Nickel Ion Concentration Research Articles

니켈 함유 폐수의 침전 처리에 대한 열역학적 기초 연구

Nickel is a widely used chemical species, but it is also known for its toxicity. The Pourbaix diagrams were constructed to investigate the influences of temperature and hydrogen ion on wastewater which contains nickel ion. Nickel exists as Ni₃O₄, Ni(OH)₂, Ni²⁺, and Ni in the water of pH 0 to 14. In the temperature range of 288K to 318K, Ni(OH)₂ was shown to have stable region from pH 5.7 to pH 14, and the area of stable region increases with temperature. The ratio of Ni(OH)₂ to Ni and the ratio of Ni(OH)₂ to Ni²⁺ wereexamined to be greater than the ratios of Ni₃O₄ to Ni and Ni₃O₄ to Ni²⁺, respectively. Also, the ratio of Ni(OH)₂ to Ni²⁺ and the ratio of Ni₃O₄ to Ni²⁺ were shown to be proportional to the temperature, while Ni was not. The reduction-precipitation process of nickel ion to Ni(OH)₂ by controlling the pH depending on the temperature following the value of pH 6.29 at 288K, pH 6.08 at 298K, pH 5.88 at 308K, and pH 5.70 at 318K, can be used to decrease concentration of nickel ion in wastewater and recover nickel from wastewater in the form of Ni(OH)₂.

The influence of nickel(II) ions in soil on total antioxidant activity and components of the ascorbat-glutathione cycle in transgenic plants Nicotiana tabacum

We conducted a comparative analysis of some biochemical parameters in non-transgenic and transgenic plants Nicotiana tabacum, cultivated in soil with an increased concentration of nickel(II) ions. Transgenic plants had in their genome a bacterial acdS-gene encoding the 1-aminocyclopropane-1-carboxylate deaminase (ACC-deaminase) enzyme. The introduction of elevated concentrations of nickel ions into the soil promotes induction of the acdS-gene expression and an increase in ACC-deaminase activity in transgenic plants. It was shown that the total antioxidant activity and the content of ascorbic acid, glutathione, ascorbate peroxidase, glutathione peroxidase and glutathione reductase increased in plants under abiotic stress.

Distinct effects of transition metal (cobalt, manganese and nickel) ion substitutions on the abiotic oxidation of pyrite: In view of hydroxyl radical production

The abiotic oxidation of pyrite (FeS2) is a geochemically crucial reaction involved in acid mine drainage, the release of toxic trace elements and the generation of hydroxyl radicals (•OH) that can oxidize environmental substances. Studies on •OH generation from the abiotic oxidation of pyrite have drawn wide interest, but the effects of the common substitution of transition metal ions on •OH generation are still largely unknown, and worthy of comprehensive comparison. We therefore synthesized and comprehensively characterized micron-sized pyrites containing low concentrations of cobalt (Co), nickel (Ni), or manganese (Mn) ions, and tested the relative ability of these transition metal ion-substituted pyrites to generate •OH under abiotic oxidation. We found that transition metal ion substitutions inhibited the growth of pyrite crystals to various extents and increased Fe–S bond distances, leading to distinct alterations in surface chemical composition, conductivity, and the exposure of active faces. These differences resulted in an increase in •OH generation by the oxidation of transition metal ion-substituted pyrites, relative to pure pyrite, with the order of increase being Mn2+-substituted < Ni2+-substituted < Co2+-substituted pyrites. These substituent-dependent differences were explored by linking the crystal properties and physical chemistry of these pyrites to various reaction pathways that were possible in such contexts. For pure pyrite, the heterogeneous Fenton reaction was the chief generator of •OH. The substitution of pyrite with Co2+, which was redox-active, increased the conductivity of pyrite and accelerated the reduction of surface Fe3+ to Fe2+, resulting in a significant increase in H2O2 and •OH production. The substitution of pyrite with Mn2+, which was also redox-active, likewise increased the conductivity; however, the high oxidizing ability of surface Mn4+ inhibited the reduction of Fe3+ and thus decreased •OH generation. By contrast, the substitution of pyrite with Ni2+ did not affect electron transfer but led to absolute exposure of the (111) face of pyrite, which increased its activity toward O2 and H2O, slightly increasing H2O2 and •OH generation. These results highlight the vital role of transition metal ion-substituted pyrite in various geochemical processes.

Синтез, структурные и магнитные свойства людвигита Mn-=SUB=-1.32-=/SUB=-Ni-=SUB=-0.85-=/SUB=-Cu-=SUB=-0.83-=/SUB=-BO-=SUB=-5-=/SUB=-

Single crystals of Mn1.32Ni0.85Cu0.83BO5 with the ludwigite structure were obtained by the solution-melt method during spontaneous crystallization. The concentration of copper, manganese and nickel ions was determined by transmission microscopy. Manganese ions are included in compounds in the divalent and trivalent states. The study of temperature and field dependences showed that we have several magnetic transitions. The first transition, associated with the ferrimagnetic ordering of the magnetic moments of parts of the ions, observed in the region of 50 K. In the region of 25 K, a second magnetic transition is observed. Substitution of nickel ions for copper and divalent manganese of better disorder and competition of exchange interactions, which leads to the division of the magnetic system into several magnetic subsystems that are ordered at different temperatures.

Synthesis, structural and magnetic properties of ludwigite Mn-=SUB=-1.32-=/SUB=-Ni-=SUB=-0.85-=/SUB=-Cu-=SUB=-0.83-=/SUB=-BO-=SUB=-5-=/SUB=-

Single crystals of Mn1.32Ni0.85Cu0.83BO5 with the ludwigite structure were obtained by the solution-melt method during spontaneous crystallization. The concentration of copper, manganese and nickel ions was determined by transmission microscopy. Manganese ions are included in compounds in the divalent and trivalent states. The study of temperature and field dependences showed that we have several magnetic transitions. The first transition, associated with the ferrimagnetic ordering of the magnetic moments of parts of the ions, observed in the region of 50 K. In the region of 25 K, a second magnetic transition is observed. Substitution of nickel ions for copper and divalent manganese of better disorder and competition of exchange interactions, which leads to the division of the magnetic system into several magnetic subsystems that are ordered at different temperatures. Keywords: ludwigites, magnetic interface transition, indirect exchange interactions.

Surfactant-Free Facile Synthesis of Nickel Oxalate Monodispersed Particles in Novel Morphologies

The surfactant or shape modifier used in the synthesis of monodispersed uniform fine particles affected the performance of the prepared powder in its applications. The present investigation is related to synthesizing colloidal uniform fine particles of nickel oxalate in novel morphologies under an optimized set of reaction conditions without using any surfactant or shape modifier. SEM results revealed that the reactant concentration significantly affected the characteristics of the precipitated solids, which ranged from gel to dispersion of discrete particles. Particles of uniform morphological features were obtained under an optimized set of experimental conditions, i.e., reactant concentration, temperature, aging time, etc. The molar ratio of the precursors affected the particle’s growth mechanism as the spherical morphology of the particles changed to a cubic shape by increasing nickel ion concentration in the recipe at 25 oC. The cubic morphology transformed into toffee shape bigger particles of a 0.5 axial ratio by increasing the reaction mediumand#39;s thermal energy. The synthesized particles were characterized by various physical techniques, which confirmed the product as the monodispersed pure NiC2O4.2H2O particles.

Morphology controllable NiCo2S4 nanostructure on carbon cloth for enhanced electrocatalytic water oxidation

Oxygen evolution reaction (OER) is one of the key factors restricting the whole process of improving the efficiency of water splitting. Here, we report a synthesis strategy that uses a two-step reaction of hydrothermal co-precipitation and sulfuration to directly grow starfish-like spinel NixCo3−xS4 (0 ≤ x ≤ 3) nanorods on carbon cloth through controlling the concentration of Ni. The as-obtained Ni0.58Co2.42S4 possess the anodic overpotential of 215 mV in alkaline media to drive the current density of 10 mA cm−2, better than advanced precious metal catalysts RuO2 and IrO2. Furthermore, compared with other synthesized catalysts with different nickel ion concentrations, Ni0.58Co2.42S4 has a unique starfish morphology and highest value of Co3+/Co2+ and lowest value of Ni3+/Ni2+ sites, which is helpful for the dissipation of gas products on the catalyst surface and exhibits superior OER activity. The optimal configuration of surface valence states of Ni0.58Co2.42S4 sample can optimize the adsorption, activation and desorption of water and oxygen, thus significantly improve the electrocatalytic activity. This work provides a promising way to develop high properties and low-cost non-noble metal water oxidation catalysts.

Removal of Nickel Ions from Aqueous Solutions by 2-Hydroxyethyl Acrylate/Itaconic Acid Hydrogels Optimized with Response Surface Methodology.

The adsorption of Ni2+ ions from water solutions by using hydrogels based on 2-hydroxyethyl acrylate (HEA) and itaconic acid (IA) was studied. Hydrogel synthesis was optimized with response surface methodology (RSM). The hydrogel with the best adsorption capacity towards Ni2+ ions was chosen for further experiments. The hydrogel was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis before and after the adsorption of Ni2+ ions. Batch equilibrium experiments were conducted to investigate the influence of solution pH, hydrogel weight, ionic strength, adsorption time, temperature and initial concentration of nickel ions on the adsorption. Time-dependent adsorption fitted the best to the pseudo-second-order kinetic model. A thermodynamic study revealed that the adsorption was an exothermic and non-spontaneous process. Five isotherm models were studied, and the best fit was obtained with the Redlich–Peterson model. Consecutive adsorption/desorption studies indicated that the HEA/IA hydrogel can be efficiently used as a sorbent for the removal of Ni2+ ions from the water solution. This study develops a potential adsorbent for the effective removal of trace nickel ions.

Electrochemical Ni-EDTA degradation and Ni removal from electroless plating wastewaters using an innovative Ni-doped PbO2 anode: Optimization and mechanism

In this work, a novel Ni-doped PbO2 anode (Ni-PbO2) was prepared via a co-electrodeposition method and used to remove Ni-ethylenediaminetetraacetic acid (Ni-EDTA) from solutions typical of electroless nickel plating wastewater. Compared with a pure PbO2 electrode, Ni doping increased the oxygen evolution potential as well as the reactive surface area and reactive site concentration and reduced the electron transfer resistance thereby resulting in superior Ni-EDTA degradation performance. The 1% Ni-doped PbO2 electrode exhibited the best electrochemical oxidation activity with a Ni-EDTA removal efficiency of 96.5 ± 1.2%, a Ni removal efficiency of 52.1 ± 1.4% and an energy consumption of 2.6 kWh m−3. Further investigations revealed that 1% Ni doping enhanced both direct oxidation and hydroxyl radical mediated oxidation processes involved in Ni-EDTA degradation. A mechanism for Ni-EDTA degradation is proposed based on the identified products. The free nickel ion concentration initially increased as a result of the degradation of Ni-EDTA complexes and subsequently decreased as a consequence of nickel electrodeposition on the cathode surface. Further characterization of the cathode deposits by X-ray diffraction and X-ray photoelectron spectra indicated that the deposition products were a mixture of Ni0, NiO and Ni(OH)2 with elemental Ni accounting for roughly 80% of the deposited nickel. Results of this study pave the way for the application of anodic oxidation processes for efficient degradation of Ni-containing complexes and recovery of Ni from nickel-containing wastewaters.

A Highly Selective and Interference-Resistive Opto-Mechatronic Sensor for Fast Detection of Nickel Ions

In this research, we developed an innovative, miniature, low-cost, and fast-response nickel ion photoelectric sensor system using the principle of light absorption characteristics described by Beer–Lambert’s law. We used the proposed ideas to analyze the absorption spectrum of nickel ions in aqueous solutions and selected a unique UV absorption band for these ions, and successfully fabricated an initial photoelectric sensor system. A quantitative study through the relationship between the concentration of nickel ions in the aqueous solution and the degree of light absorption was conducted. When other metal ions (such as Cd, Pb, Fe and Cl) co-exist, the nickel ion photoelectric sensor shows excellent selectivity and has sufficient linearity and good repeatability. The sensitivity of the originally designed photoelectric sensing system for Ni ions is 1.58 UVA intensity (A.U.)/ppm with excellent ion-selective characteristics and interference-resistant ability in terms of its complexity and fabrication cost.

Preparation of Graphene Oxide-loaded Nickel with Excellent Antibacterial Property by Magnetic Field-Assisted Scanning Jet Electrodeposition.

Graphene oxide (GO) is recognized as a promising antibacterial material that is expected to be used to prepare a new generation of high-efficiency antibacterial coatings. The propensity of GO to agglomeration makes it difficult to apply it effectively. A new method of preparing GO-loaded nickel (GNC) with excellent antibacterial property is proposed in this paper. In this work, GNC was prepared on a titanium sheet by magnetic field-assisted scanning jet electrodeposition. The massive introduction of GO on the coating was proven by energy disperse spectroscopy and Raman spectroscopy. The antibacterial performance of GNC was proven by agar plate assessment and cell living/dead staining. The detection of intracellular reactive oxygen species (ROS) and the concentration of nickel ions, indicate that the antibacterial property of GNC are not entirely derived from the nickel ions released by the coating and the intracellular ROS induced by nickel ions, but rather are due to the synergistic effect of nickel ions and GO.

Removing high concentration of nickel (II) ions from synthetic wastewater by an indigenous microalgae consortium with a Revolving Algal Biofilm (RAB) system

This work is to evaluate the feasibility of using a revolving algal biofilm (RAB) reactor for nickel (Ni) removal from high strength industrial wastewater. The RAB reactor can grow an indigenous microalgal species consortium in a wastewater containing up to 5000 mg/L of Ni. The tolerance of RAB biomass to the high strength nickel was attributed to maintaining cells membrane integrity, which is possible due to its high amount of extracellular polymer substances (EPS). The RAB system also demonstrated a superior Ni removal performance with >90% Ni removal efficiency and 534 mg/L-day Ni removal rate. The advantage of RAB system in nickel removal over suspended-based system might be attributed to the high contents of EPS in RAB biofilm, given the fact that the extracellular nickel occupied 60% or higher of the total nickel in the RAB biofilm. The adsorption of Ni by the biomass harvested from the RAB reactors was also studied. The “biomass-physical-adsorption” was less effective than “growing-algae-while-removing-Ni” for Ni removal. Collectively, the results in this study demonstrated that the RAB reactor is a potential system for Ni removal from high strength industrial wastewater.

A comparative study for the rejection of nickel ions from waste water by PES, fMWCNTs/PES, TiO2/PES and TiO2-fMWCNTs/PES mixed matrix membranes

In this study, the neat polyethersulfone (PES) membrane and the mixed matrix membranes (MMMs) containing 20 wt. %polyethersulfone (PES) and different amounts of functionalized multi-walled carbon nanotubes (fMWCNTs), TiO2, and TiO2 coated on fMWCNTs were fabricated by wet phase inversion and conventional casting methods. The nickel ions rejection and permeate flux performance were then investigated and compared by these fabricated membranes. The characteristics of the membranes were performed by field emission scanning electron microscopy (FESEM), transmissionelectron microscopy (TEM), and contact angle (CA) measurement. The operational parameters such as polymer concentration, pressure, pH, time and nickel ion concentration for nickel ions rejection and permeability were firstly optimized on the neat PES membrane. The performance of MMMs containing various amounts of nanoparticles was then evaluated and compared under these optimized conditions. The obtained results indicated that the membrane containing 20 wt. % PES, and operational conditions like pressure 15bar, low concentration of nickel, time =30min, and various amounts of pH were the best conditions to achieve the highest rejection percentage of nickel ions and permeate flux. In such operational conditions, PES/fMWCNTs and PES/TiO2 membranes have the highest nickel ion rejection and permeate flux, respectively. Totally the prepared mixed matrix membranes showed that they have higher ability to reject nickel ions from wastewater and a higher permeate flux value compared with the neat PES membrane.

Integrated sulfide alkali wastewater treatment using spent galvanic solutions

We identified the efficiency of spent Ni2+-containing galvanic solutions for removing sulfide ions from sulfide alkali wastewater. It was found that the removal of sulfide ions led to achieving 89.7 % of purification degree by the chemical oxygen demand value. We also studied how various concentrations of nickel (II) and copper (II) ions affect the oxidation intensity of pollutants in mixed wastewater with ambient oxygen and with ozone-air mixture. Optimal conditions were identified for cleaning sulfide alkali wastewater from hydrocarbons: Oxidation of organic components by ozone-air mixture for 30 minutes, containing 300 mg/dm3 of nickel (II) ions; implementing such conditions resulted in the greatest reduction of the chemical oxygen demand value (down to 798 mg of O/dm3. A comprehensive method for the purification of sulfur-alkaline wastewater is proposed, which includes the stages of removing readily volatile hydrocarbons by simple distillation, sulfide ions by reagent deposition using spent Ni2+-containing galvanic solutions, and soluble hydrocarbons by oxidation of ozone-air mixture with adding 300 mg/dm3 of nickel (II) ions contained in galvanic wastewater. Implementation of this technique led to achieving 96% of the wastewater purification degree by the chemical oxygen demand value, which allows discharging wastewater into biological treatment.

Removal of low concentrations of nickel ions in electroplating wastewater using capacitive deionization technology

The capacitive deionization (CDI) technology was adopted to reduce the low concentrations of nickel in electroplating wastewater to meet the discharge standard. The composite anode and the composite cathode (Resin-CGA) were prepared by incorporating anion-exchange resin (AR-CGA) and cation exchange resin (CR-CGA) into the titanium mesh by the conductive graphite adhesive, respectively. The electrolytic performances of the Resin-CGA electrodes at different cell voltages, initial electrolyte pH and initial nickel concentrations were investigated. The adsorbed amount of nickel on the CR-CGA electrodes and the removal percentage of nickel were 0.095 mg g−1 and 95%, respectively. The Ni2+ concentrations were reduced to 0.005 mg L−1 and the electricity consumption was 1.6 kWh per ton of the electroplating wastewater at the initial Ni2+ concentrations of 1.0 mg L−1 under the optimal conditions, exhibiting better electrolytic performance than the cation-exchange resin and the electrodes prepared by the conductivity graphite adhesive (CGA). In addition, the spent electrodes were electrochemically regenerated and the electrolytic performance of the Resin-CGA electrodes kept stable during the cycles. This study provided a promising method to reduce the low concentrations of Ni2+ to less than 0.1 mg L−1 in the treatment of electroplating wastewater.

Using Photovoltaic to Remove Heavy Metals from Industrial Water

Heavy metals pollution has become a more serious environmental problem in the last several decades as a result of releasing toxic materials into the environment. The aim of this study is to develop an ecological method for the removal of Ni2+ ions from industrial wastewater by an electro coagulation method using aluminum plates and solar cell as a source of D.C current. In this study, different conditions of pH of 4, 6, 7, and 8, current densities of 0.5, 1.0, and 1.5 mA/cm2, and nickel ion concentrations of 200, 300, and 500 ppm were investigated during a period of time of 120 minutes to remove nickel ions prepared waste water by electro coagulation. The total removal of nickel ions was (97.5- 99.5%), (97- 99%), and (96.67-98.8%) for pH (4-8), current density (0.5-1.5 mA/cm2) and nickel ions concentration (200-500 ppm), respectively. The results show that the optimum condition of electro coagulation process can be obtained at pH = 8 and current density 1.5 mA/cm2 when 120 minutes were elapsed.

Modelling and optimisation of hardness in citrate stabilised electroless nickel boron (ENi-B) coatings using back propagation neural network – Box Behnken design and simulated annealing – genetic algorithm

ABSTRACT In this work, a novel citrate stabilised electroless bath was developed and the process parameters (concentrations of nickel, reducing agent, and stabiliser) were optimised to achieve the maximum hardness in the ENi-B deposit on 7075-T6 aluminium alloy, using the back-propagation neural network (BPNN), Box–Behnken design (BBD), simulated annealing (SA) and genetic algorithm (GA). The effect of independent variables on dependent variable was modelled using the BPNN and BBD. The models were assessed for their significance using the coefficient of determination (R2) and mean squared error (MSE). The MSE and R2 of 34.18 and 0.9852 were obtained for BPNN model against 20.48 and 0.9911 for BBD, which proved that the BBD fits well to the experimental data. The optimum nickel ion, reducing agent and stabiliser concentrations of 29.86, 0.77 and 30.92 g L−1 were obtained from BBD for the maximum hardness of 592 HV. The local optimum values obtained from BBD were compared with global optimisation techniques, SA and GA, and the values were validated through experiments carried out in triplicate. The maximum hardness from local and global optimisation techniques was identical, with negligible change in the values of optimised process parameters. X-ray diffraction and scanning electron microscopy methods were used to examine the elemental composition and surface morphology, respectively, before and after heat treatment.

Large-scale synthesis of nitrogen doped graphene/carbon nanotube composites by solid-state pyrolysis of nickel phthalocyanine and its synergistic effect for microwave absorption properties

Here a hydrogen-free, solid-pyrolysis of nickel phthalocyanine was developed to produce graphene/carbon nanotube composites doped with 3 ~ 5 at% nitrogen atoms. By changing the nickel ion content in the organometallic precursors, the carbon nanotubes with bamboo-like morphologies, uniformly dispersed on the graphene sheet were obtained in a controlled fashion. The graphene/carbon nanotube composites exhibited a synergistic effect for the microwave absorption properties. A broad absorption bandwidth (RL < − 10 dB) of 5.1 GHz (12.9 ~ 18.0 GHz) was achieved with the thickness of 1.5 mm.

Metal Release of Standard and Fake Orthodontic Braces: An In Vitro Study

INTRODUCTION: The growing demand for orthodontic braces among Malaysians has led to the development of fake braces. These fake braces services are illegal and their brackets are reported to be of inferior quality. Fake braces are constantly being exposed to the saliva intraorally, hence they are susceptible to corrosion. This study was conducted to investigate the release of metal ions as a result of corrosion from standard and fake orthodontic braces immersed in artificial saliva of different pH. MATERIALS AND METHODS: A total of six different types of brackets (three from standard and three from fake braces) were immersed in containers containing 5 mL of artificial saliva of pH 4.9 and pH 7.8. The samples were collected for analysis on day 1, day 14, and day 28 using Inductively-Coupled Plasma Mass Spectrometry (ICPMS) to evaluate the amount of metal ion released. Statistical analysis was performed to isolate the significant difference of metal ions released between two types of braces in different pH solutions. RESULTS: The release of aluminum, nickel, chromium, manganese and copper were observed and analyzed. Fake braces released the highest concentration of chromium, manganese, and nickel ions in both artificial saliva as compared to standard braces. Brackets immersed in pH 4.9 released a higher number of ions compared to pH 7.8. CONCLUSION: This study showed that fake braces released the highest concentration of metal ions as compared to standard braces. Both time and pH influenced the release of metal ions from orthodontic brackets.

Removal of nickel ions from synthetic wastewater by bulk liquid membrane

Heavy metals extraction and separation from industrial wastewater has becomes a majorconcern for both environmental and economic reasons. This paper describes a comparetive kinetic study ofthe removal and recovery of nickel ions from aqueous solutions by bulk liquid membrane (BLM) usingcoupled faciletated transport mechenisms and two carriers of diffarent chemical nature: tributyl phosphate(TBP) and di-2-ethylhexyl phosphoric acid (D2EHPA). Xylene oil was used as the liquid membrane phase.In addition, environmentall friendly materials such as vegetable oils (soybean oil) used as a suitablereplacement for the conventional organic solvents in this work. A comprahensive kinetic study was carriedout and effact of various parameters such as, pH of feed and stripping phase, initial concentration of metalions, concentration of extractant in the membrane phase and stirring speed were studied. The chelatingcharacteristics of EDTA was used as stripping agent as well as precipitating agent to enhance the transportefficiency of the nickel ions. The extraction and recovery efficiency were found as 80.89% and 87.80%respectively for nickel ions, At the optimum process conditions for transport of Ni(II) were found as follows:pH in the feed phase (4), pH in the stripping phase (8), initial concentration of nickel ions (120 ppm), carrierconcentration (12%) (v/v) TBP and stirring speed (125±10 rpm), respectively.