The aim of the research conducted in a 2-year pot experiment in an unheated plastic tunnel was to determine suitability of Miscanthus × giganteus for phytoextraction of nickel from soil as well as to assess tolerance of this species on increasing concentrations of this metal in soil. Pots were filled with mineral soil (sand) and a mixture of soil with high-moor peat and three levels of nickel were introduced, i.e. 75 mg dm-3, 150 mg dm-3 and 600 mg dm-3 and the control combinations used substrates without the addition of nickel. Nickel was introduced only in the first year of the experiment in the form of nickel sulfate (NiSO4 · 6H2O). Miscanthus × giganteus accumulated a considerable amount of nickel in biomass. Miscanthus × giganteus growing in contaminated mineral soil turned out to be a species tolerant to high nickel concentrations

Due to the increasing problem resulting from environmental pollution with heavy metals, great emphasis is placed on the development of removal methods of these pollutants from the environment. This study presents a literature review on the methods for the removal of nickel ions from aqueous solutions such as sorption, especially using low-cost sorbents which are very popular in 21���� century, electrochemical processes and membrane techniques. It is often impossible to use a single technique for efficient removal of heavy metals from wastewater as the process depends on many factors, such as wastewater composition, pH, temperature and many others. The aim of this review is to present some selected removal techniques of nickel(II) from wastewater from the point of view of their efficiency and applicability.

This paper presents the results of research of Ni/diamond composite coatings produced by electrochemical reduction method. Research was focused on composite coatings with nickel matrix and diamond as a disperse phase and for comparison purposes on nanocrystalline nickel coatings. Ni/diamond composite coatings were produced in baths with different content of nanodiamond powder. The structures of the dispersed phase and the composite coatings were analysed by using X-ray diffraction, scanning electron microscopy and light microscopy. Measurements of selected properties of the coatings were performed, including roughness, microhardness, adhesion and abrasive wear resistance. The research results indicate that the produced coatings have a compact structure and good adherence to steel substrate. Moreover, nanocrystalline Ni/diamond composite coatings exhibit greater hardness and reduced abrasive wear resistance compared to nanocrystalline nickel coatings.

Serpentine soils from 16 sample points in Serbia as well as the roots and shoots of eight Brassicaceae family species: Aethionema saxatile, Alyssum montanum, Alyssum repens, Cardamine plumieri, Erysimum linariifolium, Erysimum carniolicum, Isatis tinctoria, Rorippa lippizensis, were analyzed with regard to their concentrations of P, K, Fe, Ca, Mg, Ni, Zn, Mn, Cu, Cr, Cd, and Pb. Most of the soil samples were typical of ultramafic sites with low concentrations of P, K and Ca and high concentrations of Mg, Fe, Ni and Zn. Ca/Mg ratio was <1 in most soil samples and Brassicaceae plants. Only in A. montanum, A. repens, E. linariifolium and R. lippizensis was the Ca/Mg ratio >1. The levels of P, K, Fe and Zn were high, Mn and Cu occurred in low amounts, whereas Cr, Cd, Co and Pb were only traceable. In the roots and shoots of A. montanum and A. repens the measured concentrations of Ni were 657 mg kg-1 and 676 mg kg-1 respectively, which is the first instance that such high concentrations of Ni were detected in these two species.

Zinc plant residue is a hazardous waste which contains high quantity of nickel and other valuable metals. Process parameters such as reaction time, acid concentration, solid-liquid ratio, particle size, stirring speed and temperature for nickel extraction from this waste were optimized using factorial design. Main effects and their interactions were obtained by the analysis of variance ANOVA. Empirical regression model was obtained and used to predict nickel extraction with satisfactory results and to describe the relationship between the predicted results and the experiment results. The important parameters for maximizing nickel extraction were identifi ed to be a leaching time solid-liquid ratio and acid concentration. It was found that above 90% of nickel could be extracted in optimum conditions.

Impact of surface and volume modification and double filtration during pouring the moulds on basic mechanical properties and creep resistance of nickel superalloys IN-713C and MAR-247 in conditions of accelerated creep of castings made of post-production scrap of these alloys is evaluated in this paper. The conditions of initiation and propagation of cracks in the specimens were analysed with consideration of stereological properties of material macro- and microstructure. It has been proven that in the conditions of hightemperature creep at 980°C and at stress σ = 150 MPa, creep resistance of superalloy MAR-247 is more than 10 times higher than the creep resistance of IN-713C alloy. In case of IN-713C alloy, the creep resistance negligibly depends on macrograin sizes. But, the macrograin size considerably affects the time to failure of specimens made of alloy MAR-247. Creep resistance of specimens made of coarse grain material was 20% higher than the resistance of fine grain materials.

The paper presents the adaptation of the modified pulse method for investigating temperature characteristics of thermal diffusivity in the vicinity of the second-order phase transition points. The principle of the adaptation consists in the modified in relation to the original method, development of the characteristics of temperature changes between boundary surfaces of a flat-parallel specimen after the laser shot onto its front surface. The application of this adaptation was illustrated with investigation into thermal diffusivity of nickel (99.9% wt) in the temperature range of 20-380◦C. In all cases the measurement error was less than 3%, and the averaging interval for the measured values of thermal diffusivity was not greater than 1.2 K.

FeCl3 bearing etching solution is mainly used for etching of metals used in shadow masks, PCBs and so on. Due course of Invar alloy etching process the FeCl3 bearing etching solution get contaminated with Ni2+ which affect adversely the etching efficiency. Hence, FeCl3 bearing etching solution discarded after several cycle of operation causes an environmental and economic problem. To address both the issues the etching solution was purified through solvent extraction and remained Ni2+ recovered by wet chemical reduction using hydrazine. For optimum Fe3+ extraction efficiency, various extraction parameter were optimized and size and morphology of the recovered pure Ni powder was analyzed. The reported process is a simple process to purify and recover Ni from industry etching solution.

Nickel damages the male reproductive system. We investigated the beneficial effects of silibinin which has metal-chelating and antioxidant properties over nickel toxicity. Both antioxidative effects in testes and overall effects related to sperm motility, membrane and acrosome integrity of orally administered Silibinin were evaluated against the harmful effects of 30 day of intraperitoneal nickel sulfate (5 mg/kg/day) administration in rats. Male rats were randomized into control (Group1; n=6) and three experimental groups (n=6, each): Group2 Nickel sulfate (5 mg/kg/day), Group3 Silibinin (150 mg/kg/day), and Group 4 Nickel sulfate (5 mg/kg/day) + Silibinin (150 mg/kg/day). We found higher sperm motility, viable sperm and total sperm count in Groups 3 and 4 than the Group 2 treatment groups and the percentage of abnormal spermatozoa was similar in both groups (Groups 2 and 4). Increased apoptosis, activation of caspase3, 8, 9 and TUNEL were detected in Group 2. However, activation of caspase3, 8, 9 and TUNEL was reduced in Group 4. The protective effects of silibinin were demonstrated on histopathologic findings and some sperm parameters (sperm motility percentage, viable spermatozoa, sperm count, and abnormal spermatozoa percentage) in rats exposed to nickel.

In the domain of the equipment and apparatus construction, a permanent preoccupation worldwide is ensuring technical performances and high fiability in exploitation. The users’ requirement growth in this field led to producing materials with high characteristics such as iron-nickel alloys having a high nickel content with special magnetic, thermal, or elastic properties. The theoretical and experimental researches had the aim of obtaining cold rolled strip, thin (2.6 mm) and narrow (86 mm) from iron-nickel alloys with 41% Ni (low content of C: 0.02-0.04%; Fe: 58%; other elements: Mn, Si, Cu, Cr, Al: under 1%). Our own experiments aimed to establish an optimal cold rolling technology of hot rolled strips of iron-nickel alloys, in order to obtain cold rolled strips with superior mechanical and technological characteristics, strip profile according to current standards, including a finished product characterization.

This work presents the results of a study whose aim was to determine the influence of algal blooms on precipitation of heavy metals. The scope of the study covered culture of a mixed population made up of Scenedesmus and Pseudokirchneriella algae in experimental conditions and initiating a metal biosorption process with the use of culture biomass by administering ions of Zn(II) and Ni(II). The process was controlled by assessing the level of biosorption of metals entered at a one-off basis in the form of Zn(II) and Ni(II) salts or in the form of mixture of both ions, in comparison to the control sample, at different exposure times (2 hours and 24 hours). The presence of metals was determined both in the biomass and in the culture medium. The presented results of the study confirm the effectiveness of Chlorophyta in the process of zinc and nickel biosorption. A phenomenon of competitiveness between the metals was observed when they were administered at the same time.

Paper presents the results of evaluation of heat resistance and specific heat capacity of MAR-M-200, MAR-M-247 and Rene 80 nickel

superalloys. Heat resistance was evaluated using cyclic method. Every cycle included heating in 1100°C for 23 hours and cooling for 1

hour in air. Microstructure of the scale was observed using electron microscope. Specific heat capacity was measured using DSC

calorimeter. It was found that under conditions of cyclically changing temperature alloy MAR-M-247 exhibits highest heat resistance.

Formed oxide scale is heterophasic mixture of alloying elements, under which an internal oxidation zone was present. MAR-M-200 alloy

has higher specific heat capacity compared to MAR-M-247. For tested alloys in the temperature range from 550°C to 800°C precipitation

processes (γ′, γ′′) are probably occurring, resulting in a sudden increase in the observed heat capacity.

Superalloys show a good combination of mechanical strength and resistance to surface degradation under the influence of chemically

active environments at high temperature. They are characterized by very high heat and creep resistance. Their main application is in gas

turbines, chemical industry, and in all those cases where resistance to creep and the aggressive corrosion environment is required. Modern

jet engines could never come into use if not for progress in the development of superalloys. Superalloys are based on iron, nickel and

cobalt. The most common and the most interesting group includes superalloys based on nickel. They carry loads at temperatures well in

excess of the eighty percent of the melting point. This group includes the H282 alloy, whose nominal chemical composition is as follows

(wt%): Ni - base, Fe - max. 1.5%, Al - 1.5% Ti - 2.1%, C - 0.06% Co - 10% Cr - 20% Mo - 8.5%. This study shows the results of thermal

analysis of the H282 alloy performed on a cast step block with different wall thickness. Using the results of measurements, changes in the

temperature of H282 alloy during its solidification were determined, and the relationship dT / dt = f (t) was derived. The results of the

measurements taken at different points in the cast step block allowed identifying a number of thermal characteristics of the investigated

alloy and linking the size of the dendrites formed in a metal matrix (DAS) with the thermal effect of solidification. It was found that the

time of solidification prolonged from less than ome minute at 10 mm wall thickness to over seven minutes at the wall thickness of 44 mm

doubled the value of DAS.

Nickel alloys belong to the group of most resistant materials when used under the extreme operating conditions, including chemically

aggressive environment, high temperature, and high loads applied over a long period of time. Although in the global technology market

one can find several standard cast nickel alloys, the vast majority of components operating in machines and equipment are made from

alloys processed by the costly metalworking operations. Analysis of the available literature and own studies have shown that the use of

casting technology in the manufacture of components from nickel alloys poses a lot of difficulty. This is due to the adverse technological

properties of these alloys, like poor fluidity, high casting shrinkage, and above all, high reactivity of liquid metal with the atmospheric air

over the bath and with the ceramic material of both the crucible and foundry mold. The scale of these problems increases with the expected

growth of performance properties which these alloys should offer to the user.

This article presents the results of studies of physico-chemical interactions that occur between theH282alloy melt and selected refractory

ceramic materials commonly used in foundry. Own methodology for conducting micro-melts on a laboratory scale was elaborated and

discussed. The results obtained have revealed that the alumina-based ceramics exhibits greater reactivity in contact with the H282 alloy

melt than the materials based on zirconium compounds. In the conducted experiments, the ceramic materials based on zirconium silicate

have proved to be a much better choice than the zirconia-silica mixture. Regardless of the type of the ceramic materials used, the time and

temperature of their contact with the nickel alloy melt should always be limited to an absolutely necessary minimum required by the

technological regime.

Inconel 713C is a nickel-based casting alloy characterised by improved heat and creep resistance [1]. It is used e.g. in aircraft engine components, mainly in the form of precision castings. Precision casting enables very good reproduction of complex shapes. However, due to major differences in casting wall thickness and the resultant differences in rigidity, defects can form in precision castings. The most common defects in precision castings are shrinkage porosities and microcracks. Inconel 713C is considered to be a difficult-to-weld or even non-weldable alloy. However, the need to repair precision castings requires attempts to develop technologies for their remelting and pad welding which could be used in industrial practice. This article presents the results of tests consisting in TIG pad welding of defects identified in precision castings intended for the aircraft industry. It was found that the main reason behind failed attempts at repairing precision castings by welding technologies was hot cracking in the fusion zone. Such cracks form as a result of the partial melting of intercrystalline regions along the fusion line. The deformations occurring during the crystallization of the melting-affected zone (fusion zone + partially melted zone + heat affected zone) or pad weld lead to the rupture of the intercrystalline liquid film. Hot cracks form within the so-called high-temperature brittleness range (HTBR) of the alloy. Another type of cracks that was identified were ductility dip cracks (DDC), whose formation is related to the partial melting of carbides.

The article deals with the influence of chemical composition of martensitic stainless steel for castings GXCrNi13-4 (the 1.4317 material) on mechanical properties and structure of as cast steel after heat treatment. Properties of these martensitic stainless steel are heavily influenced by chemical composition and structure of the material after heat treatment. Structure of these steels after quenching is formed with martensite and residual austenite. When tempering the steel the carbon content in martensite is reduced and gently deposited carbides occur. The way of heat treatment has a major impact on structure of martensitic steels with low carbon content and thus on strength, hardness and elongation to fracture of these steels. Chemical composition of the melt has been treated to the desired composition of the lower, middle and upper bounds of the nickel content in the steel within the limits allowed by the standard. Test blocks were gradually cast from the melt. The influence of the nickel equivalent value on structure and properties of the 1.4317 steel was determined from results of mechanical tests.

The paper presents the results of studies to determine the effect of complex surface and bulk modification and double filtration during mould pouring on the stereological parameters of macrostructure and mechanical properties of castings made from the post-production waste IN-713C and the MAR-247 nickel alloys. The evaluation covered the number of grains per 1mm2 of the sample surface area, the average area of grains and the shape index, hardness HB, tensile strength and resistance to high temperature creep. The results indicate the possibility of controlling the stereological parameters of macrostructure through application of several variants of the modification, controlling in this way also different low- and high-temperature properties. The positive effect of double filtration of the alloy during mould pouring on the metallurgical quality and mechanical properties of castings has also been emphasized.

Determined was quantitative effect of nickel equivalent value on austenite decomposition degree during cooling-down castings of Ni-MnCu cast iron. Chemical composition of the alloy was 1.8 to 5.0 % C, 1.3 to 3.0 % Si, 3.1 to 7.7 % Ni, 0.4 to 6.3 % Mn, 0.1 to 4.9 % Cu, 0.14 to 0.16 % P and 0.03 to 0.04 % S. Analysed were castings with representative wall thickness 10, 15 and 20 mm. Scope of the examination comprised chemical analysis (including WDS), microscopic observations (optical and scanning microscopy, image analyser), as well as Brinell hardness and HV microhardness measurements of structural components.

The paper presents results of research on cobalt and nickel ions removal from monocomponent solutions

using Purolite ion exchange resins. It has been shown that C 160 ion exchange resin has the best

sorption properties for both ions (Qe – 72.5 mg Co/g and 88.2 mg Ni/g). Regeneration process of this

ion exchanger has high efficiency, achieving about 93% for cobalt ions and about 84% in case of nickel

ions. It has been shown that the use of ion exchange method with suitable ion exchange resins guarantees

effective removal of cobalt and nickel ions from solutions with very high concentrations corresponding

to contents of these metals in industrial wastewaters (e.g. galvanic). In case of C 160 ion exchange resin,

after the sorption process is carried out in one 50 minute cycle, the cobalt concentration decreased from

about 30 000 mg/L to about 9 500 mg/L (approx. 68%), whereas nickel concentration reached about

6 300 mg/L (approx. 79%). Studied chelating resins don’t have such high sorption capacities. In their

case, it is required to convert cobalt and nickel ions into complex forms. The kinetics of studied processes

were described by pseudo-second order equations.

The paper presents the results of studies of hybrid composite layers Ni/Al2O3/Cgraphite produced by the electrodeposition method. Three variants of hybrid composite layers were prepared in electrolyte solutions with the same amounts of each dispersion phases which were equal to 0.25; 0.50 and 0.75 g/dm3. The structure of Ni/Al2O3/Cgraphite layers as well as the Al2O3 and graphite powders, which were used as dispersion phases was investigated. The results of morphology and surface topography of produced layers are presented. The modulus of elasticity and microhardness of the material of produced layers were determined by DSI method. Tribological and corrosion resistance tests of produced layers were carried out. Realized studies have shown that the material of the produced layers is characterized by a nanocrystalline structure. Incorporation of dispersion phases into the nickiel matrix increases the degree of surface development of layers. Ni/Al2O3/Cgraphite layers are characterized by high hardness and abrasion resistance by friction, furthermore, they provide good corrosion protection for the substrate material.

Zanieczyszczenia przemysłowe przyczyniają się z reguły do poglębicnia degradacji rolniczej przestrzeni produkcyjnej, prowadząc między innymi do nagromadzenia metali ciężkich w glebie. Do grupy metali ciężkichzaliczany jest nikiel, który w małych ilościach jest niezbędny dla wzrostu i rozwoju organizmów żywych, natomiast występujący w nadmiarze jest toksyczny. W czteroletnim doświadczeniu wazonowym badano wpływ zanieczyszczenia gleby niklem (50, I 00 i 150 mg Ni/kg gleby zastosowanego w formie NiSO,711,O) na tic zróżnicowanego wapnowania (wg 0,5; I i 1.5 Hh gleby zastosowanego w formie CaCO) na zawartość Pb i Mn w koniczynie czerwonej. Zawartość metali oznaczono metodą ICP-J\ES po wcześniejszej mineralizacji materiału roślinnego ,,na sucho" w piecu muflowym w temperaturze 450°C i rozpuszczeniu popiołu w I 0% roztworze HCL. Wyniki badań opracowano statystycznie analizą wariancji z wykorzystaniem rozkładu F-FisheraSnedecora wg programu F.R. Anal.var 4.1., a wartość NIR.,5 wyliczono wg testu Tukeya. W celu znalezienia związków między badanymi cechami w pracy przeprowadzono również analizę korelacji liniowej. Zawartość obu metali w roślinach uprawianych na glebach zanieczyszczonych niklem była większa w odniesieniu do roślin uprawianych na glebach niezanieczyszczonych, co może świadczyć o synergizmie niklu i omawianych metali. Zastosowane wapniowanie (niezależnie od ilości CaCO, wprowadzonego do gleby) powodowało istotne zmniejszenie zawartości obu metali w roślinie testowej. Przeprowadzone badania wykazały synergistyczne zależności pomiędzy niklem a ołowiem i manganem.

The profile differences of zinc, copper, and nickel contents in forest podzolic soils on South-Podlasie Lowland wen: studied. Their considerable differentiation was found. Contents and differentiation of analyzed heavy metals in studied soil horizons were determined by: parents rock and soil-forming processes (mainly podzolization) characteristic for those soils.