Journal articles on the topic 'Chromium complex dyes'
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1
Yildiz, E., and N. Bozok. "Synthesis of Compounds Containing Fluorine, Vinylsulfone Groups and Transition Metal Complexes and their Applications to Textiles." E-Journal of Chemistry 5, s1 (2008): S997—S1007. http://dx.doi.org/10.1155/2008/348037.
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A ligand which has reactive dye character and its transition metal complexes such as Cu(II), Co(II), Cr(III), Ni(II) containing vinylsulfone and fluorine groups were synthesized. The diazotation reaction has been studied at 0-5°C carefully. Completion of the reaction was monitored by the TLC method. FT-IR, UV,1H-NMR, TGA and microanalysis methods were used for determination of the synthesized compounds. We assumed that copper complex indicated dimeric structure based on magnetic susceptibility result. All the synthesized compounds which have dye character were applied on cotton, polyamide and nylon fibers. Their dyeing and fastness properties were investigated according to international standards. These properties gave good results for all synthesized dyes except light fastnesses of chromium and nickel complex dyes.
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Wang, Ing Jing, Yu Jen Hsu, and Jyn Hen Tian. "Synthesis and properties of some pyridone chromium complex azo dyes." Dyes and Pigments 16, no. 2 (January 1991): 83–91. http://dx.doi.org/10.1016/0143-7208(91)85001-o.
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Copaciu, Florina-Maria, Dorina Simedru, and Maria-Virginia Coman. "Determination of Three Chromium Textile Azo Dyes in Wastewater by SPE-LC-ESI(–)-MS/MS." Journal of AOAC INTERNATIONAL 101, no. 5 (September 1, 2018): 1422–28. http://dx.doi.org/10.5740/jaoacint.18-0059.
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Abstract In the present work, a procedure to determine three textile azo dyes, chromium-complexes [Nylosan Dark Brown (NDB), Lanasyn Dark Brown (LDB), and Lanasyn Red (LR)], from wastewater using solid-phase extraction (SPE) followed by LC-electrospray ionization negative mode tandem mass spectrometry (LC-ESI(–)-MS/MS) has been developed. The extraction/concentration and recovery degree of these dyes from liquid matrices were done on Strata WAX/NH2 cartridges. The chromatographic separation was performed using a Luna C18 (2) 100Å column by isocratic elution with a methanol–acetonitrile–water (0.2% formic acid and 2 mM ammonium formate) mixture. The linearity, the LOD, and the LOQ were determined for each textile dye. The accuracy, the precision (intra- and inter-day), and the matrix effect were also performed for the validation of the developed procedure. These chromium-complex azo dyes often used in the dyeing process by a textile factory in Romania were monitored in the influent and effluent wastewater from a treatment plant situated in its area. Applying the developed SPE-LC-ESI(–)-MS/MS procedure, the following textile dyes were detected (ng/L) in the collected wastewater samples during a 24-h period: NDB 150.1, LDB 200.6, and LR 89.0–244.0 in influents and NDB 22.8, LDB 78.6, and LR 74.0 in effluents.
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RACE, E., F. M. BOWE, and J. B. SPEAKMAN. "The Nature of the Dye-Chromium-Fibre Complex in the Case of Wool Dyed with Certain Chrome Mordant Dyes." Journal of the Society of Dyers and Colourists 62, no. 12 (October 22, 2008): 372–83. http://dx.doi.org/10.1111/j.1478-4408.1946.tb02390.x.
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Arslan-Alaton, I., I. Kabdaşlı, and S. Teksoy. "Effect of Fenton's treatment on the biodegradability of chromium-complex azo dyes." Water Science and Technology 55, no. 12 (June 1, 2007): 107–12. http://dx.doi.org/10.2166/wst.2007.388.
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Pretreatment of an acid dyebath effluent bearing a new generation chromium complex azo dyestuff (Co=350 mg/L) with Fenton's reagent was investigated. Preliminary optimisation (baseline) experiments were conducted to determine the Fe2 + , H2O2 concentrations and pH required to the highest possible COD and colour removals. Kinetic studies were carried out at varying temperatures (20 °C < T<70 °C) to establish a relationship between COD abatement and H2O2 consumption. The activation energy found for catalytic H2O2 decomposition (Ea=9.8 kJ/mol) appeared to be significantly less than that of fermentative (Ea=23 kJ/mol) and of thermal (Ea=76 kJ/mol) H2O2 decomposition, implying that H2O2 decomposition during the Fenton's reaction occurs more spontaneously. The experimental studies indicated that approximately 30% COD and complete colour removal could be achieved under optimised Fenton pretreatment conditions (Fe2 + =2 mM; H2O2=30 mM; pH = 3; at T = 60 °C). Long-term activated sludge experiments revealed that although the raw and pretreated acid dyebath effluent contained practically the same amount of “readily biodegradable” COD (inert COD fraction ≤10%), biodegradation of the chemically pretreated acid dye effluent proceeded appreciably faster than that of the untreated acid dyebath effluent.
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Ghosh, Arpita, Manisha Ghosh Dastidar, and T. R. Sreekrishnan. "Response surface modeling of bioremediation of acid black 52 dye using Aspergillus flavus." Water Science and Technology 75, no. 12 (March 21, 2017): 2864–74. http://dx.doi.org/10.2166/wst.2017.167.
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Bioremediation is an efficient process to remove metals and dyes from solutions using different micro-organisms. In the present study, the efficiency of growing Aspergillus flavus (isolated from the effluent of an electroplating industry) to treat a synthetic solution of acid black 52 dye (a trivalent chromium complex dye) was investigated. Maximum removal of dye and chromium was observed to be 390 and 17.22 mg/L, respectively, at an initial dye concentration of 750 mg/L and at pH 4.5 in 50 hours in a batch bioreactor. The biomass concentration was reduced from 4.1 to 0.4 g/L with increasing dye concentration from 100 to 2,000 mg/L. The response surface modeling for color removal was performed using the range of initial dye concentration 200–400 mg/L, pH 4–6 and time 35–50 hours. The optimum conditions for maximum color removal (76.52%) were observed at initial dye concentration: 200 mg/L, pH: 4.75 and time: 50 hours. The deviation (−0.02%) showed a close agreement between the experimental and predicted values of color removal. The scanning electron microscopic and energy dispersive X-ray analyses indicated bioremediation of the dye.
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Ghosh, Arpita, Manisha Ghosh Dastidar, and T. R. Sreekrishnan. "Bioremediation of chromium complex dyes and treatment of sludge generated during the process." International Biodeterioration & Biodegradation 119 (April 2017): 448–60. http://dx.doi.org/10.1016/j.ibiod.2016.08.013.
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Vostrikova, N. L., M. Yu Minaev, and K. G. Chikovani. "Determining the authenticity of turmeric." Food systems 4, no. 1 (April 28, 2021): 62–70. http://dx.doi.org/10.21323/2618-9771-2021-4-1-62-70.
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The paper examines the problem of the composition instability in the ready ground spice, turmeric. Analysis of the prevalent methods for turmeric adulteration and substances used for these purposes is given. The visual assessment of color tints of the turmeric root, spices containing it and chemical dyes based on chromium salts is presented. The studies on determination of the lead and chromium content were carried out to study the content of these metals and test the hypothesis of using lead chromate as a dye in adulteration of turmeric. Using the method of electrothermal atomic absorption spectroscopy, it was found that the lead content in the analyzed turmeric samples varied from 1.72 ± 0.58 to 5.03 ± 1.80 mg/kg, while the chromium content was in a range of 5.56 ± 0.85 to 16.15 ± 2.32 mg/kg. As a result of species specific PCR, wheat DNA was revealed in all purchased samples of ground turmeric. The levels of the main raw material replacement were established, which were 0.14% to 14.95% with the correlation coefficient close to 100%; efficiency of the reaction was 1.95, which was 97.5% when expressed as percentage. These levels of an undeclared allergen in the product composition can cause a serious allergic reaction. The authors tested the hypothesis of introduction of sodium and potassium salts for correction of the color spectrum in the ready spice and its correspondence to the natural color within the color spectrum of turmeric. As a result of the complex study of the spice composition, quite high values of chromium were found, presumably not only from the lead chromate compound but also from chromic acid salts, as the high level of potassium that significantly exceeded the native content of this element was found.
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Choe, Eun Kyung, Young-Zu Kim, Young Dal Cho, and Seung Hwan Son. "Study on analytical scheme for human ecological quality control of chromium-complex acid dyes." Textile Research Journal 86, no. 17 (July 22, 2016): 1847–58. http://dx.doi.org/10.1177/0040517515617421.
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Wołowicz, Anna, Monika Wawrzkiewicz, and Zbigniew Hubicki. "Toxic Heavy Metal Ions and Metal-Complex Dyes Removal from Aqueous Solutions Using an Ion Exchanger and Titanium Dioxide." Fibres and Textiles in Eastern Europe 26, no. 2(128) (April 30, 2018): 108–14. http://dx.doi.org/10.5604/01.3001.0011.5748.
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The aim of the study was to compare the removal efficiency of toxic heavy metal ions: chromium(VI), nickel(II) and copper(II) as well as metal-complex dyes from aqueous solution using Lewatite VPOC 1065 and AdsorbsiaTM As500. The point of zero charge (pHPZC) of both sorbents and the influence of the initial concentration on the sorption process of Ni(II), Cu(II), Cr(VI), C.I. Acid Red 183 (AR183), C.I. Reactive Blue 21 (RB21) and nickel(II) phthalocyanine-tetrasulfonic acid tetrasodium salt (NiPc-TSATSS) were studied to determine the maximum sorption capacity. Kinetic studies were also carried out for the most effective sorbent-sorbate systems. The concentration effect of both hydrochloric acid and auxiliaries on the removal yield was also taken into account. As was found, Lewatit VPOC 1065 can be successfully applied for the treatment of textile wastewaters containing metal complex dyes and heavy metal ions. The highest sorption capacity, qe = 816.1 mg/g, was found for C.I. Acid Red 183.
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Szewczyńska, Małgorzata, and Małgorzata Pośniak. "Chromium(VI) compounds – inhalable fraction. Determining in workplace air with ionic chromatography." Podstawy i Metody Oceny Środowiska Pracy 35, no. 3(97) (September 30, 2018): 17–34. http://dx.doi.org/10.5604/01.3001.0012.4755.
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The metallurgical, mining and tanning industries are, among others, very important sources of chromium compounds emission to the environment. Moreover, chromium is widely used in the production of dyes, pigments, paints and wood preservatives. Welding processes are one of the sources of exposure to chromium compounds under occupational conditions. Long-term occupational exposure to Cr(VI) chromium compounds increases the risk of developing lung or nasal cancer. The aim of the study was to develop a method for selective determination of Cr(VI) compounds in the workplace air with a combination of ion chromatography technique and post-column derivatisation. The method is based on separating the inhalable fraction of chromium(VI) compounds on a filter using an I.O.M. type probe, extraction with 10 mL of 2% sodium hydroxide/3% sodium carbonate solution and further analysis with ionic chromatography with a post-column reaction of Cr(VI) with 1.5-diphenyl carbazide (DPC) and spectrophotometric determination of the formed Cr(VI)-DPC complex. The measuring range for chromium (VI) compounds is 0.072–1.44 µg/mL. Precision, chromium recovery from filters, limit of detection and quantification were calculated. The overall uncertainty was 12.2 %. The expanded uncertainty for Cr(VI) was 24.3%. The developed method enables the separation and quantification of Cr(VI) compounds in the presence of Cr(III) compounds in air samples (avoiding adverse reactions of one form of chromium to another) at a level of 0.0009 mg/m3 for Cr(VI) compounds converted into Cr at 720-L intake of air. The procedure for determining chromium(VI) compounds is included in the annex.
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Patel, Darshna K., Devayani R. Tipre, and Shailesh R. Dave. "Enzyme mediated bacterial biotransformation and reduction in toxicity of 1:2 chromium complex AB193 and AB194 dyes." Journal of the Taiwan Institute of Chemical Engineers 77 (August 2017): 1–9. http://dx.doi.org/10.1016/j.jtice.2017.02.027.
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Adams, C. D., W. Fusco, and T. Kanzelmeyer. "Ozone, Hydrogen Peroxide/Ozone And UV/Ozone Treatment Of Chromium- And Copper-Complex Dyes: Decolorization And Metal Release." Ozone: Science & Engineering 17, no. 2 (January 1995): 149–62. http://dx.doi.org/10.1080/01919519508547543.
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Pikaev, A. K. "Mechanism of radiation purification of polluted water and wastewater." Water Science and Technology 44, no. 5 (September 1, 2001): 131–39. http://dx.doi.org/10.2166/wst.2001.0269.
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The paper summarizes the results of the studies on radiation purification of polluted water and wastewater conducted in the author's laboratory in cooperation with other institutions. The removal of heavy metals (cadmium, lead, chromium and mercury) from water and wastewater, the purification of wastewater from surfactant and petroleum products, molasses distillery slops, municipal wastewater in the aerosol flow, river water from colored natural organic pollutants, wastewater of dyeing complex and paper mill, the decomposition of some dyes, hydrogen peroxide, chlorine-containing organic compounds, formic acid, etc. were investigated in detail. As a rule, electron-beam treatment in combination with ordinary methods (biological, coagulation, adsorption, flotation, etc.) was used. The main attention is paid to the mechanism of purification of the studied systems. The role of redox reactions of primary products of water radiolysis and secondary short-lived species formed from pollutants, formation of precipitates capturing the pollutants etc. is discussed.
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BONDARYEVA, Аnna, and Оlena MOKROUSOVA. "THE APPLICATION OF HYBRID PIGMENTS IN THE FORMATION OF A POLYMER-MINERAL COATING FOR LEATHER FINISHING." Herald of Khmelnytskyi National University. Technical sciences 315, no. 6 (December 29, 2022): 25–31. http://dx.doi.org/10.31891/2307-5732-2022-315-6(2)-25-31.
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The paper is focused to the study of the physical and mechanical properties of a polymer-mineral coating based on hybrid pigments for leather finishing. The aim of this research is to study the effect of hybrid pigments based on montmorillonite on the formation of a polymer-mineral coating for leather finishing. Hybrid pigments obtained by complex modification of native montmorillonite with sodium carbonate and basic chromium (III) sulfate with further subsequent adsorption of anionic dyes on the cationic surface of the mineral particles were used for this research. A ready-made mixture of various structures film-formers, intended for the finishing of facial and polished leather was used as a film-former. For the leather finishing, coating paints were prepared in the form of polymer-mineral compositions by mixing hybrid pigments with a film-forming agent in the ratio, wt. part 1: 5. In this study it was calculated that montmorillonite consumption at the level of 1.5-2.0% in terms of the mass of montmorillonite from the mass of dry polymer residue was optimal for obtaining high physical and mechanical properties of polymer films for finishing leather. A mechanism for structuring the polymer matrix with a hybrid pigment was proposed. According to this mechanism the highly developed sorption surface of montmorillonite provided adsorption of the polymer and stabilized its structure with the formation of a mixed polymer-mineral composite. It was shown that the use of montmorillonite in the composition of hybrid pigment allowed to adjust the physical and mechanical properties of the polymer-mineral composition for leather finishing, provided an increase in strength and regulated the level of elasticity of the covering film, which ensured an increase in the operational properties of the leather coating.
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Hauwa, H., S.A. Adamu, and Yakubu H. "Isolation and Identification of Bacteria from Soil Contaminated With Textile Dye And Tannery Effluents In Sokoto Metropolis." UMYU Journal of Microbiology Research (UJMR) 8, no. 1 (June 30, 2023): 134–42. http://dx.doi.org/10.47430/ujmr.2381.017.
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Soil contamination by textile and tannery effluents is a great concern to the environment, Complex effluents having a number of dyes accumulate in the soil there by polluting the environments and loss of microbial species in the soil. Samples were collected and the physicochemical analyses was determined. The pH was basic with 8.0 and 10.1 from tannery and dyeing site respectively. The organic carbon was very low with 0.76% and 0.06%, Nitrogen (0.067% and 0,095%), phosphorus 0.8mg/kg, and 1.62mg/kg), calcium (1.35mol/kg in both the two samples. Magnesium recorded 0.30mol/kg and 1.65mol/kg, potassium 0.85 mol/kg1.65mol/kg , Sodium 3.13mol/kg and 30.0 mol/kg in tannery and dyeing site respectively. The sand, silt and clay recorded (78.8% and 90.6%)(7.3% and 5.3%), (13.9% and 4.1%). The heavy metal content of the soil sample were determined the concentration of chromium was 0.0258 and 0.0043 from tannery and dyeing site respectively, while Nickel was almost unavailable in the site with -1.0700 and -1.0756. Lead recorded a very low concentration with -0.9164 and -7803. Thirteen bacterial species were isolated and identified based on morphology and biochemical charachteristics from the samples, tannery soil with frequency occurrences of 23.07% for Bacillus laterosporus, 15.38% for Bacillus subtilis and Bacillus megaterium while Bacillus firmus, Bacillus cereus, proteus vulgaris, proteus mirabilis and clostridium had 7.69% each. Fifteen species were isolated from the dyeing soil sample with Bacillus subtilis, Bacillus megaterium, and Pseudomonas aeruginosa with the highest frequency of occurrences with13.33% each. Burkholderia cepacia, P. florescense, Bacillus laterosporus,Bacillus amyloliquifeciens, Bacillus brevis and Proteus vulgaris had 6.66% each, all these were determine with the use of Microgen identification kit, molecular analysis was done on two bacterial isolates and were confirmed to be Alishwanella solinqauinati and Bacillus subtilis. These indicate that the species isolated can resist high amount of toxic chemicals and can withstand any harsh environment and hence their ability to serve as a potential biosorbents for bioremediation of the affected environments at a cheap cost.
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Ghosh, Arpita, Manisha Ghosh Dastidar, and Trichur Ramaswamy Sreekrishnan. "Bioremediation of a Chromium Complex Dye UsingAspergillus flavusandAspergillus tamarii." Chemical Engineering & Technology 39, no. 9 (August 15, 2016): 1636–44. http://dx.doi.org/10.1002/ceat.201500515.
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Ghosh, Arpita, Manisha Ghosh Dastidar, and T. R. Sreekrishnan. "Biosorption and Biodegradation of Chromium Complex Dye Using Aspergillus Species." Journal of Hazardous, Toxic, and Radioactive Waste 18, no. 4 (October 2014): 04014022. http://dx.doi.org/10.1061/(asce)hz.2153-5515.0000230.
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ZHAO, G., M. LI, Z. HU, and H. HU. "Dissociation and removal of complex chromium ions containing in dye wastewaters." Separation and Purification Technology 43, no. 3 (June 2005): 227–32. http://dx.doi.org/10.1016/j.seppur.2004.11.005.
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Anandhavelu, Shanmugam, and Sivalingam Thambidurai. "Preparation of an ecofriendly chitosan-ZnO composite for chromium complex dye adsorption." Coloration Technology 129, no. 3 (February 14, 2013): 187–92. http://dx.doi.org/10.1111/cote.12016.
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Pająk, Magdalena, Agnieszka Dzieniszewska, Joanna Kyzioł-Komosińska, and Michał Chrobok. "Use of metallurgical dust for removal chromium ions from aqueous solutions." E3S Web of Conferences 28 (2018): 01029. http://dx.doi.org/10.1051/e3sconf/20182801029.
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The aim of the study was to determine the potential for the application of dust from steel plant as an effective sorbent for removing Cr(III) and Cr(VI) in the form of simple and complex ions – Acid Blue 193 dye from aqueous solutions. Three isotherms models were used to interpret the experimental results namely: Langmuir, Freundlich, and Dubinin–Radushkevich. Estimated equations parameters allowed to determine the binding mechanism. Based on laboratory studies it was found that the dust was characterized by high sorption capacities for Cr ions and dye from the aqueous solution. The sorption capacity of the dust for Cr(III) and Cr(VI) ions depended on the degree of oxidation, pH of solution and kind of anion and changed in series: Cr(III)-Cl pH=5.0> Cr(III)-SO4 pH=5.0> Cr(III)-Cl pH=3.0> Cr(III)-SO4 pH=3.0> Cr(VI) pH=5.0> Cr(VI) pH=3.0. Dust was also characterized by a high maximum sorption capacity of dye at a range of 38.2 – 91.7 mg/g, depending on the dose of dust. Based on the study it was found that dust from a steel plant, containing iron oxides, can be used as low-cost and effective sorbent to remove pollutions containing chromium ions, especially from acidic wastewater.
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Lee, Seul, Jae-Hwan Kim, Kwangmin Na, Seung Min Yang, Dong Kwon Kim, Sujeong Baek, Seong-san Kang, et al. "Abstract 6780: Characterization of immunological heterogeneity in the tumor microenvironment by integrated analyses using single cell RNAseq, spatial RNAseq and multiplex IHC." Cancer Research 83, no. 7_Supplement (April 4, 2023): 6780. http://dx.doi.org/10.1158/1538-7445.am2023-6780.
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Abstract Heterogeneity in resistant to immunotherapies of tumor microenvironment (TME) has been implicated in immunotherapies to cause immune evasion or drug resistance. This study was conducted to explore the heterogeneity of TME through multiplex IHC, spatial and RNA sequencing analysis. We selected a sample from a lung adenocarcinoma patient without EGFR-activating mutation and expressing 30% of PD-L1. For quantitative analysis by multiplex IHC, various markers including CD4, CD8, FoxP3, granzyme B, CD20 and pan-cytokeratin were stained with 7 different fluorescence dyes, which was imaged with Vectra Polaris (Akoya). For scRNAseq and spatial RNAseq, we used 5’ chromium library kit (10X Genomics) to make library construction. Integrated raw data was generated using Cell ranger, Seurat pipeline and Azimuth package. The tumor area was divided into 16 clusters in which we selected 2 clusters based on CD3/45 expression. There was a noticeable distinction between the two clusters which were defined as the ‘High’ region (CD45highCD3high cluster) and the ‘Low’ region (CD45lowCD3low cluster). By multiplex IHC, percentage of CD8+T cells was higher in the ‘High’ region than in the ‘Low’ region (8.5% vs. 0.8%, respectively). Subsequent analysis of two clusters using spatial and single cell RNA seq, the ‘Low’ region was characterized by increased hypoxia-associated gene expressions including HIF1A, HIF3A and VEGFA. Various immune cells were abundant in the ‘High’ region and CD45 expression level was 11-fold higher in the ‘High’ region compared to the ‘Low’ region. Cytokine/chemokine network analysis via spatial RNAseq revealed that gene expression of tumor necrosis factor (TNF) family-associated factors increased in the 'High' region compared to the ‘Low’ region (TNF, FAS, TRAIL, RANKL and CD40), which is well-known to promotes apoptosis, programmed cell death, or necrosis of certain cancer. Additionally, the ‘High’ region also had elevated levels of the PD-1/PD-L1, CD155, CD122/TIGIT, Siglec10/CD24, LAG3/LAGLS3, and CD47/CD172a axes, suggesting active immune responses. Intriguingly, combined analyses showed that ‘High’ region showed enhanced level of CD44 expression as the leading-edged gene, which suggests the metastatic potential of tumor cells. Furthermore, scRNA analysis confirmed that CD44 expression was mainly higher in macrophages, suggesting that tumor-associated macrophages partially affected tumor cell metastasis in the ‘High’ region. Our finding suggests that understanding the intratumoral immunological heterogeneity of lung adenocarcinoma can help to study the mechanism of tumor heterogeneity by integrated spatial RNAseq and scRNAseq analyses. This type of technique could be applied to understand complex networks of anti-tumor immune activities, drug resistance mechanisms and immunotherapeutic response of cancer. Citation Format: Seul Lee, Jae-Hwan Kim, Kwangmin Na, Seung Min Yang, Dong Kwon Kim, Sujeong Baek, Seong-san Kang, Yu Jin Han, Chun-Bong Synn, Mi hyun Kim, Heekyung Han, Young Taek Kim, Sungwoo Lee, Youngseon Byeon, Young Seob Kim, Ji Yun Lee, Jii Bum Lee, Chang Gon Kim, Min Hee Hong, Sun Min Lim, Kyoung-Ho Pyo, Byoung Chul Cho. Characterization of immunological heterogeneity in the tumor microenvironment by integrated analyses using single cell RNAseq, spatial RNAseq and multiplex IHC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6780.
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Steenfelt, Agnete, Julie A. Hollis, and Karsten Secher. "The Tikiusaaq carbonatite: a new Mesozoic intrusive complex in southern West Greenland." Geological Survey of Denmark and Greenland (GEUS) Bulletin 10 (November 29, 2006): 41–44. http://dx.doi.org/10.34194/geusb.v10.4905.
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Ultrabasic alkaline magmatic rocks are products of melts generated deep within or at the base of the lithospheric mantle. The magmas may reach the surface to form lavas and pyroclastic deposits; alternatively they crystallise at depth to form dykes or central complexes. The rocks are chemically distinct and may contain high concentrations of economically interesting minerals and chemical elements, such as diamonds, niobium, tantalum, rare earth elements, phosphorus, iron, uranium, thorium, and zirconium. Ultrabasic alkaline rocks are known from several provinces in Greenland, but extrusive facies have only been preserved at a few places; e.g. at Qassiarsuk in South Greenland where pyroclastic rocks occur, and in the Maniitsoq region, where a small volcanic breccia (‘Fossilik’) contains fragments of Palaeozoic limestone. Ultramafic lamprophyre and kimberlite are mainly emplaced as dykes, whereas carbonatite forms large intrusive bodies as well as dykes. The ultrabasic alkaline magmas that have been emplaced at certain times during the geological evolution of Greenland can be related to major episodes of continental break-up (Larsen & Rex 1992). The oldest are Archaean and the youngest dated so far are Palaeogene. Figure 1 shows the distribution of known ultrabasic alkaline rocks in West Greenland. The large and well-exposed bodies of alkaline rocks and carbonatites in the Gardar Province were discovered already in the early 1800s (Ussing 1912), while less conspicuous bodies were discovered much later during geological mapping and mineral exploration. Many alkaline rock bodies, particularly dykes, are difficult to identify in the field because they weather more extensively than the country rock gneisses and form vegetated depressions in the landscape. However, their distinct chemistry and mineralogy render alkaline rocks identifiable in geochemical and geophysical survey data. Thus, the Sarfartôq carbonatite complex was discovered during regional airborne gamma-spectrometric surveying owing to its elevated uranium and thorium contents (Secher 1986). The use of kimberlite indicator minerals has led to the discovery of alkaline rocks such as kimberlites and ultramafic lamprophyres that carry fragments of deep lithospheric mantle. Such rocks may also contain diamonds. Kimberlite indicator minerals are high-pressure varieties of minerals, such as garnet, clinopyroxene, chromite and ilmenite that were formed in the lithospheric mantle. Exploration companies have processed thousands of till samples from southern West Greenland for kimberlite indicator minerals and found many new dykes.
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Gutierrez, A. R., Arthur Diaz, and B. Baird. "Solubility, dispersion, and carbon adsorption of a chromium hydroxyazo complex dye in a styrene-butyl methacrylate copolymer." Langmuir 7, no. 9 (September 1991): 1923–27. http://dx.doi.org/10.1021/la00057a018.
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binti Rosli, Nurul Najihah, Lim Chee Ming, Abdul Hanif Mahadi, Suthee Wattanasiriwech, Ren Chong Lim, and N. T. R. N. Kumara. "Ruthenium Dye (N3) Removal from Simulated Wastewater Using Bamboo Charcoal and Activated Bamboo Charcoal." Key Engineering Materials 765 (March 2018): 92–98. http://dx.doi.org/10.4028/www.scientific.net/kem.765.92.
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The presence of heavy metals such as mercury (Hg), cadmium (Cd), arsenic (As), chromium (Cr), thallium (T1) and ruthenium (Ru) in wastewater, even in trace quantities, could cause a negative impact on our health. The adsorption method has been proven to be the most effective and low-cost method for removing of heavy metals from wastewater. In this study, biomass waste was used as a low-cost precursor for the production of cost-effective charcoal and activated carbon. Solid waste from a common local bamboo species (Gigantochloa sp.) was used to produce charcoal and activated carbon. The simulated wastewater was made with Ruthenium complex (N3) dye solution as the adsorbate. The bamboo charcoal was prepared by carbonization, and activated carbon was prepared by NaOH activation after carbonization. The morphological characteristics, chemical compositions, and the lattice structures of the prepared adsorbents were analyzed using SEM, EDX, and XRD. The adsorption performance of the prepared adsorbents toward N3 dye was evaluated, and the highest adsorption capacity of 1.50 mg/g was obtained from activated carbon. The results showed that the activated bamboo-based charcoal has a better adsorption efficiency when compared to the bamboo charcoal for the treatment of N3 dye in wastewater.
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Norris, D. A., S. B. Ryan, R. M. Kissinger, K. A. Fritz, and S. T. Boyce. "Systematic comparison of antibody-mediated mechanisms of keratinocyte lysis in vitro." Journal of Immunology 135, no. 2 (August 1, 1985): 1073–79. http://dx.doi.org/10.4049/jimmunol.135.2.1073.
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Abstract We have conducted a systematic comparison of lysis of TNP-coated keratinocyte targets by TNP-specific antibody, by antibody plus complement, by antibody-dependent cellular cytotoxicity (ADCC), and by natural killing with the use of monocyte, lymphocyte, and neutrophil effectors. With chromium-release assays, human keratinocytes, HEp-2 cells (transformed human keratinocytes), PAM 212 cells (transformed mouse keratinocytes), and RSC (transformed rabbit keratinocytes) were all susceptible to monocyte- and lymphocyte-mediated ADCC (p less than 0.01 to p less than 0.02). All trypsinized keratinocyte targets were also susceptible to natural killing by monocyte or lymphocyte effectors (p = 0.05 to p less than 0.001). Antibody and antibody plus complement were poor mediators of keratinocyte lysis. If protein and complex lipid synthesis of keratinocytes were inhibited by 16-hr cycloheximide preincubation, then keratinocytes were susceptible to complement-mediated lysis, implying that the resistance of these cells to complement may be due to repair of transmembrane pores. Comparison of chromium-release assays with fluorescein diacetate dye uptake viability assays showed that human keratinocytes were still susceptible to monocyte and lymphocyte ADCC but not to antibody, antibody plus complement, or natural killing. The reproducible and uniform susceptibility of normal and transformed keratinocyte targets from three different species to monocyte and lymphocyte ADCC supports the hypothesis that this mechanism of cellular lysis may be important in antibody-associated diseases of epidermal cytotoxicity.
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Rogkala, A., P. Petrounias, B. Tsikouras, and K. Hatzipanagiotou. "PETROGENETIC SIGNIFICANCE OF SPINELS FROM SERPENTINISED PERIDOTITES FROM THE VERIANAOUSA OPHIOLITE." Bulletin of the Geological Society of Greece 50, no. 4 (July 28, 2017): 1999. http://dx.doi.org/10.12681/bgsg.11946.
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The Veria-Naousa ophiolitic complex represents a dismembered ophiolite unit, which is superimposed on a basement consisting of rocks belonging to the Pelagonian and Axios (Almopias subzone) isopic zones in northern Greece. Mantle peridotites are composed of variably serpentinised lherzolite and harzburgite intruded by a sparse network of pyroxenitic dykes. The serpentinised lherzolite and harzburgite contain Alspinels (Cr#=38.83-42.52 and Mg#=58.94-64.77), Cr-spinels (Cr#=43.37-64.92 and Mg#=49.20-58.66) and magnesiochromites (Cr#=53.93 57.13 and Mg#=55.73- 61.71). All of them display commonly richer-in-Cr cores rimmed by secondary ferrian chromite and magnetite. Whole-rock geochemicall compositions and primary spinel chemical composition of these peridotites are analogous to peridotites that formed in a suprasubduction zone. Ιt is supported that the Mantle peridotites of the VeriaNaousa ophiolitic complex formed in a back-arc basin
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Delor, C. P., and N. M. S. Rock. "Alkaline-ultramafic lamprophyre dykes from the Vestfold Hills, Princess Elizabeth Land (East Antarctica): primitive magmas of deep mantle origin." Antarctic Science 3, no. 4 (December 1991): 419–32. http://dx.doi.org/10.1017/s0954102091000512.
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Alkaline dykes tentatively dated at ∼1.3 Ga cut the Vestfold Hills in a consistent N–S to N15°E direction. They form a spectrum between more abundant ultramafic lamprophyres (UML) corresponding broadly to H2O–CO2-rich nephelinites, and alkaline lamprophyres (AL), representing H2O–CO2-rich basanites. Olivine (Fo46–93, averaging Fo75) is abundant only in the UML, but both types carry primary diopsidic clinopyroxene with complex zoning; amphibole (pargasite, hastingsite, kaersutite with up to 8.6% TiO2); titanian phlogopite (up to 10% TiO2); feldspars (orthoclase, anorthoclase, albite and andesine), nepheline (K-poor and Si-rich), ilmenite (up to 1% MgO and MnO), chrome titanomagnetite, and carbonate (magnesian calcite, ferroan dolomite, breunnerite). Lamprophyric peculiarities include the local coexistence of three feldspars, extremely Ti-rich amphiboles and micas, and the presence of globular structures and possibly primary carbonates. Some dykes carry small but abundant lherzolite xenoliths, others carry chromian diopside (1% Cr2O3) and En58–76 orthopyroxene xenocrysts. The dykes represent primitive, mantle-derived magmas which have undergone varying but generally low degrees of polybaric fractionation, together perhaps with mixing of more primitive and fractionated batches, during their ascent through the crust.
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Arslan-Alaton, Idil, B. Hande Gursoy, Abdurahman Akyol, Mehmet Kobya, and Mahmut Bayramoglu. "Modeling and optimization of acid dye manufacturing wastewater treatment with Fenton's reagent: comparison with electrocoagulation treatment results and effects on activated sludge inhibition." Water Science and Technology 62, no. 1 (July 1, 2010): 209–16. http://dx.doi.org/10.2166/wst.2010.256.
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In the present study, Fenton's oxidation of a chromium complex disazo dye (Acid Blue 193) synthesis wastewater was evaluated, modeled and optimized by employing Central Composite Design. Within this context, the individual and interactive effects of critical process parameters such as Fe2 + , H2O2 concentrations, initial chemical oxygen demand (COD) and reaction time was assessed. The process response (output) variables were chosen as percent color, COD and total organic carbon (TOC) removal efficiencies. Optimum working conditions in terms of color and organic carbon removals were established to be Fe2 + = 3 mM; H2O2 = 25 mM; reaction time = 10 min at pH 3 and an initial COD content of 245 mg/L. Under these conditions, 96% color, 82% COD and 51% TOC removals were obtained. The established polynomial regression models describing color, COD and TOC removals satisfactorily fitted the experimental data and could be used to predict Fenton's treatment results at statistically significant rates. Optimized treatment results were compared with those obtained via electrocoagulation treatment under optimized conditions (applied current = 50 A/m2; reaction time = 15 min; initial pH = 7 for an initial COD content of 245 mg/L). The relative inhibition of heterotrophic oxygen uptake rate was measured to examine the inhibitory effect of azo dye synthesis effluent before and after Fenton's oxidation and electrocoagulation with respect to synthetic domestic wastewater. Untreated azo dye production wastewater exhibited a slightly inhibitory effect that was appreciably reduced but not entirely removed after Fenton's oxidation, whereas no inhibition of mixed bioculture was observed for azo dye synthesis effluent subjected to electrocoagulation treatment.
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Santharam, A., and Kandula Vishnu Vardhana Rao. "Geotechnical Investigations - A Tool for Deciding Mining Method for Chromite Deposits in Odisha State, India." Global Journal of Earth Science and Engineering 4 (December 31, 2017): 27–35. http://dx.doi.org/10.15377/2409-5710.2017.04.4.
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The Chromite deposits of Sukinda valley, Odisha, India are of strategic importance for the development of ferro-alloy industries. Around 90% of the India’s chromite ore production derived from two important chromite bearing belts, namely the Baula-Nuasahi belt and Sukinda valley ultramafic complex deposit. In terms of rock strength properties, the host rocks and ore body at Baula – Nuasahi chromite belt are hard and compact, with some structural defects such as joints, faults and dykes. After extracting the chromite ore by surface mining up to the economic pit bottom, the remaining reserves were being mined by underground method. In the Sukinda valley chromite deposits, both the wall rocks and ore body are weak, highly weathered. These mines were operated by opencast method. As most of the working mines in Sukinda valley reached their economic pit limit and there is no further scope to extract the ore by opencast mining. Since the chromite ore bodies are having considerable mineable strike length, width, and depth persistence, there is no option except to convert them into underground mines to increase the life of the mines. The chromite ore bodies were proved up to depth of 270m by exploratory drilling. Some major mining companies are planning for underground mining operations, due to constraint of limited space available for waste dumping, working with common lease boundary, slope instability, high volume of stripping ratio. To overcome such problems, the basic step is to conduct the detailed geo-technical investigations to avoid any unexpected consequences during mine development and stoping operations. The geo-technical investigations comprised of geotechnical mapping of existing mined out benches using scan line surveys, geo-technical drilling and logging of cores for the estimation of RQD, structural discontinuities, testing of cores for material properties followed by performing numerical modeling to evolve a suitable stoping method and excavation geometry. The paper deals with the results of the geo-technical investigations carried out for the planning and design of underground mine workings, design of stope parameters based on the geo-mining conditions.
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Kaušpėdienė, D., E. Kazlauskienė, A. Gefenienė, and R. Binkienė. "Comparison of the efficiency of activated carbon and neutral polymeric adsorbent in removal of chromium complex dye from aqueous solutions." Journal of Hazardous Materials 179, no. 1-3 (July 2010): 933–39. http://dx.doi.org/10.1016/j.jhazmat.2010.03.095.
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Serov, Pavel A., Tamara B. Bayanova, Ekaterina N. Steshenko, Evgeniy L. Kunakkuzin, and Elena S. Borisenko. "Metallogenic Setting and Evolution of the Pados-Tundra Cr-Bearing Ultramafic Complex, Kola Peninsula: Evidence from Sm–Nd and U–Pb Isotopes." Minerals 10, no. 2 (February 19, 2020): 186. http://dx.doi.org/10.3390/min10020186.
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The article presents new Sm–Nd and U–Pb geochronological data on rocks of the poorly studied Pados-Tundra Cr-bearing complex. It is part of the Notozero mafic–ultramafic complex (western Kola Peninsula) and occurs at the border of the Paleoproterozoic Lapland Granulite Belt and the Archean Belomorian composite terrain. The Pados-Tundra complex hosts two major zones, the Dunite and Orthopyroxenite Blocks. Dunites are associated with four levels of chromite mineralization. Isotope Sm–Nd studies of dunites, harzburgites, and orthopyroxenites from the central part of the complex have been carried out. The isochron Sm–Nd age on 11 whole-rock samples from a rhythmically layered series of the complex is 2485 ± 38 Ma; the mineral Sm–Nd isochron for harzburgites shows the age of 2475 ± 38 Ma. It corresponds with the time of large-scale rifting that originated in the Fennoscandian Shield. When the rhythmically layered series of the intrusion and its chromite mineralization were formed, hornblendite dykes intruded. The U–Pb and Sm–Nd research has estimated their age at ca. 2080 Ma, which is likely to correspond with the occurrence of the Lapland–Kola Ocean. According to isotope Sm–Nd dating on metamorphic minerals (rutile, amphibole), the age of postmetamorphic cooling of rocks in the complex to 650–600 °C is 1872 ± 76 Ma. The U–Pb age on rutile from a hornblendite dyke (1804 ± 10 Ma) indicates further cooling to 450–400 °C. The conducted research has determined the early Proterozoic age of rocks in the rhythmically layered series in the Pados-Tundra complex. It is close to the age of the Paleoproterozoic ore magmatic system in the Fennoscandian Shield that developed 2.53–2.40 Ga ago. Later episodes of alterations in rocks are directly related to main metamorphic episodes in the region at the turn of 1.9 Ga. Results of the current study expand the geography of the vast Paleoproterozoic East Scandinavian Large Igneous Province and can be applied for further studies of similar mafic–ultramafic complexes.
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ARNASON, JOHN G., DENNIS K. BIRD, STEFAN BERNSTEIN, NICHOLAS M. ROSE, and CRAIG E. MANNING. "Petrology and geochemistry of the Kruuse Fjord Gabbro Complex, East Greenland." Geological Magazine 134, no. 1 (January 1997): 67–89. http://dx.doi.org/10.1017/s0016756897006389.
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The Kruuse Fjord Gabbro Complex is a composite intrusion of layered gabbro and troctolite with subordinate ultramafic rocks and minor trondhjemitic bodies. It was emplaced into Archaean continental crust of East Greenland during early Tertiary rifting of Greenland from Eurasia. The work to date has identified an outer gabbro series and an inner troctolite series, and these are separated by a narrow zone of trondhjemitic intrusions. In the southeast, the partially crystallized cumulates of the gabbro series were intruded by a lenticular, ultramafic pluton 800 m in thickness. Volumetrically minor, syenite–trachyandesite net-veined dykes and later, diabase dykes cross-cut the plutonic rocks. Structural and topographic features suggest that the layered rocks were affected by synmagmatic subsidence and deformation but not by monoclinal coastal flexure.The gabbro series is composed of a marginal gabbro unit, about 20 m wide, bordering more than a 2 km thickness of layered olivine and magnetite gabbro cumulates. The marginal gabbro is interpreted to be chilled magma. The layered cumulates are the product of repeated injections of magma that fractionated in an open-system magma chamber. Anorthositic and troctolitic layers in the lower part of the sequence may represent inputs of magma and suggest that the order of cumulus mineral crystallization was (1) plagioclase (An39–85), (2) olivine (Fo46–82), (3) augite (Wo28–47En39–58Fs8–18 ) and (4) magnetite. The disappearance of cumulus magnetite and a reversal in mineral compositions at 1.5 km from the base of the succession suggests a major input of magma occurred at this height. In the troctolite series, the composition of cumulus minerals, mineral crystallization sequence and style of emplacement are similar to those in the gabbro series. The ultramafic pluton is composed of coarse-grained wehrlite, olivine melagabbro and troctolite that were formed by at least three injections of magma. The typical mineral crystallization sequence was (1) cumulus chromite and olivine (Fo84–88); (2) poikilitic chrome diopside (Wo29–51En43–63Fs3–13 ); and (3) intercumulus plagioclase (An75–90), phlogopite, apatite and localized disseminated sulphides containing Au and platinum-group elements.Comparison of crystallization sequences and the major and trace element compositions of clinopyroxene suggests that the gabbroic and troctolitic rocks formed from a magma represented by the chilled marginal gabbro, a tholeiitic basalt magma similar to E-MORB, whereas the ultramafic rocks formed from a magma that was relatively enriched in incompatible trace elements and volatiles. The association of these two magma types is an example of bimodal mafic–ultramafic magmatism in a rifting environment.
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Smol’kin, Valery F., and Artem V. Mokrushin. "Paleoproterozoic Layered Intrusions of the Monchegorsk Ore District: Geochemistry and U–Pb, Sm–Nd, Re–Os Isotope Analysis." Minerals 12, no. 11 (November 11, 2022): 1432. http://dx.doi.org/10.3390/min12111432.
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The paper concerns the geochemical analysis of rocks from the ore-bearing layered intrusions that belong to two age groups of the Monchepluton and the Imandra–Umbarechka Complex (2.50 and 2.44 Ga) and the largest gabbro-anorthosite of the Main Ridge Complex (2.51–2.45 Ga). The intrusion of these complexes happened at different depths when the endogenous and geodynamic settings changed at the beginning of the Paleoproterozoic Era. Five megacycles are distinguished in a generalized cross-section of the two-chamber Monchepluton. The megacycles differ in rock composition, rock geochemical features, and mineralization types, i.e., the chromite, sulfide Cu–Ni–PGE and low-sulfide PGE types. The abrupt changes in isotope indicators (εNd, 87Sr/86Sr) mark their boundaries. At a depth of 2037–2383 m, the M-1 borehole intersects a standalone intrusive body that is essentially a magma feeder channel. The intrusive body’s geochemical characteristics and U–Pb isotope age correlate to the Monchepluton rocks. The gabbro-anorthosite massifs united in the Main Ridge Complex were intruded in the following order: the Monchetundra, Chunatundra, Volchetundra, and Losevo–Medvezhye tundras. The largest Monchetundra massif was formed as a result of multiple intrusions of mafic magmatic melt from the deep reservoirs. The melts intruded in two stages, i.e., 2.51–2.49 Ga and 2.48–2.47 Ga, and their composition changed gradually. The gabbro-pegmatites and coeval harrisite dykes are more recent ones (2.46–2.45 Ga). The summarized results of the U–Pb, Sm–Nd, and Re–Os systems research allowed us to establish genetic relations between the studied geological objects. We proposed a model where there was an uplift of a mantle plume to the lower crust area at the age of 2.5 Ga, the deep mantle reservoirs were formed, and a large-scale interaction happened between the parental magma and granulite–eclogite complex rocks. Local contamination and assimilation processes took place during the uplifting of magmas in areas where the magmatic feeding system contacted the host amphibolite–gneiss Archean complexes.
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Kuzin, Evgenii N., Tatyana I. Nosova, and Natalya E. Kruchinina. "ENVIRONMENTALLY SAFE TECHNOLOGY FOR SYNTHESIZING TITANIUM TRICHLORIDE FOR THE NEEDS OF VARIOUS INDUSTRIES." Siberian Journal of Life Sciences and Agriculture 14, no. 4 (August 30, 2022): 23–35. http://dx.doi.org/10.12731/2658-6649-2022-14-3-23-35.
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The authors have assessed the possibility of electrochemical synthesis of a wide range of reagents based on titanium trichloride as part of the work. Despite the growing demand for titanium trichloride and its derivatives, the production technology of this reagent has not been improved for a long period. Traditional technologies feature high environmental and industrial hazards, and the process itself has high energy consumption and a complex hardware scheme. As part of preliminary work, the possibility of obtaining titanium trichloride from aqueous solutions of titanium tetrachloride is established, while the proposed technology is distinguished by reduced energy consumption and safety. At the first stage of experiments in the anodic dissolution of aluminum, binary solutions of titanium trichloride and aluminum chloride are obtained. The degree of conversion TiCl4 → -TiCl3 is 65%–35% for a current density of 10–30 A/dm2, respectively. In the process of reducing an aqueous solution of titanium tetrachloride with iron electrodes, the yield of titanium trichloride is approximately 76%–66% for a current density of 10–30 A/dm2, respectively. The resulting solution is heavily contaminated with iron (II) compounds. The results of the experiments show the high efficiency of this solution in the processes of purification of wastewater from galvanic production from chromium (VI) compounds. For the production of high-purity titanium trichloride, titanium electrodes are used, while the yield of titanium trichloride is 59%–3% for a current density of 10–30 A/dm2, respectively. Depending on the production technology and electrode material, solutions are obtained that can be used to produce high-purity titanium dioxide for the production of dye-sensitized solar cells, reagents for water purification, and a Ziegler-Natta catalyst and a reagent for organic synthesis.
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Emeleus, C. H., and V. R. Troll. "The Rum Igneous Centre, Scotland." Mineralogical Magazine 78, no. 4 (August 2014): 805–39. http://dx.doi.org/10.1180/minmag.2014.078.4.04.
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AbstractThe publication of the British Geological Survey memoir on Rum and the Small Isles in 1997 was followed by a period of intense petrological and mineralogical research, leading to some 40 papers, books and other publications. The research progress since then is reviewed here and integrated with the information previously available to provide an overview of the current status of understanding of the centre. New data on the acidic and mixed acid/basic magmas of the early Rum caldera demonstrate that frequent mafic replenishments were the main driver for magmatic activity at Rum right from its initial stages. The caldera is bound by the Main Ring Fault, a structure which probably also exercised an influence on the emplacement of the subsequent basic and ultrabasic intrusions. The later emplacement of gabbros and ultrabasic rocks caused only limited thermal metamorphism of the surrounding Torridonian sandstones, contrasting markedly with the crustal isotope signatures of the early intracaldera ignimbrite magmas and the intense alteration of uplifted masses of Lewisian gneiss within the ring fault. Rare picritic dykes provide an indication of the possible parent magma for the mafic and ultrabasic rocks, but these, as with most other magmatic rocks on Rum, have undergone varying degrees of crustal contamination, involving both Lewisian granulite and amphibolite-type crust but, notably, no Moine metasedimentary compositions as is the case at the nearby Ardnamurchan centre. Detailed textural studies on the gabbroic and ultrabasic rocks allow a distinction between intrusive peridotites and peridotite that forms part of the classic layered cumulate units of Rum and, furthermore, this work and that on the chromite seams and veins in these rocks shows that movement of trapped magma and magma derived from later intrusions, may produce textures regarded previously as of primary cumulate origin. Sulfides in the chromitite seams and ultrabasic rocks, in turn, show possible influences from assimilated Mesozoic sediments. Igneous activity on Rum was short-lived, possibly only between 0.5 and 1 m.y. in duration and commenced at ∼60.5 Ma. The Rum Central Complex was extinct by the time the main activity at the nearby Skye Central Complex commenced (∼59 Ma). From recent apatite fission-track studies it seems probable that Rum, in common with other Palaeogene centres, underwent a brief, but significantly later heating event (∼45 Ma).
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Kebede, Fasika. "Removal of Chromium and Azo Metal-Complex Dyes Using Activated Carbon synthesized from Tannery Wastes." Open Access Journal of Science and Technology 05, no. 02 (2017). http://dx.doi.org/10.11131/2017/101214.
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Povar, Igor, Boris Pintilie, and Oxana Spînu. "Indirect chronovoltametric dosage of alkaline earth metals. The contribution of the chemist Ion Vatamanu to the development of electrochemical methods of analysis." Akademos, no. 1(64) (June 2022). http://dx.doi.org/10.52673/18570461.22.1-64.10.
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The paper presents the results of a series of investigations on the indirect chronovoltametric dosing of alkaline earth metals, carried out in the Laboratory of the Analytical Chemistry at the Institute of Chemistry, currently called the Laboratory of Physicochemical Methods of Research and Analysis, conducted in 1971–1993 by the doctor of chemical sciences Ion Vatamanu. During the elaboration of the presented polarographic methods for determining the ions of alkaline-earth metals, a series of techniques were used to increase the sensitivity and selectivity of the determination. Based on two indirect polarographic methods for measuring alkaline earth metals, developed by Ion Vatamanu and coworkers and analyzed in this paper, two fundamental physicochemical principles were applied: (I) anion-induced adsorption of ligands adsorbed on the electrode surface and (II) thermodynamic determination of the optimal dosing conditions by calculating the conditional constants or the equilibrium chemical composition of complex reactant systems. The developed methods were used in the electrochemical analysis of standard alloy samples based on various metals, in the analysis of semiconductor systems, ferrous metals, nickel electrolytes, copper plating, cadmium plating, chromium plating, aluminum oxidation, wastewater analysis in galvanic baths, clays and limestones from Moldovan deposits, determination of pesticides, tanning extracts, dyes for the textile industry, etc.
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"Separation of Chromium Cadmium Nickel and Titanium from Ilmenite Ore." Advance in Environmental Waste Management & Recycling 3, no. 2 (June 20, 2020). http://dx.doi.org/10.33140/aewmr.03.02.12.
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This study shows the separation of chromium, cadmium, nickel and titanium from Egyptian ilmenite ore. The method implicates leaching the ore in 20% hydrochloric acid. Titanium ions, after removal of the ferrous ions, were precipitated as a hydroxide. It was reduced with 1 M alcoholic ascorbic acid. Chromium, cadmium, and nickel in the leachate were estranged by a strongly basic Lewatit 600 anion exchanger. The picked-up elements were eluted using 4M hydrochloric acid. An azo resorcinol 4-(2-pyridylazo) dye helps complexing of the adsorbed elements to form negatively charged complexes. Adsorption isotherms were modelled in an ethanol/acetic acid/water media. Results show that the convenient conditions of leaching the ore were 30% HCl for 120 min at 80°C, solid: liquid ratio of 1:30 and stirring. The interaction between the metal ions and the ion-exchanger to form the complex compounds is an electrostatically controlling-adsorption step. The trivalent chromium showed a significant perception at an acid medium at a pH 3.5-4.5. Cadmium and nickel ions uptake takes place in an alkaline medium. The chelating capacity of the sorbent is proportional to the electronegativity of the metal-dye complexes. The ∆E of the leaching process amounts to 13.8 kJ per mole.
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Doroshkevich, Anna, Ilya Prokopyev, Mikhail Kruk, Viktor Sharygin, Ivan Izbrodin, Anastasiya Starikova, Anton Ponomarchuk, Andrey Izokh, and Yazgul Nugumanova. "Age and petrogenesis of ultramafic lamprophyres of the Arbarastakh alkaline-carbonatite complex, Aldan-Stanovoy shield, South of Siberian Craton (Russia): evidence for ultramafic lamprophyre-carbonatite link." Journal of Petrology, July 28, 2022. http://dx.doi.org/10.1093/petrology/egac073.
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Abstract In this study, we discuss mineral chemistry data, melt inclusion study results, and report Ar-Ar phlogopite age for the aillikite dykes of the Arbarastakh alkaline-carbonatite complex on the Aldan-Stanovoy shield, Russia. Aillikite was crystallised at 631 ± 8.5 Ma, coeval with the intrusion age of the Arbarastakh rocks. The Arbarastakh complex was formed during the late Neoproterozoic epoch of REE-Nb ore-bearing alkaline-carbonatite magmatic activity that was widespread on the southwestern and southern margins of the Siberian craton, related to rifting processes during the breakup of the supercontinent Rodinia. The aillikites show mineralogical characteristics of primitive magmas such as highly forsteritic olivine, Mg-ilmenite, and Cr-rich spinel. The variance in olivine zonation, morphologies, and chemical element distribution indicate that olivine in the aillikites is represented by several genetic types: xenogenic olivines (Fe-poor cores) from the sheared peridotite; olivine antecrysts (Fe-rich cores) related to mantle metasomatism by preceding proto-aillikite melt; and olivine phenocrysts formed during crystallization of aillikite melt. The latter shows decreasing Ni and Cr due to fractional crystallization of olivine, ilmenite, and chromite; along with increasing Mn and Ca concentrations that are consistent with enrichment of these elements in the residual melt. The olivine phenocrysts chemistry shows variations that are characteristic of the presence of phlogopite and carbonate in the mantle source (low 100*Ca/Fe (0.4-1.2) and 100*Mn/Fe (1-2), moderate 100*Ni/Mg (1.4-0.4)). Spinel shows a wide compositional variation with two compositional zoning trends, one of which follows the titanomagnetite trend, while the other follows the qandilite-rich magnesio-ulvöspinel-magnetite one. The latter trend indicates an increase in fO2 and attendant Fe oxidation to Fe3+ during crystallization. Ilmenite composition evolution (from Mg-rich to Mn-rich) also reflects the carbonate-rich nature of aillikite melt. We identify primary melt inclusions hosted in phlogopite and secondary melt inclusions in olivine; both melt inclusions types have daughter minerals dominated by dolomite, calcite, Na-Ca carbonates, phosphates, and phlogopite, consistent with the carbonate-rich nature of aillikite melt. The calculated temperatures reflect the early stage of aillikite crystallization, with values ranging from 1169 to 1296°C and fO2 values (olivine-spinel pair) varying from +0.40 to +1.03 ΔFMQ, and from ΔNNO −0.9 to ΔNNO −2.0 (perovskite oxygen barometer); in contrast, the homogenization temperature of the secondary melt inclusions in olivine (700-720 °C) characterizes late-stage aillikite melt evolution. The carbonate-rich nature of the Arbarastakh aillikite and its similar age to the carbonatites are consistent with a genetic relationship between them.