Papers by Keyword: Nickel

Abstract: Nickel (Ni (II)), cobalt (Co (II)) and manganese (Mn (II)) are often encountered in wastewaters. These metals have been identified as micronutrients, at trace concentrations; however, they are microbial growth inhibitors, at relatively high concentrations. The present review discusses, in a systematic way, the individual effects of the above heavy metals to the growth of microorganisms grown under aerobic conditions, with focus on the growth of activated sludge.

Abstract: Structural features of laminated “nickel - nickel aluminide” composite materials obtained by SPS - sintering of alternately stacked nickel and aluminum foil, thickness 100 and 25 m respectively, have been investigated in this paper. The composition of diffusion layers formed due to the reaction between nickel and aluminum was studied using energy dispersive X-ray microanalysis and X-ray diffraction methods. It was found that phase composition of diffusion layers significantly depends on SPS - sintering temperature.

Abstract: This paper presents an experimental investigation into microfabrication of nickel template by femtosecond laser in air at atmospheric pressure. The laser pulses used for the study are 800 nm in wavelength, 100fs in pulse duration, and the repetition rate used is 1KHz. Micro-hole ablation experiments are carried out in air by focusing the femtosecond laser beam on the nickel target surface at normal incidence with the long-focus objective lens of enlargement factor 50 and NA=0.7. Dependence of the diameter, depth and depth-to-diameter ratio of the fabricated holes on the laser power and number of pulses are revealed experimentally. Microgrooves with good uniformity are fabricated on nickel template with femtosecond laser by optimizing the process parameters.

Abstract: The paper presents a novel method for the separation/enrichment of trace Ni²⁺ using (NH₄)₂SO₄-dithizone(H₂Dz)-cetyl trimethyl ammonium bromide(CTMAB) system.The effects of different parameters on the enrichment yield of Ni²⁺ have been investigated. The possible enrichment mechanism of Ni²⁺ was discussed.The results showed that under the optimum conditions,the water-insoluble chelate of Ni(H₂Dz)₂ which formed by Ni²⁺ and H₂Dz was quantificationally floated onto CTMAB foam phase.In this condition, Cd²⁺、Zn²⁺、Mn²⁺、Fe²⁺ and Co²⁺ could not be floated.Therefore, Ni²⁺ was separated completely from the above metal ions. The proposed method has been successfully applied to the separation/enrichment of Ni²⁺ in various water samples, and the recoveries were 94.2%～103.8%.

Abstract: A bionanocomposite was cast using Ni, TiO₂ and ZnO nanoparticles stabilized by soluble starch (nanoNi, nanoTiO₂ and nanoZnO) as filler in a glycerol plasticized-pea starch (GPS) matrix. Fourier-transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM) results show that nanoparitlces were about 20 nm. In GPS/nanoparticles nanocomposites, loading a low level of nanoparticles improved the mechanical properties. When the nanoparticle content varied from 0 to 4 wt%, the tensile yield strength containing nanoNi, nanoTiO₂ and nanoZnO from 2.08 to 4.05, 8.23 and 11.31 MPa; Young’s modulus increased, from 22.3 to 89.1, 212.6 and 243.5 MPa respectively. The improvement in these properties may be attributed to the interaction between the nanoparticle filler and GPS matrix.

Abstract: ArcGIS analysis was applied to study the concentrations and spatial distribution characteristics of Cr and Ni in surface soil (0~20cm) of corn belt in Dehui—the typical area of black soil in Jilin province. The average concentrations of Cr and Ni were 49.85 mg·kg^-1 and 20.85 mg·kg^-1, which were both lower than the corresponding background value and thus in no pollution level. The trends for soil Cr and Ni were similar with higher concentrations trending N-S across the centre of the study area, while the other hotspots were located in the southwest of Dehui. There was prominent correlation between Cr and Ni in 0.01 level, indicating the close relationship of them. The method based on the geostatistical analysis in ArcGIS can exactly reflect the character of spatial distribution of heavy metals.

Abstract: A nickel nanowire catalyst was prepared by a hard templating method, and characterized by transmission electron microscopy (TEM), N₂ physical adsorption, X-ray photoelectron spectrometry (XPS), X-ray diffraction (XRD) and H₂ temperature-programmed reduction (H₂-TPR). The catalytic properties of the nanowire catalyst in the ethanol steam reforming were compared with a metallic Ni catalyst which was prepared with nickel sponge. The characterization results showed that the nickel nanowire catalyst had high specific surface area and there was more NiO phase in the nickel nanowire catalyst than in the metallic Ni catalyst. The reaction results showed that the nickel nanowire catalyst had higher ethanol conversion and hydrogen yield than the metallic Ni catalyst.

Abstract: The structural features of multilayered "metal - intermetallic" composite materials based on nickel and aluminum, obtained by SPS method have been investigated in this paper. The effect of sintering temperature on phase composition of the intermetallic layers was studied. The influence of intermetallic layers phase composition on the mechanical properties of the composites was estimated.

Abstract: A method for determination of gold, lead, nickel, cobalt in a range of concentrations from mg/g to ng/g was developed. Method can be applied for determination of corresponding metals in ores, rocks and waste mining industry. Method consists of annealing, treatment with hydrofluoric acid and aqua regia followed by extraction (in the case of gold) di-n-octyl sulphide (DOS). Method was tested by certified reference material (8773-2006 РВ 3-8) and various rock samples Altai-Sayan folded area.

Abstract: In this study, recovery of high grade nickel and cadmium products from the multi metal hazardous waste was carried by pyrometallurgical and hydrometallurgical process. Semi-finished products of nickel carbonate and cadmium carbonate were firstly treated from multi metal hazardous waste. Ni-CdO system could be achieved during carbonization in medium temperature reduction. After acid leaching, Cd²⁺ could be separated from nickel. Then the high grade nickel and CdCO₃ products were obtained by smelting and precipitation respectively. The effects of the reducing agent, time, acidity, temperature were investigated. At the optimum conditions, recovery rate of nickel and cadmium is greater than 98%. This process is simple and don't require high temperature, pressure and special complex equipment.