Showing 8 results for Nickel
M Shirzad Siboni, M. T Samadi, A.r Rahmani, A.r Khataee, M Bordbar, M.r Samarghandi,
Volume 3, Issue 3 (10-2010)
Abstract
Backgrounds and Objectives: Industrial wastewater included the heavy metal is one of the important sources of environmental pollution. Hexavalent chromiumand divalent nickel are founded in plating wastewater which is harmful for human health and environment. Therefore, the purpose of this research is investigation of photocatalytic removal of hexavalent chromium and divalent nickel from aqueous solution using UV/TiO2 process in a batch system.
Materials andMethods: At first, reactor was designed. Then, optimumdosage of TiO2 was obtained equal to 1 g/L, with variation TiO2 dosage at constant pH and initial concentrations of hexavalent chromium and divalent nickel. The effect of pH, contact time and initial concentration of hexavalent chromium was studied at the constant amount of TiO2 (1gr/L).
Results: The result showed that photocatalytic removal efficiency increased with increasing reaction time and TiO2 dosage. In addition, it was found that removal efficiency of hexavalent chromium was decreased by increasing initial chromium concentration and pH. But, photocatalytic removal efficiency of nickel ion was increased and decreased by increasing of pH and initial nickel concentration, respectively.
Conclusion: The results showed that UV/TiO2 was an effective method in removal of hexavalent chromium and divalent nickel from aqueous solutions
R Fouladi Fard, A.a Ebrahimi,
Volume 3, Issue 4 (1-2011)
Abstract
Background and Objective: Nickel (II) and cadmium (II) are important in environmental pollutant. Biosorption of heavy metals can be an effective process for the removal and recovery of heavy metal ions from aqueous solutions because of the decrease in sludge problems, economical issues, high efficiency and compatibility with the environment.
Materials and Methods: power of wasted activated sludge have been contact with nickel (II) and cadmium (II) solutions in 0.25 and 0.75 milli molar invarious pHs and mixing pace, at 24-26 0C temperature on batch reactor system .After two hours (continuously 5-420 min in kinetic study) samples were analyzed with atomic absorption spectrophotometer.
Results:The kinetic study results show that equilibrium adsorption time for nickel (II) and cadmium
(II) reached within 2 hr, but the profile curve of cadmium (II) biosorption was smoother than nickel (II) biosorption. Both metals adsorption followed the Langmuir model and the maximum adsorption capacity (qmax) for nickel (II) and cadmium (II) was 0.195 and 0.37 milli mole per gram respectively. The increase in pH resulted in adsorption increase for both metals. For cadmium (II) at 0.25 and 0.75 mMinitial concentration there was no adsorption at pH 2 where as nickel (0.25 mM) adsorption was observed at the same pH. The optimum mixing rate for both metals was 200 rpm and this effect was more obviously in greater concentration.
Conclusion: Like othe biosorbents ,wasted activated sludge showed greater capacity for cadmium(II) biosorption than nickel (II). Cadmium (II) in modeling and biosorption characteristics study had more conformity than nickel (II).
Abdulreza Mashroofeh, Alireza Riyahi Bakhtiari, Mohammad Pourkazemi,
Volume 6, Issue 3 (12-2013)
Abstract
Background and objective: Metal pollution has always been a major cause of contamination of environment and is considered as a major concern for food health. Worldwide, sturgeons are an important source of food and income. In this study, the human health risk due to consumption of caviar and muscle of Persian sturgeon (Acipenser persicus) were evaluated by measuring the concentrations of cadmium, nickel, vanadium and zinc in caviar and muscle samples.
Material and Methods: A total number of 24 samples of Persian sturgeon were collected from two important sturgeon fishery zones in Guilan and Mazandaran Provinces and were stored at −20°C until chemical analysis. About one gram of each sample dried was added to 10 ml of concentrated (65%) supra-pure HNO3 (Merck, Darmstadt, Germany) in a Teflon PTFE tube and then it was incubated for 1 h at 40 °C in a hot block digester, followed by heating at 140 °C for 3 h. The samples digested were diluted to a measured volume using double deionized water. Samples were filtered through Whatman No. 1 filter paper, and the filtrate was stored until metal determination.
Results: Mean Cd, Ni, V and Zn concentrations in muscle tissues were 0.005 ± 0.002, 0.06 ± 0.03, 0.13 ± 0.04 and 7.49 ± 3.07 µg/g wet weight basis respectively. The mean Cd, Ni, V and Zn concentrations in caviar samples were 0.007 ± 0.006, 0.09 ± 0.07, 0.12 ± 0.15 and 21.23 ± 5.75 µg/g wet weight basis respectively.
Conculation: The mean concentrations of Zn, Cd and V in caviar and muscle samples were less than the permissible limits proposed by the United Kingdom's Ministry of Agriculture, Fisheries and Food (MAFF 2000) and World Health Organization (W.H.O.). The guidelines for Cd, V and Zn are 0.2, 0.5 and 50 µg/g wet weight respectively. Therefore, the measured concentrations for these particular metals are below the published guidelines, and the levels would appear not to constitute any threat to the human population that may consume sturgeon or caviar obtained from these study locations.
Ali Reza Keshtkar, Hossein Dastebashi, Morteza Ghasemi Torkabad , Mohammad Ali Moosavian,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objectives: Biosorption is a new and inexpensive technique in heavy metals removal and recovery from aqueous solutions. In order to evaluate the potential of this method for the removal of nickel ions, biosorption of nickel ions from aqueous solution was studied using Cystoseira indica biomass in a packed bed column. Materials and Methods: The uptake capacity of nickel ions was investigated using protonated biomass at different influent concentrations and flow rates. In addition, the experimental breakthrough curve obtained under definite experimental conditions was modeled using Thomas, Yoon & Nelson, Dose-Response, and Belter models. Results: It was found that increasing influent concentration from 58 to 100 mg/l led to the increase of driving force for mass transfer and uptake capacity raised from 55.84 to 95.69 mg/g. The investigation of flow rate effect showed when the process is intraparticle mass transfer controlled, a slower flow rate favors the sorption. In the case of external mass transfer control, a higher flow rate decreases the film resistance and leads to an increase in mass transfer. Modeling the experimental data revealed that the abovementioned models were suitable to predict the breakthrough curves, especially Dose-Response. Measurement of pH of the effluent solution indicated that ion exchange is one of the main mechanisms of nickel biosorption using this biosorbent. Conclusion: The results of this study are complementary of the batch equilibrium sorption experiments. Therefore, from process viewpoint, this biomass can be proposed in the sorption columns as a sorbent for nickel ions.
Z Esdaki, R Ansari, F Ostovar,
Volume 12, Issue 3 (12-2019)
Abstract
Background and Objective: Due to the existence of industries such as stainless steel, the presence of nickel (II) ions in water and wastewater has been reported at high concentrations. Removal of nickel (II) ions from wastewater and the environment are of primary importance. In this study, iron (III) oxide nanoparticles were studied as an adsorbent for removal of Ni (II) ions from water in the batch equilibrium system.
Materials and Methods: FT-IR, SEM and XRD techniques were used to characterize the structure of the sample. To determine the optimum adsorption, the effect of important parameters such as pH, contact time, adsorbent weight and initial concentration were investigated. Also, thermodynamic study (Gibbs standard energy variations, enthalpy and entropy), isothermal studies (absorption capacity) and kinetic studies (absorbent effect with time) were investigated.
Results: The results showed that the magnetic adsorbent had the highest removal efficiency of nickel (II) at pH 7, contact time 60 min, adsorbent dosage of 200 mg, and maximum removable concentration of 400 mg/L.
Conclusion: With thermodynamic studies, it was determined that the reaction was endothermic and the spontaneous process was controlled using the entropy factor (ΔG°=-2.7 KJ/mol, ΔS°=+165.17 J/mol.K). In order to better understand the mechanism of adsorption, kinetics studies were carried out using the pseudo-first-order and pseudo-second-order models. Then, Langmuir and Freundlich adsorption isotherms were investigated to determine the adsorption capacity, and it was found that the adsorption data were well fitted to Freundlich model and the maximum adsorption capacity was 43.5 mg/g, which indicated high adsorption capacity and its multi-layers.Then, Langmuir and Freundlich adsorption isotherms were investigated and it was found that the adsorption data were well fitted to Freundlich model and maximum adsorption capacity (qmax=43.5 mg/g) was obtained which indicates good adsorption capacity of adsorbent and its multi-layers.
Mohsen Shaban, Daryoush Yousefi Kebria, Marzie Razavi,
Volume 14, Issue 1 (5-2021)
Abstract
Background and Objective: Application of chemical fertilizers in agricultural industry is known as one of the methods of crop enhancement. However, chemical fertilizers application can lead to an increased risk of chemical pollutants entering the human food cycle. The aim of current research was feasibility study and evaluation of nickel from paddy soils in Lorestan province.
Materials and Methods: Sampling was done from 15 stations and randomly from rice cultivation areas in Silakhor plain of Lorestan province. Then, electrokinetic modification method was carried out in three reactors with lengths of 5, 10 and 15cm. After sample preparation, the initial and final concentration of nickel were measured and calculated using inductively coupled plasma - optical emission spectrometry (ICP-OES).
Results: The results showed that electrokinetic modification method was effective in reducing the concentration of heavy metals in agricultural soil samples and reduced the amount of nickel in soil to the permissible limits of the Iranian soil national standards (50 mg/kg). The initial values of nickel in paddy soil of composite samples were 108 mg/kg. Nickel maximum removal efficiency of 90.84% and 93.75% were observed in cathode and anode regions, respectively.
Conclusion: The health and quality of agricultural products depend on the use of safe soil within the limits of environmental standards. The results of this study showed that the EKR process is able to remove nickel from soil. As a result of the present process, nickel concentration has reached the permissible amount and even lower than the soil quality standard set by the Iranian Environmental Protection Agency.
Zohreh Akbari Jonoush, Abbas Rezaee, Ali Ghaffarinejad,
Volume 15, Issue 2 (8-2022)
Abstract
Background and Objective: This study aimed to provide an effective electro-catalytic system for the simultaneous reduction of nitrate and disinfection of contaminated water by the electro-catalytic performance of Ni-Fe/Fe3O4 cathode.
Materials and Methods: At first, the Ni-Fe electrode was synthesized by the electro-deposition process. Then its physical properties were analyzed by scanning electron microscopy (FESEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) analysis, and photoelectron X-ray spectroscopy (XPS). Simultaneous disinfection and reduction of nitrate were performed under the following conditions: 15 mg Fe3O4 nanoparticles, pH 6.5, NaCl 10 mM, 50 mg/L nitrate, 105 CFU/mL and current density 4 mA/cm2.
Results: According to the results obtained in the absence of nitrate, 100 % of Escherichia coli bacteria were disinfected after 12 minutes. In the presence of nitrate, the time of complete disinfection increased to 120 minutes. In the absence of bacteria, 83% of nitrate was removed in 240 minutes, and in the presence of bacteria, the nitrate reduction efficiency increased slightly to 88%. In the nitrate reduction process, nitrite (0.22 mg/L) and ammonium (3.6 mg/L) were produced. In the presence of bacteria, the amounts of nitrite and ammonium produced increased to 0.42 mg/L and 7.3 mg/L.
Conclusion: The results show the outstanding ability of Ni-Fe/Fe3O4 electrode in electro-catalytic reduction of nitrate and disinfection of contaminated water separately and simultaneously with high efficiency and high selectivity to nitrogen.
Mahboub Saffari,
Volume 16, Issue 3 (12-2023)
Abstract
Background and Objective: Nowadays, the use of biochar as a new and suitable adsorbent to remove inorganic pollutants from water sources has grown significantly. The present study was conducted to evaluate the effects of biochar physical modifications compared to unmodified biochar on nickel (Ni) removal efficiency in aqueous solutions.
Materials and Methods: After the production of cypress cones biochar (RB), biochar particles (<164 µm) were crushed into very small (<26 µm) dimensions (BMB) using a planetary ball mill and after evaluation their various properties by SLS, BET, FTIR and SEM techniques, their application (RB and BMB) in optimizing the Ni removal from aqueous solutions were evaluated using the response surface methodology (RSM: Box-Behnken design).
Results: Based on the results, the physical modification of biochar (BMB) decreased the particle size by 6.2 times, increased the specific surface area by 4.9 times, increased (containing oxygen) and decreased (aliphatic and OH stretching groups) of specific functional groups and finer surface morphology, compared to RB. The use of BMB in the aqueous solution caused an increase of 9.7% (on average) in the removal of Ni compared to the RB sample. The fitting of the data obtained from Ni removal in the Box-Benken model in both adsorbents shows the appropriate prediction of this model in the optimization of Ni removal from aqueous solutions.
Conclusion: According to the results of this research, the physical modification of biochar, as a simple, cheap, and environmentally friendly method, due to the increase in the efficiency of Ni pollutant removal, can be introduced as a suitable method in the activation of biochar, which further research is required based on the type of biochar and various pollutants.
