Solubility and migration ability of rhodium in natural conditions: model experimental data     

I. Ya. Koshcheeva  I. V. Kubrakova  N. V. Korsakova  O. A. Tyutyunnik 《Geochemistry International》2016,54(7):624-632

The contents of dissolved rhodium species in the near-neutral environments have been studied for the first time and data on the interaction of Rh with organic matters of natural waters and its sorption behavior during contact with the components of geochemical barriers were obtained. The solubility method was used to analyze the behavior of rhodium hydroxide in the Rh(OH)_x–H₂O and Rh(OH)_x–H₂O–FA (fulvic acids) systems. The possible contents of inorganic species of rhodium and its compounds with humic organic ligands were determined within the pH range typical of surface waters. The solubility of rhodium shows a twoorder- of magnitude increase in the presence of humic matters (FA). The sorption interaction of the soluble rhodium species with the main components of geochemical barriers such as iron oxyhydroxides (III), (including fulvic-acid modified ones), alumosilicates, and precipitates of humic acids in contact with natural waters was studied. It was revealed that rhodium has the high affinity to all studied materials; its species are sorbed by ferrihydrite within several hours. It is suggested that rhodium is mainly transferred as colloid with suspended particulate matters of waters and then is accumulated in bottom sediments. The differences revealed in the sorption behavior of Pt(IV), Pd(II) and Rh(III) may be used to predict the distribution of the considered platinum group elements between the components of ecosystems.  相似文献   

Role of organic matter in the accumulation of platinum in oceanic ferromanganese deposits     

I. V. Kubrakova  I. Ya. Koshcheeva  O. A. Tyutyunnik  A. M. Asavin 《Geochemistry International》2010,48(7):655-663

In order to elucidate possible processes leading to platinum accumulation in ferromanganese deposits, we analyzed published data on the interaction of dissolved platinum species in different valence states with iron and manganese oxyhydroxides under oceanic conditions and experimentally studied the kinetics of sorption of inorganic and organic complexes of platinum (II) and platinum (IV) on synthetic iron and manganese oxyhydroxides and natural materials (marine colloids, and ferromanganese crust samples). The role of dissolved and suspended particulate aquatic organic matter in the sorption accumulation of platinum was evaluated. Possible reasons for the preferential (compared with other noble metals) accumulation of platinum in oceanic ferromanganese deposits were discussed.  相似文献   

Migration behavior of platinum group elements in natural and technogeneous systems     

I. V. Kubrakova  O. A. Tyutyunnik  I. Ya. Koshcheeva  A. Yu. Sadagov  S. N. Nabiullina 《Geochemistry International》2017,55(1):108-124

Data were summarized on the speciation of the main platinum group elements (PGE) platinum, palladium, and rhodium in aqueous media, forms of their input into the environment, and mechanisms of accumulation by natural sorptive phases. In some cases, the results obtained for PGE were compared with those for gold. Data on PGE speciation in a number of natural environments were analyzed. It was found that the main factor controlling the migration ability of PGE (Pd > Pt»Rh) is the formation of stable compounds with dissolved organic matter, hydroxyl, and thiosulfate ions and nanometer-sized particles. The transport of dissolved PGE species by marine, riverine, and technogeneous suspended materials was evaluated as an alternative way of an increase in PGE mobility. Significant differences were revealed in the migration behavior of platinum, palladium, and rhodium indicating the dominance of palladium dissipation in a dissolved state. The possibility of the prediction of PGE accumulation and dissipation in technogeneous systems was demonstrated.  相似文献   

Interaction of Rh(III) with Humic Acids and Components of Natural Adsorption Phases     

I. Ya. Koshcheeva  N. V. Korsakova  O. A. Tyutyunnik  I. V. Kurbakova 《Geochemistry International》2018,56(7):711-718

To study the migration and accumulation of Rh(III) in natural systems, we have synthesized complexes of Rh(III) and fulvic acids (FA), which are dominant organic compounds of natural waters. The composition of rhodium hydroxofulvate complexes is determined at pH 7.0, and the stability constant of these complexes is calculated. Data are obtained on interaction of FA and Rh(III) hydroxofulvate complexes with components of naturally occurring reactive barriers (ferrihydrite, quartzite, clay shale, and natural aluminosilicate suspensions) at pH 4.0–8.0. The adsorption behavior of FA and rhodium fulvate complexes at the sorbents was determined to be analogous.  相似文献   

Sorption on Humic Acids as a Basis for the Mechanism of Primary Accumulation of Gold and Platinum Group Elements in Black Shales     

Varshal  G. M.  Velyukhanova  T. K.  Chkhetiya  D. N.  Kholin  Yu. V.  Shumskaya  T. V.  Tyutyunnik  O. A.  Koshcheeva  I. Ya.  Korochantsev  A. V. 《Lithology and Mineral Resources》2000,35(6):538-545

In order to asses the contribution of sorption by complexation to the concentration of noble metals at early stages of the formation of their deposits in black shales, the sorption of Au(III), Pt(IV), Rd(II), Rh(III), Ru(IV), and Os(IV) ions was studied on ash-free preparations of humic acids (HA) separated from peat of the Tver region and marine sediment samples taken on the Peruvian shelf. Data on the nature and protolytic characteristics of oxygen-containing HA functional groups were obtained. It has been shown that carboxyl groups and phenol oxygroups, which ensure the HA complexation with ions of noble metals, are present in the HA structure. The dissociation constant values for HA carboxyl groups (pK_a) and the distribution function of these groups in their pK_a values have been established. It has been revealed that the pK_a value for both of the HA groups varies within two orders of magnitude: the average value is equal to 6.1 for HA from peat and 7.0 for HA from marine sediments. A fairly high and similar for both of the HA groups sorption capacity with respect to Au(III), Rd(II), Rh(III), Ru(IV), and Os(IV) ions was established in model experiments. It is equal to 320–350 mg g^–1 for Au, 100–110 mg g^–1 for Pd, 11–12 mg g^–1 for Rh, 16–19 mg g^–1 for Ru, and 23 mg g^–1 for Os. The study of platinum(IV) sorption revealed that humic acids from peat and marine sediments do not virtually sorb Pt(IV), and this observation is important for understanding genetic features of the formation of noble metal deposits in black shales. Based on sorption isotherms for Au(III), Pd(II), Rh(III), and Ru(IV), the conditional affinity constant values for HA sorption centers with respect to ions of these metals were calculated by the method of quantitative physicochemical analysis. These values prove that complex compounds forming at the HA surface possess a high strength: the log values for the Au(III)–HA, Pd(II)–HA, Rh(III)–HA, and Ru(IV)–HA compounds are equal to 6.0, 5.0, 3.2, and 3.5, respectively.  相似文献   

Migration of platinum,palladium, and gold in the water systems of platinum deposits     

I. V. Kubrakova  A. V. Fortygin  S. G. Lobov  I. Ya. Koshcheeva  O. A. Tyutyunnik  M. V. Mironenko 《Geochemistry International》2011,49(11):1072-1084

In order to explore the behavior of platinum group elements in the ecosystems of mineral deposits, the migration characteristics of platinum and palladium were determined in the pH range typical of surface waters. Model sorption experiments on the precipitation of platinum and palladium on iron oxyhydroxide in the presence of major natural inorganic and organic ligands showed that platinum interacts most actively with an iron oxyhydroxide (ferrihydrite) precipitate within the whole pH range, both in the absence and presence of natural organic substances, whereas palladium is preferentially bound to dissolved, suspended, and sedimentary humic substances. The thermodynamic calculation of coexisting platinum and palladium species is qualitatively consistent with experimental data on the character of accumulation and migration of these elements. The obtained data suggest that the migration of platinum and palladium into highly colored waters in the zones of platinum group element deposits results in their extensive deposition on natural geochemical barriers.  相似文献   

Interaction of Cr(III) with the humus acids of soil,water, and bottom sediments     

I. Ya. Koshcheeva  S. D. Khushvakhtova  V. V. Levinskii  V. N. Danilova  Yu. V. Kholin 《Geochemistry International》2007,45(2):178-184

The interaction of Cr(III) with humus acids [fulvic (FA) and humic (HA) acids] was studied in the systems Cr(III)-FA, Cr(III)-HA, and Cr(III)-FA-HA. Chromium(III) reacts with FA extracted from the headwaters of the Moscow River and from the Krapivenka River (a tributary of Lake Seliger) to form a highly soluble high-molecular-weight Cr(III)-hydroxofulvate complexes with \(\bar \beta _{11} \) = 1.93 × 10⁶ and 5.70 × 10⁶, respectively. Humic acids extracted from peat in the Tver area and the sapropel of Lake Seliger behave as complexing sorbents with conditional affinity constants logβ = 3.78 and 3.23 for Cr(III) sorption at HA sites in the peat and sapropel, respectively. In the three-component system Cr(III)-FA-HA, the Cr(III) distribution coefficient between solution and precipitate is controlled by the pH value and FA content in the solution and decreases by 1–1.5 orders of magnitude with increasing fulvic acid content.  相似文献