stability constant value are 4.1±0.3 and 0.9±0.5, respectively. The log stability constant for NaPCP° at 55°C is equal to 0.9±0.5.The experimental solubility measurements are used to construct a theoretical model which defines the solubility of a chlorophenol in terms of its acidity constant and its low pH minimum solubility. This approach enables estimations of the aqueous solubility of other chlorophenol molecules as a function of pH, ionic strength and temperature. In order to facilitate application of this model to other chlorophenol molecules, the authors compile and critically review the solubility data for 20 chlorophenols from the literature. The results of the experiments and review enable estimations of chlorophenol solubilities under a wide range of conditions of environmental interest.  相似文献   

7.
The aqueous silica species that form when quartz dissolves in water or saline solutions are hydrated. Therefore, the amount of quartz that will dissolve at a given temperature is influenced by the prevailing activity of water. Using a standard state in which there are 1,000 g of water (55.51 moles) per 1,000 cm3 of solution allows activity of water in a NaCl solution at high temperature to be closely approximated by the effective density of water, pe, in that solution, i.e. the product of the density of the NaCl solution times the weight fraction of water in the solution, corrected for the amount of water strongly bound to aqueous silica and Na+ as water of hydration. Generally, the hydration of water correction is negligible.The solubility of quartz in pure water is well known over a large temperature-pressure range. An empirical formula expresses that solubility in terms of temperature and density of water and thus takes care of activity coefficient and pressure-effect terms. Solubilities of quartz in NaCl solutions can be calculated by using that equation and substituting pe, for the density of pure water. Calculated and experimentally determined quartz solubilities in NaCl solutions show excellent agreement when the experiments were carried out in non-reactive platinum, gold, or gold plus titanium containers. Reactive metal containers generally yield dissolved silica concentrations higher than calculated, probably because of the formation of metal chlorides plus NaOH and H2. In the absence of NaOH there appears to be no detectable silica complexing in NaCl solutions, and the variation in quartz solubility with NaCl concentration at constant temperature can be accounted for entirely by variations in the activity of water.The average hydration number per molecule of dissolved SiO2 in liquid water and NaCl solutions decreases from about 2.4 at 200°C to about 2.1 at 350°C. This suggests that H4SiO4 may be the dominant aqueous silica species at 350°C, but other polymeric forms become important at lower temperatures.  相似文献   

8.
The Pb–Zn deposit at Jebel Ghozlane, in the Nappe zone (northern Tunisia), is hosted by Triassic dolostones and Eocene limestones and is located along faults and a thrust‐sheet boundary. The sulfide mineralization of the deposit consists mainly of galena and sphalerite and occurs as vein, stockwork, breccia, dissemination and replacement ores. Three hydrothermal stages are involved in the formation of the ores: stage I is dominated by celestite‐barite, hydrothermal dolomite DII, colloform sphalerite, and galena I; stage II consist of galena II; and stage III contains calcite. Galena in the deposit yielded average 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of 18.705, 15.667 and 38.734, respectively, suggesting a single upper crustal source reservoir for metals. Trace element data indicate the presence of Zn‐ and As‐free galena and As‐rich galena (with 0.2–0.5% As). Sphalerite contains 0.4% As, 0.7–0.9% Cd and 0.1–1.5% Fe. Microthermometric analysis of fluid inclusions in celestite shows that the deposit formed from fluids composed of heterogeneous mixtures of saline (19.5 ± 1 wt% NaCl eq.) aqueous solutions sourced from basinal brines, and gaseous CO2‐rich phases bearing low amounts of CH4, N2 and/or H2S, at temperatures of 172 ± 5°C.  相似文献   

9.
Data are presented in this study from laboratory model experiments describing the behaviour of Cu, Pb, Zn and Ni at a simulated sediment-water boundary. The interactions involved are sorption by kaolin and by bentonite, organic complexing in solution by fulvic acid and by humic acid, carbonate reactions, hydrolysis, and desorption of the cations from a clay-bound phase and from their metal hydroxides by the organic acids. The organic acids increase the solubility of Cu, Zn and Ni in the presence of clay. The Pb solubility is variable and can even decrease, particularly at acidic pH, with organic complexing likely due to colloidal coagulation. Both Zn and Ni are influenced by hydrolysis at basic pH. When carbonate was added to the metal-organic acid-clay mixtures, a further decrease in solubility was observed for Ni and, to a lesser extent, for Zn. The organic acids prove capable of remobilizing Cu, Pb, Zn and Ni from the solid phases examined. However, there is a general kinetic hindrance to the desorption particularly at basic pH. Copper desorption appears to be the most kinetically hindered. Conclusions pertinent to the geochemical dispersion of these metals are drawn.  相似文献   

10.
The aim of this work is to investigate the influence of pH and the metal:humic substances (HS) ratio on HS complexing capacity and the stability and solubility of metal–HS complexes in solution. We selected four HS with different physicochemical properties and studied their interaction with Cu(II), Zn(II) and Fe(II) at different pH and metal:HS ratios. The selected HS were a humic acid and a whole humic extract (containing the humic and fulvic acids) extracted from black peat, and a fulvic acid and a whole humic extract extracted from a compost of grape solid wastes.Our results showed that HS complexing capacity significantly varied as a function of pH, thus indicating the influence of both functional group ionisation and molecular conformation on this property. As was expected, total acidity affected the complexing capacity of the selected HS.The results related to stability and complexing capacity indicated the possible presence of two binding patterns, one at acid-neutral pH probably involving carboxylates, and another at alkaline pH probably involving carboxylates and phenolic groups. The relationship between these binding patterns and the strength of the binding process varied according to the complexed metal.Complex solubility was greatly affected by the ratio between the concentration of free ionised functional groups and the molecular weight in the HS studied.  相似文献   

11.
Insolubilized humic acid (IHA) was prepared in the laboratory by heating approach. Through the comparison between the endothermic peaks, optimal heating temperature was determined to be 330°C. The modified IHA then was characterized by TG-DTA, SEM, FTIR, element analysis, and nitrogen adsorption–desorption isotherms. The removal efficiency of p-nitrophenol from the aqueous solution by adsorption onto solid IHA surfaces was shown to be a function of pH, reaction temperature, and p-nitrophenol concentration. Adsorption equilibrium data satisfactorily fitted the Langmuir adsorption isotherm. Under a certain concentration range, the removal rate of p-nitrophenol at pH 3.5 could reach 24, 29, and 35 mg/g at a temperature of 25, 35, and 45±0.1°C. The results suggest that IHA could play a role as a potential efficient absorbent to remove organic contaminants, e.g., utilized to purify water contaminated by organic compounds.  相似文献   

12.
The solubility of fluorite in NaCl solutions increases with increasing temperature at all ionic strengths up to about 100°C. Above this temperature, the solubility passes through a maximum and possibly a minimum with increasing temperature at NaCl concentrations of 1.0M or less, and increases continuously with increasing temperature at NaCl concentrations above 1.0M. At any given temperature, the solubility of fluorite increases with increasing salt concentration in NaCl, KCl and CaCl2 solutions. The solubility follows Debye-Hückel theory for KCl solutions. In NaCl and CaCl2 solutions, the solubility of fluorite increases more rapidly than predicted by Debye-Hückel theory: the excess solubility is due to the presence of NaFc, CaF+, and possibly of Na2F+. The solubility of fluorite in NaCl-CaCl2 and in NaCl-CaCl2-MgCl2 solutions is controlled by the common ion effect and by the presence of NaFc, CaF+, and MgF+. The solubility of fluorite in NaCl-HCl solutions increases rapidly with increasing initial HCl concentration; the large solubility increase is due to the presence of HFc. It seems likely that complexes other than those identified in this study rarely play a major role in fluoride transport and fluorite deposition at temperatures below 300°C.  相似文献   

13.
The Mount Black Pb‐Zn deposit is a quartz‐galena‐sphalerite replacement body in the Silurian Cooleman Limestone. Fluid inclusion homogenisation temperatures range from 120° to 170°C for paragenetically early sphalerite, to 210° to 315°C for late quartz, and 245° to 320°C for calcite from contiguous recrystallised limestone. Fluid salinities increased with rising temperature, during deposition of the minerals, and the fluid composition changed from NaCl‐rich to possibly CaCl2‐NaCl (‐?MgCl2)‐rich brines.

δ34S values of sphalerite and galena range from —8.1 to —2.7 per mil, and —13,5 to —4.4 per mil respectively. Although a magmatic source for sulphur is not excluded, it is suggested that most probably the sulphur was derived by biogenic reduction of sea‐water sulphate during diagenesis. Carbon and oxygen isotope data for the Cooleman Limestone range from compositions typical of Silurian marine carbonate in samples distant from the deposit, to fluctuating, but 12C‐ and 16O‐enriched in recrystallised material adjacent to the quartz‐sulphide rocks. 12C‐enrichment probably reflects organic carbon oxidation during karst formation, continuing later during limestone recrystallisation and accompanied by 16O‐enrichment during the action of saline formation waters.

The process of formation of the Mount Black deposit may have been analogous to that of Mississippi Valley‐type deposits, but modified by and/or resulting from, an increasing geothermal gradient caused by nearby synchronous intrusions.  相似文献   

14.
The Chehugou Mo–Cu deposit, located 56 km west of Chifeng, NE China, is hosted by Triassic granite porphyry. Molybdenite–chalcopyrite mineralization of the deposit mainly occurs as veinlets in stockwork ore and dissemination in breccia ore, and two ore‐bearing quartz veins crop out to the south of the granite porphyry stock. Based on crosscutting relationships and mineral paragenesis, three hydrothermal stages are identified: (i) quartz–pyrite–molybdenite ± chalcopyrite stage; (ii) pyrite–quartz ± sphalerite stage; and (iii) quartz–calcite ± pyrite ± fluorite stage. Three types of fluid inclusions in the stockwork and breccia ore are recognized: LV, two‐phase aqueous inclusions (liquid‐rich); LVS, three‐phase liquid, vapor, and salt daughter crystal inclusions; and VL, two‐phase aqueous inclusions (gas‐rich). LV and LVS fluid inclusions are recognized in vein ore. Microthermometric investigation of the three types of fluid inclusions in hydrothermal quartz from the stockwork, breccia, and vein ores shows salinities from 1.57 to 66.75 wt% NaCl equivalents, with homogenization temperatures varying from 114°C to 550°C. The temperature changed from 282–550°C, 220–318°C to 114–243°C from the first stage to the third stage. The homogenization temperatures and salinity of the LV, LVS and VL inclusions are 114–442°C and 1.57–14.25 wt% NaCl equivalent, 301–550°C and 31.01–66.75 wt% NaCl equivalent, 286–420°C and 4.65–11.1 wt% NaCl equivalent, respectively. The VL inclusions coexist with the LV and LVS, which homogenize at the similar temperature. The above evidence shows that fluid‐boiling occurred in the ore‐forming stage. δ34S values of sulfide from three type ores change from ?0.61‰ to 0.86‰. These δ34S values of sulfide are similar to δ34S values of typical magmatic sulfide sulfur (c. 0‰), suggesting that ore‐forming materials are magmatic in origin.  相似文献   

15.
The solubility of synthetic ZnS(cr) was measured at 25–250 °C and P = 150 bars as a function of pH in aqueous sulfide solutions (~ 0.015–0.15 m of total reduced sulfur). The solubility determinations were performed using a Ti flow-through hydrothermal reactor. The solubility of ZnS(cr) was found to increase slowly with temperature over the whole pH range from 2 to ~ 10. The values of the Zn–S–HS complex stability constant, β, were determined for Zn(HS)20(aq), Zn(HS)3?, Zn(HS)42?, and ZnS(HS)?. Based on the experimental values the Ryzhenko–Bryzgalin electrostatic model parameters for these stability constants were calculated, and the ZnS(cr) solubility and the speciation of Zn in sulfide-containing hydrothermal solutions were evaluated. The most pronounced solubility increase, about 3 log units at m(Stotal) = 0.1 for the temperatures from 25 to 250 °C, was found in acidic solutions (pH ~ 3 to 4) in the Zn(HS)20(aq) predominance field. In weakly alkaline solutions, where Zn(HS)3? and Zn(HS)42? are the dominant Zn–S–HS complexes, the ZnS(cr) solubility increases by 1 log unit at the same conditions. It was found that ZnS(HS)? and especially Zn(HS)42? become less important in high temperature solutions. At 25 °C and m(Stotal) = 0.1, these species dominate Zn speciation at pH > 7. At 100 °C and m(Stotal) = 0.1, the maximum fraction of Zn(HS)42? is only 20% of the total Zn concentration (i.e. at pHt ~ 7.5), whereas at 350 °C and 3 <pHt <10, the fraction of Zn(HS)42? and ZnS(HS)? is less than 0.05% and 2.5% respectively, of the total Zn concentration and Zn(HS)20 and Zn(HS)3? predominate. The measured equilibrium formation constants were combined with the literature data on the stability of Zn–Cl complexes in order to evaluate the concentration and speciation of Zn in chloride solutions. It was found that at acidic pH, and in more saline fluids having total chloride > 0.05 m, Zn–Cl complexes are responsible for hydrothermal Zn transport with no significant contribution of Zn–S–HS complexes. The hydrosulfide/sulfide complexes will play a more important role in lower salinity (< 0.05 m chloride) hydrothermal solutions which are characteristic of many epithermal ore depositing environments. The value of ΔfG° (β-ZnS(cr)) = ? 198.6 ± 0.2 kJ/mol at 25 °C was determined via solubility measurements of natural low-iron Santander (Spain) sphalerite.  相似文献   

16.
Dissolved aromatic compounds in Hungarian thermal waters were first reported more than 10 years ago. Among the identified compounds were alkylbenzene, polyaromatic hydrocarbon and heteroaromatic homologue series. The appearance of dissolved organic compounds has been bound to a threshold temperature of ∼80 °C, and their distribution is controlled by the water temperature. Relative demethylation and aromatisation were observed with increasing temperature. The origin of these compounds is not proved. Among precursor candidates are humic substances.Simulation experiments were carried out on humic and fulvic acid and on their mixture to gain information on aromatic compounds formed. The samples were heated and products were measured with GC-MS.In the presence of oxygen, increasing concentration of benzene can be observed as a function of temperature. Toluene and thiophene can be identified, other alkylbenzenes are missing. Under reductive conditions the concentration of benzene, toluene and the ratio of short to long chained aromatics generally increases in every sample as a function of temperature. Main compounds are toluene and benzene. The amount of heteroaromatic compounds increases with temperature, but their relative concentration compared to aromatic hydrocarbons decreases. At higher temperatures the proportion of pyrroles drops and S and O containing ones become dominant.The different processes (formation, aromatisation, polycondensation, relative demethylation, decomposition) occur in parallel but their relative intensities vary as a function of temperature. The effects of duration and increasing temperature are similar but not equal: both demethylation and aromatisation can be observed.  相似文献   

17.
Mineralogical, geochemical and fluid inclusion studies reveal two favorable environments for the localisation of beryl mineralisations in the Precambrian rocks of Egypt: (1) emerald-schist; and (2) beryl-specialised granitoid associations. Emerald occurs within the mica schists and is typically confined to the Nugrus major shear zone. However, beryl associated with granitoids occurs in pegmatite veins, greisen bodies, and cassiterite quartz veins cutting the granites and the exocontacts of the volcanosedimentary country rocks.Compositionally, emerald is of octahedral type and its cell edge is lengthened along the a-axis, while beryl associated with granitoids is normal in composition and structural constants. Emerald is thought to be formed as the result of epitactic nucleation of Be, Al and alkali-rich solutions on the mica of the schist country rocks. Fluid inclusion studies show that the solutions are saline (8–22 wt% NaCl equiv.) and the reactions proceeded in the temperature range 260–382°C. On the other hand, aqueous inclusions in beryl associated with granitoids show the following sequence of formation with decreasing temperatures and salinities: beryl pegmatite (320–480°C and 7–16 wt% NaCl equiv.)→greisen bodies (190–400°C and 4–7 wt% NaCl equiv.)→cassiterite-quartz veins (190–380°C and 2–4 wt% NaCk equiv.).This study suggests that factors such as the chemistry of the Be-bearing fluids (rather than that of the bulk host schists) and syn-tectonic intrusions of leucogranites and pegmatites (Bederiving sources) along major ductile shear zones are the important factors controlling emerald formation. However, the endogreisens and exogreisens are the most important targets characterising the metasomatically- and magmatically-specialised, Be-granitoids, respectively. The aqueous inclusions examined in greisen beryls of metasomatised granites show a shorter range of homogenisation temperatures (260–390°C) and salinities(4.8-7 wt% NaCl equiv.) as compared to those of magmatically-specialised granitoids (190–400°C and 4–7 wt% NaCl equiv.). This phenomenon can be partly attributed to the late development of the fracture system during the crystallisation history of the metasomatised granites, where little or no contribution from meteoric waters occurred.  相似文献   

18.
有机—铜配合物热稳定性及热分解产物的实验研究   总被引：2，自引：0，他引：2  
庄汉平  冉崇英 《现代地质》1996,10(3):408-413
通过实验研究了富里酸、氨基丙酸和半胱氨酸３种有机质与铜的配合物的热稳定性及热分解产物特征。结果表明：富里酸—铜配合物在１９０～２００℃时缩合成类干酪根物质，被富里酸配合的铜一同进入到该物质中去；氨基丙酸—铜配合物在１４０～１５０℃分解，形成π键配合物“二（三）氯·（乙炔）合铜（Ⅰ）”；半胱氨酸—铜配合物很不稳定，８０℃便开始分解，生成黑色沉淀物“二水合四氯合铜酸铵”，而没有生成铜的金属硫化物  相似文献   

19.
Water samples from Narragansett Bay and the Providence River, and fulvic acid/ saline water solutions were examined for their ability to solubilize n-alkane (n-C16 and n-C20), isoprenoid (pristane) and aromatic (phenanthrene and anthracene) hydrocarbons and dibutyl phthalate. Removal of the dissolved organic matter (D.O.M.) from the natural samples by activated charcoal and by ultra-violet oxidation resulted in a 50–99 per cent decrease in the amounts of n-alkanes and isoprenoid hydrocarbons solubilized. This decrease was directly related to the amount of D.O.M. removed. The solubilities of the aromatic hydrocarbons were unaffected by the D.O.M. Fulvic acid from a marine sediment, surface active organic material isolated at a chloroform/sea water interface, organic material extracted from a marine sediment by sea water, and organic matter contributed by a municipal sewage effluent, promote n-alkane solubility when added to NaCl solutions and re-enhance solubility when added to organic depleted sea water. The solubility of No. 2 fuel oil increased 2.5 times in the presence of fulvic acid (3.7 mg C/l.) with most of the increase seen in the alkane and isoprenoid components.N-Alkane solubility increases in fulvic acid/saline water solutions with increasing pH and reaches a maximum with respect to ionic strength at I = 0.3. There is evidence to suggest that the mode of solubilization of the hydrocarbons is by incorporation into micelles formed by intermolecular association of the surface active humic-type monomers. The presence of ionic species is a prerequisite for micelle formation.  相似文献   

20.
Information from a database, which was compiled and continuously updated by the authors of this paper and now includes information from 19500 publication on fluid and melt inclusions in minerals, is used to summarize results on the physicochemical formation parameters of hydrothermal Au, Ag, Pb, and Zn deposits. The database provides information on fluid inclusions in minerals from 970 Pb-Zn, 220 Au-Ag-Pb-Zn, and 825 Au-Ag deposits in various settings worldwide. Histograms for the homogenization temperatures of fluid inclusion are presented for the most typical minerals of the deposits. In sphalerite, most homogenization temperatures (1327 measurements) of fluid inclusions lie within the range of 50–200°C with a maximum at 100–200°C for this mineral from Pb-Zn deposits and within the range of 100–350°C (802 measurements) with a maximum at 200–300°C for this mineral from Au deposits. Data are presented on fluid pressures at Au (1495 measurements) and Pb-Zn (180 measurements) deposits. The pressure during the preore, ore-forming, and postore stages at these deposits ranged from 4–10 to 6000 bar. The reason for the high pressures during preore stages at the deposits is the relations of the fluids to acid magmatic and metamorphic processes. More than 70% of the fluid pressures values measured at Pb-Zn deposits lie within the range of 1–1500 bar. Au-Ag deposits are characterized by higher fluid pressures of 500–2000 bar (61% of the measurements). The overall ranges of the salinity and temperature of the mineral-forming fluid at Au-Ag (6778 measurements) and Pb-Zn (3395 measurements) deposits are 0.1–80 wt % equiv. NaCl and 20–800°C. Most measurements (～64%) for Au-Ag deposits yield fluid salinity <10 wt % equiv. NaCl and temperatures of 200–400°C (63%). Fluids at Pb-Zn deposits are typically more saline (10–25 wt % equiv. NaCl, 51% measurements) and lower temperature (100–300°C, 74% measurements). Several measurements of the fluid density fall within the range of 0.8–1.2 g/cm3. The average composition of volatile components of the fluids was evaluated by various techniques. The average composition of volatile components of fluid inclusions in minerals is calculated for hydrothermal W, Au, Ag, Sn, and Pb-Zn deposits, metamorphic rocks, and all geological objects. The Au, Ag, Pb, and Zn concentrations in magmatic melts and mineral-forming fluids is evaluated based on analyses of individual inclusions.  相似文献   

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