Showing 4 results for Nickel
Volume 9, Issue 4 (10-2010)
Abstract
Nickel is one of the essential elements (micronutrients) for plant growth. In this study, the effects of different concentrations of nickel, (0, 40, 80, 160, 320, 640 and 1280&mu M) and some environmental factors such as pH and Ca2+ concentration on the growth of seedlings of four wheat cultivars (Sardari, Zarrin, Alamout and C-73-20) were investigated. Moreover, the impact of high concentration of Ni on root sugar secretion has been assessed using sulphuric-phenol method .The results indicated that Alamout was more resistant than the other cultivars regarding to nickel stress. On the other hand, root and shoot tissues showed different growth responses to Ni and radical growth was more sensitive than shoot growth. Decreased pH increased the impact effect of nickel on shoot and root growth. Our study showed that increasing Ca2+concentration decreases Ni toxicity. Finally, Ni inhibited the leakage of soluble sugars from root tissue.
Mohammad Ghazi, Mehdi Hasanshah, , ,
Volume 12, Issue 4 (11-2013)
Abstract
Nickelate with general formula La2-xSrxNiO4 (x≈0.33) were synthesized by the sol–gel method. Then by changing the sintering temperature and growth parameters, particles with various sizes were produced. The crystal structure and physical properties of the prepared samples were investigated by X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), Energy dispersive X-ray spectroscopy (EDX) and field emission scanning electron microscopy (FE-SEM) and resistivity measurements from room temperature to low temperatures. The XRD results and investigation of the surface morphology show the lowest temperature to get a single phase tetragonal structure is 920°C. These data confirm the formation of single phase structure in samples sintered at higher temperatures. The particle size increases with increase in sintering temperature. The FE-SEM results show that the particles sizes are in range of 50nm to 2mm. The results of resistivity measurements versus temperature by fourprobe method indicate that the charge ordering transition temperature move to lower temperature with decrease in particle size.
Fatemeh Talebi Khalilmahalleh, Reza Marandi,
Volume 14, Issue 4 (6-2015)
Abstract
The environmental pollution of harmful toxic metals is one of the important issues in the world today. Nickel is one of the toxic heavy metals which if enters into the human body in high concentrations it will cause skin allergy, heart disease and various cancers. Therefore, there is need to remove Nickel from industrial wastewater. The purpose of this study was firstly to remove nickel from aqueous solutions with synthesized activated carbon from carrot remains and secondly to investigate the effect of variations of the adsorbent particle sizes on the equilibrium time and the removal efficiency. For this purpose, adsorption of Ni (II) ions on the adsorbent was studied in a batch process. Firstly, the activated carbon was prepared from carrot remains with particle sizes between 37 and 300 micrometers. The results showed that the maximum absorption efficiency occurs (100%) at pH of 6. Moreover, it was shown that with decreasing the adsorbent size from 300 to 37 µm, the equilibrium time will decreases from 130 to 20 min. Experimental data was best fitted onto pseudo-second order model. Langmuir and Freundlich isotherms equation were used to fit the adsorption isotherms. It is evident from this study that activated carbon is a suitable material for the uptake of Ni (II) from aqueous solutions.
Salman Ahmady-Asbchin, Naser Jafari,
Volume 15, Issue 1 (4-2015)
Abstract
Abstract
Methods of physical and chemical adsorption of heavy metals, has some disadvantages such as high cost and are ineffective at low concentrations. Methods for biological uptake of heavy metals in recent decades were considered. Among the biological adsorbent include: bacteria, fungi and alga, algae have the highest efficiency of metal uptake. This study determined that the main role in the uptake of metals, nickel (II) and cadmium (II) Alginic acid is responsible. Focus serratus brown alga, as adsorbent in this study used a cost-effective biological and biological uptake of cadmium and nickel ions simultaneously in a batch reactor has been studied. Surface structure of algae has been studied. Adsorption kinetics have been studied, the equilibrium time is about 300 minutes, the Langmuir adsorption isotherm using the equation can be interpreted as the maximum adsorption of about 0/85and 0/95mmol/g are, respectively, for cadmium(II) and nickel(II).
