Nickel In Aqueous Solution Research Articles

Thermochemistry of the dissolution of tetra-4-sulfophthalocyanine nickel in aqueous solutions KОН at 298.15 K

We have obtained a nickel tetra-4-sulfophthalocyanine complex, soluble in water. The standard enthalpies of formation of a compound can be considered as the sum of the additive group contributions of fragments of these molecules. We assessed this value using a method based on group systematics with a Benson-type classification of fragments, taking into account the influence of the primary environment of the atoms. In order to obtain the value of the contribution of Ecompl(N)4-Ni, we used the bomb calorimetry method. The enthalpy of combustion of tetrakis (4-methoxyphenyl) porphine and its complex with nickel tetrakis (4-methoxyphenyl) porphine nickel were experimentally determined. Thermal effects of dissolution of crystalline nickel tetra-4-sulfophthalocyanine in aqueous solutions of various KOH concentrations (from 0.002 to 0.02 mol∙L−1) at 298.15 K were determined by the direct calorimetric method. The measurements were carried out in a calorimeter with an isothermal shell equipped with a reaction vessel with a volume of 60 cm3, electric calibration at T = (293.15–308.15) ± 0.01 K and P = 100.5 ± 0.7 kPa, and automatic temperature registration. The standard enthalpy of formation of dissociation products of the tetra-4-sulfophthalocyanine complex with nickel in an aqueous solution has been calculated.

Thermochemistry of the dissolution of tetra-4-sulfophthalocyanine nickel in aqueous solutions KОН at 298.15 K

We have obtained a nickel tetra-4-sulfophthalocyanine complex, soluble in water. The standard enthalpies of formation of a compound can be considered as the sum of the additive group contributions of fragments of these molecules. We assessed this value using a method based on group systematics with a Benson-type classification of fragments, taking into account the influence of the primary environment of the atoms. In order to obtain the value of the contribution of Ecompl(N)4-Ni, we used the bomb calorimetry method. The enthalpy of combustion of tetrakis (4-methoxyphenyl) porphine and its complex with nickel tetrakis (4-methoxyphenyl) porphine nickel were experimentally determined. Thermal effects of dissolution of crystalline nickel tetra-4-sulfophthalocyanine in aqueous solutions of various KOH concentrations (from 0.002 to 0.02 mol∙L−1) at 298.15 K were determined by the direct calorimetric method. The measurements were carried out in a calorimeter with an isothermal shell equipped with a reaction vessel with a volume of 60 cm3, electric calibration at T = (293.15–308.15) ± 0.01 K and P = 100.5 ± 0.7 kPa, and automatic temperature registration. The standard enthalpy of formation of dissociation products of the tetra-4-sulfophthalocyanine complex with nickel in an aqueous solution has been calculated.

ВЛИЯНИЕ СОСТАВА РАСТВОРИТЕЛЯ НА КИНЕТИКУ ГИДРОГЕНИЗАЦИИ 4-НИТРО-2'-ГИДРОКСИ-5'-МЕТИЛАЗОБЕНЗОЛА НА СКЕЛЕТНОМ НИКЕЛЕ В ВОДНЫХ РАСТВОРАХ 2-ПРОПАНОЛА

The article is devoted to the analysis of the kinetics of hydrogenation of 4-nitro-2'-hydroxy-5'-methylazobenzene on skeletal nickel in aqueous solutions of 2-propanol without additives and with additions of acetic acid and hydroxide. Elucidation of the effect of the solvent composition on the kinetics of transformations of compounds containing several reactive groups is a theoretical and practically significant problem. According to the data obtained, during the hydrogenation of 4-nitro-2'-hydroxy-5'-methylazobenzene on skeletal nickel, the introduction of an acid or base into an aqueous solution of 2-propanol of azeotropic composition leads to a change in the ratio of directions in the parallel-sequential scheme of transformations of the starting compound. With the introduction of acetic acid, the contribution of the direction due to the transformation of the azo group noticeably increases, while the introduction of sodium hydroxide completely suppresses this process and the addition of hydrogen in the first phase of the reaction is carried out exclusively at the nitro group in the starting 4-nitro-2'-hydroxy -5'-methylazobenzene. The change in the contributions of the directions associated with the transformation of the azo or nitro group in 4-nitro-2′-hydroxy-5′-methylazobenzene cannot be caused by a change in the excess adsorption values of the hydrogenated compound. When the adsorption values of 4-nitro-2'-hydroxy-5'-methylazobenzene change within 30%, the rate constants of hydrogenation of the starting compound under the influence of the solvent change more than 8 times. One of the reasons for such a change in the observed rate constants for the hydrogenation of 4-nitro-2'-hydroxy-5'-methylazobenzene may be a change in the ratio of forms of hydrogen adsorbed on the catalyst surface under the influence of a solvent.

ELIMINATION OF NICKEL (II) IN WATER WITH DIFFERENT ACTIVATED CARBONS(DATES NUT, PEACH NUTS AND APRICOT KERNELS)

Adsorption Phenomenon the growing demand for adsorbents used in environmental protection processes has made their price more and more expensive, which sparks additional research for the manufacture of new, less expensive adsorbent materials from materials that do not are not classic, Concretely from vegetable waste.This study focuses on the removal of nickel in aqueous solution by different carbon prepared with natural citric acid (0.1N) activated carbon was prepared at carbonization temperatures of 600 ° C.Factors, contact time, mass of coal and initial nickel concentration, have a significant influence on the rate of removal of this metal. The adsorption isotherm for Ni (II) was studied over the concentration range considered where the experimental data are well represented by the Freundlich model. The kinetics is pseudo second order for the adsorption of nickel (II) by activated carbons (date nuts, peach nuts and apricot nuts).

Hydrogenation of Substituted Benzenes Containing Nitro and Azo Groups over Skeletal Nickel in Aqueous Solutions of 2-Propanol

An analysis is made of the kinetic characteristics of the hydrogenation of 4-nitro- and 2-nitro-2'-hydroxy-5'-methylazobenzenes, 4-nitroaniline and 4-aminoazobenzene over skeletal nickel in neutral azeotropic 2-propanol–water mixture and in the same solvent in the presence of acetic acid or sodium hydroxide. It is found that the selectivity of the hydrogenation of these isomers to the intermediate products depends on the composition and nature of the solvent, and is determined by the rate of reactive group conversion. Compared to the process in the presence of sodium hydroxide, which suppresses the route leading to the predominant hydrogenation of the nitro group, the contribution from the transformation of azo group is considerably greater in the hydrogenation of 4-nitro-2'-hydroxy-5'-methylazobenzene in the presence of acetic acid. Adding a base to the solvent during the hydrogenation of 2-nitro-2'-hydroxy-5'-methylazobenzene accelerates the rate of nitro group conversion and the intramolecular cyclization of the intermediate compound, increasing the selectivity towards the products containing the benzotriazole cycle (particularly 2-(2-hydroxy-5-methylphenyl)benzotriazole-N-oxide). The almost linear correlation between the selectivity of the catalytic hydrogenation of isomers of nitro-2'-hydroxy-5'-methylazobenzene and the kinetic characteristics of the hydrogenation of nitro and azo groups in compounds containing a single reactive substituent at different values of medium’s pH is estimated.

Biomineralization based remediation of cadmium and nickel contaminated wastewater by ureolytic bacteria isolated from barn horses soil

Abstract Environmental contamination by toxic heavy metals such as cadmium and nickel is a serious problem. Metal carbonate precipitation has been suggested based on urea decomposition for use in wastewater and soil remediation applications. Therefore, Cd(II) and Ni(II) removal was examined from an environmental viewpoint. In this work, biomineralization of cadmium and nickel in aqueous solutions by six urease-producing bacterial strains isolated from barn horse’s soil samples has been investigated based on microbially induced precipitation (MIP). The enzyme urease produced by these bacteria can hydrolyze urea to carbonate ions leads to increase pH of the wastewater which results in mineralization of the heavy metal ions and their final conversion to metal carbonates precipitates. Only two bacterial strains have been adopted depending on their ability to tolerate high concentrations of toxic metal ions. Bioprecipitation of Cd(II) and Ni(II) was assessed by consideration some factors that affecting on metal bioprecipitation process. These factors include metal toxicity to the bacteria (in term of initial metal concentration) and treatment time. The bioprecipitates were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The selected bacterial isolates demonstrated high endurance with toxic heavy metals and therefore, high Cd(II) and Ni(II) removal rates, ranging from 96% for cadmium to 89% for nickel following incubation for 48 h and at 500 mg/L initial concentration of each Cd(II) and Ni(II). Furthermore, coprecipitation of Cd(II) and Ni(II) with calcite precipitation has been also performed and the results demonstrated that this technique can be beneficial for Cd(II) and Ni(II) biosequestration.

KINETIC OF HYDROGENATION OF 4-NITRO-2'-HYDROXY-5'-METHYLAZOBENZEN ON SKELETAL NICKEL IN AQUEOUS SOLUTION OF 2-PROPANOL

The article is devoted to the kinetics of hydrogenation of 4-nitro-2'-hydroxy-5'-methylazobenzene on skeletal nickel in an aqueous solution of 2-propanol with the azeotropic composition at various initial concentrations of the starting compound. According to the obtained dependences of hydrogen absorption during the process, the changes in the amounts of the initial 4-nitro-2'-hydroxy-5'-methylazobenzene, the processing of the kinetic curves in linear coordinates of different orders, the data on the material balance of reaction products, the conlusion is drawn that at low concentrations the hydrogen addition is carried out through the nitro and azo groups to the starting 4-nitro-2'-hydroxy-5'-methylazobenzene molecule. An increase in the initial amount of 4-nitro-2'-hydroxy-5'-methylazobenzene introduced into the reactor leads to a marked decrease in the content of 4-amino-2'-hydroxy-5'-methylazobenzene. It was experimentally established that at the low initial concentrations, hydrogenation of 4-nitro-2'-hydroxy-5'-methylazobenzene on skeletal nickel in aqueous solution of 2-propanol with the azeotropic composition proceeds on the first order and zero one for hydrogen. An increase in the initial concentration of hydrogenated compound above the solubility limit leads to a sharp increase in a value of excessive adsorption of 4-nitro-2'-hydroxy-5'-methylazobenzene, to an increase in diffusion inhibition on hydrogen and to a change in the order for reducing agent. At the initial amounts of 4-nitro-2'-hydroxy-5'-methylazobenzene studied the transformation proceeds in two parallel directions. One of the directions is due to the addition of hydrogen on nitro groups to form 4-amino-2'-hydroxy-5'-methylazobenzene, and the second one on azo groups to form 2-amino-4-cresol and 4-nitroaniline.Forcitation:Hoang Anh, Kalashnikova V.A., Lefedova O.V. Kinetic of hydrogenation of 4-nitro-2'-hydroxy-5'-methylazobenzen on skeletal nickel in aqueous solution of 2-propanol. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 10-15

Equilibrium and kinetic studies of uptake of nickel in aqueous solution

Equilibrium and kinetic studies of uptake of nickel in aqueous solution

Kinetic description of the hydrogenation of nitrobenzene and nitrosobenzene on skeletal nickel in aqueous solutions of propan-2-ol of different compositions

The kinetics of the hydrogenation of nitrosobenzene and nitrobenzene is simulated taking into account accompanying processes and specific features of the conversion of reactive groups. The constants of the hypothetical reaction steps are calculated. The influence of sodium hydroxide and acetic acid on the kinetic parameters of the reactions is discussed.

Equilibrium and kinetic studies of uptake of nickel in aqueous solution

Equilibrium and kinetic studies of uptake of nickel in aqueous solution

Laser-induced breakdown spectroscopy technique for quantitative analysis of aqueous solution using matrix conversion based on plant fiber spunlaced nonwovens.

In the present work, laser-induced breakdown spectroscopy (LIBS) was applied to detect concentrations of chromium and nickel in aqueous solution in the form of matrix conversion using plant fiber spunlaced nonwovens as a solid-phase support, which can effectively avoid the inherent difficulties such as splashing, a quenching effect, and a shorter plasma lifetime during the liquid LIBS analysis. Drops of the sample solution were transferred to the plant fiber spunlaced nonwovens surface and uniformly diffused from the center to the whole area of the substrate. Owing to good hydrophilicity, the plant fiber spunlaced nonwovens can hold more of the liquid sample, and the surface of this material never wrinkles after being dried in a drying oven, which can effectively reduce the deviation during the LIBS analysis. In addition, the plant fiber spunlaced nonwovens used in the present work are relatively convenient and low cost. Also, the procedure of analysis was simple and fast, which are the unique features of LIBS technology. Therefore, this method has potential applications for practical and in situ analyses. To achieve sensitive elemental detection, the optimal delay time in this experiment was investigated. Under the optimized condition, the limits of detection for Cr and Ni are 0.7 and 5.7 μg·mL(-1), respectively. The results obtained in the present study show that the matrix conversion method is a feasible option for analyzing heavy metals in aqueous solutions by LIBS technology.

Kinetic and computational evaluation of activated carbon produced from rubber tires toward the adsorption of nickel in aqueous solutions

This work aims to evaluate the potential of waste rubber tire as an inexpensive sorbent material for nickel ion removal from aqueous solution. A laboratory scale study carried out on the production of activated carbon (AC) from waste rubber tire by physical activation method. Scanning electron microscope analysis was used to characterize the surface properties of the AC adsorbent. The surface area of AC was measured to be 465 m2/g. This large surface area of the AC could play a vital role in enhancing the removal of Ni(II). Aqueous solutions containing nickel ion in varying concentrations were prepared. Batch adsorption experiments at different operating parameters such as pH, metal concentration, adsorbent dose, contact time and temperature were carried out. These in turn revealed the adsorption capacity and helped in determining the mechanism with respect to thermodynamics, equilibrium and kinetics. The kinetic studies were carried out to determine the kinetics of the adsorption process. The Langmuir isotherm was followed under the present conditions with R2 = 0.938. The overall absolute deviations between experimental and predicted values were found to be 14.4%. The Langmuir model better appears to fit the adsorption of Ni onto AC adsorbent. The characterization and computational studies of the AC adsorbent after adsorption of nickel was also carried out and the results confirmed the positive adsorption process. FTIR analysis of AC before and after Ni adsorption indicated that adsorption of nickel metal on AC took place with the disappearance/diminishing of carbonyl groups. The results of nickel adsorption on AC revealed its potential for pollutant removal and finally its application in water treatment.

A novel process for gasoline desulfurization based on extraction with ionic liquids and reduction by sodium borohydride

A novel integrated process of extraction with ionic liquid (IL) and reductive desulfurization by sodium borohydride (NaBH4) was presented for gasoline desulfurization. The factors that influenced desulfurization efficiency were investigated and desulfurization efficiency reached more than 97% for model gasoline and more than 93% for real gasoline. The components of model gasoline after desulfurization were analyzed by gas chromatography/mass spectrometry (GC/MS) and the reaction routes of model sulfur compounds were proposed. The contents of sulfur, boron and nickel in aqueous solutions were analyzed by Chinese standard method or inductively coupled plasma (ICP). Furthermore, the structures of original and recycled ILs were analyzed by nuclear magnetic resonance (NMR) and the desulfurization performance of recycled ILs was investigated. Results indicated that ILs maintained their original structures after regeneration. Finally, desulfurization kinetics was also probed and results showed that desulfurization reactions of both model sulfur compounds and real gasoline could be treated as pseudo-first-order reactions.

Adsorption of Nickel in Aqueous Solution onto Natural Maghnite

Maghnite clay obtained from Tlemcen, Algeria was investigated to remove heavy metal ion from wastewater. Thus, the present study includes the adsorption of Ni(II) in aqueous solution on maghnite clay through the process of adsorption under various conditions (with variable concentration of metal ion, temperature, pH and mixing time). Increasing pH favours the removal of metal ions till they are precipitated as the insoluble hydroxides. The uptake is rapid with maximum adsorption being observed within 10 min for Ni(II). In addition, the results obtained from adsorption isotherm indicated that these data can be better fitted with the Langmuir and Freundlich equations than the Dubinin-Radushke- vich (D-R) equation.

Phosphine functionalised multiwalled carbon nanotubes: A new adsorbent for the removal of nickel from aqueous solution

Synthesised triphenylphosphine-linked multiwalled carbon nanotubes (Tpp-MWCNTs) were used to study the adsorption of nickel in aqueous solutions and their adsorption capabilities were compared with purified MWCNTs. The adsorption capacity increased with an increase in pH for all adsorbents. The adsorption equilibrium was reached in 40 and 30 min for purified MWCNTs and Tpp-MWCNTs, respectively. Both Freundlich and Langmuir isotherms used to investigate the adsorption process fitted the experimental data well with the correlation coefficient R2 close to 1 for all adsorbents. On the other hand, the experimental data fitted well with a pseudo second-order model. The speciation of nickel also influenced the adsorption on the purified and Tpp-MWCNTs. The adsorbents used in this study showed superior adsorption capacity when compared to other adsorbents reported in the literature.

Surface modification of Cameroonian magnetite rich clay with Eriochrome Black T. Application for adsorption of nickel in aqueous solution

In this study, the surface of Cameroonian magnetite rich clay was modified using Eriochrome Black T, EBT by the batch adsorption method. The EBT-modified magnetite rich clays were used for nickel ions adsorption from aqueous solution. The effect of various experimental factors; the pH of solution, the influence of concentration, the temperature, the contact time and the particle size of the sample were studied by using the batch technique. Adsorption process was better described by the pseudo-second-order kinetic and Tempkin isotherm model. The results showed that the EBT adsorption onto samples is affected by the pH of solution and the maximum EBT ion adsorption takes place between pH 2 and pH 3. The characterization of the surface modification was performed with FTIR and ZPC measurements. The FTIR shows that chemisorption took place at the surface of the bulk samples. The EBT-modified magnetite rich clay presented a binding capacity of nickel ions about 30% higher compared to the unmodified samples from an initial nickel ions concentration of 5.26mmol using 0.5g of sample.

Adsorptive stripping voltammetry of nickel with 1-nitroso-2-napthol using a bismuth film electrode

A sensitive procedure is presented for the voltammetric determination of nickel. The procedure involves an adsorptive accumulation of nickel 1-nitroso-2-napthol (NN) complex on a bismuth film electrode prepared ex situ by electrodeposition. The most suitable operating conditions and parameters such as pH, ligand concentration (CNN), adsorptive potential (Eads), adsorptive time (tads), scan rate and others were selected and the determination of nickel in aqueous solutions using the standard addition method was possible. The adsorbed Ni–NN complex gives a well defined cathodic stripping peak current at −0.70V, which was used for the determination of nickel in the concentration range of 10.0–70.0μgL−1 (pH 7.5; CNN 6.5μmolL−1; Eads −0.30V; tads 60s) with a detection limit of 0.1μgL−1. The relative standard deviation for a solution containing 10.0μgL−1 of Ni(II) was 3.5% (n=4). The proposed method was validated determining Ni(II) in certified reference waste water (SPS-WW1) and Certified Reference Water for Trace Elements (TMDA 51.3) with satisfactory results. Then lake water samples were analyzed.

The kinetics of liquid-phase hydrogenation of sodium maleate by hydrogen adsorbed on the surface of Raney nickel

The kinetics of liquid-phase hydrogenation of sodium maleate by hydrogen adsorbed on the surface of Raney nickel in aqueous solutions was studied by the adsorption-calorimetric method. The kinetic reaction parameters in the surface layer were determined over a broad range of surface coverages. It was proved that a kinetic description in terms of classic kinetic approaches was formal and did not reveal the essence of the process. A description of kinetic reactions in terms of the Elovich equation for uniformly inho-mogeneous surfaces was better grounded physically.

Biosorption of Zinc on Immobilized Green Algae: Equilibrium and Dynamics Studies

The efficacy of using blank alginate beads and immobilized dead algal cells for the removal of zinc ions from aqueous solutions was investigated. It was found that the sorption capacities were significantly affected by solution pH; with higher pH favoring higher zinc ion uptake. Dynamics and isotherm experiments were carried out at the optimal pH 5.0. Zinc uptake on either sorbent was found to be rapid where approximately 90% of the maximum zinc uptake occurred within the first 30 min in both cases of blank alginate and immobilized algal cells. The equilibrium data for the biosorption of zinc ions onto both sorbents were fitted to the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm equations. The presence of copper and nickel in aqueous solutions was found to suppress the sorption process. The results of the dynamics studies revealed that the biosorption of zinc on immobilized dead algal cells followed pseudo-second order kinetics with little intraparticle diffusion mechanism contribution.

The thermodynamic characteristics of processes in Raney nickel surface layers with the participation of adsorbed hydrogen forms

Equilibria between adsorbed hydrogen forms on the surface of Raney nickel in aqueous solutions were studied by the potentiometric and adsorption-calorimetric methods. The establishment of equilibria between adsorbate forms was proved experimentally. The model of a surface with discrete inhomogeneity was used to determine the standard thermodynamic characteristics of surface equilibria and adsorption of particular hydrogen adsorption forms. The influence of pH of the bulk phase on the thermodynamic characteristics of adsorption of hydrogen on the surface of Raney nickel caused redistribution of adsorbed hydrogen forms.