Showing 11 results for Zinc
M Mohammadian, J Nouri, N Afshari, J Nassiri, M Nourani,
Volume 1, Issue 1 (10-2008)
Abstract
Background and Objectives: Heavy metals processing industry has always been a major cause of concern which affects soils, surface waters, ground waters and river sediments contaminations. Thus, the Zanjan Zinc and Lead Smelting Plant has been considered as a potential source of contamination.
Mterials and Methods: This cross-sectional study has been conducted in February 2008 in the site region .The concentrations of Lead, Zinc and Cadmium have been assessed. The samples have been taken from 17 wells and atomic absorption spectrophotometeric method has been used to assess the samples. In order to find out and locate the exact situation of the wells under study, Global Positioning System instrument has been used. The correlation between the concentration of each metal and the distance of studied well from the plant has been assessed too.
Results: The findings of this study showed that lead and cadmium concentrations were 53% and 59% respectively out of the guideline values of World Health Organization.
Conclusion: The concentration of Zinc was lower than both national and international values in all samples. As the heavy metal concentration is very important for human health status, the other fields of study like heavy metal air pollution effects and related diseases and conditions should be studied and assessed.
N Daneshi, H Banejad, R Pirtaj Hamedani, H Farajee,
Volume 3, Issue 3 (10-2010)
Abstract
Backgrounds and Objectives: Due to copper and zinc elements toxicity, a greatly attention to removal of those in order to reduce environmental pollution exist. This experiment was conducted to investigate the study of the effect of gravity single layer rapid sand filter on heavy metals (zinc and copper) removal efficiency in aquatic condition in different phosphate concentration.
Materials and Methods: this study applied a gravity single layer rapid sand filter with silica sand media. Experiments conducted for all of the states of Cooper and Zinc concentration in 25, 75, 125 and 175 ppm at different phosphate concentration present by varied discharge. Each state of Solutions pumped on top of the bed and discharge adjusted. Samples taken fromeffluent then acidified immediately with nitric acid. Metals concentration perused by atomic emission spectrometer with ICP source. Collected data analyzed by SPSS software.
Results: Founds from this study shown that maximum removal efficiency for copper and zinc was 98.89%and 78.60%respectively effect of discharge,metal concentration and phosphate concentration factors in removal efficiency of zinc and cooper, discharge and phosphate concentration bilateral effect on cooper removal efficiency, phosphate concentration andmetal concentration bilateral on zinc removal efficiency, are significant in 1%. In addition, phosphate concentration and discharge bilateral effect, metal concentration and discharge bilateral effect are significant on zinc removal efficiency in 5%. Finally, bilateral effects of discharge and metal concentration also metal concentration and phosphate concentration have not significant effect on cooper removal efficiency.
Conclusion: Gravity single layer of rapid sandy filter with silica sand media in order to cooper removal in low concentration can be used successfully. This method in high concentration of cooper and also different concentration of zinc had not successful result but in this condition, may be use
of a series of filter with more depth
K Naddafi, M.r Zare, M Younesian, M Alimohammadi, N Rastkari, N Mousavi,
Volume 4, Issue 2 (9-2011)
Abstract
Background and Objectives: This study was conducted to investigate the toxicity of Titanium Oxide (TiO2) and Zinc Oxide (ZnO) nanoparticles as two of most widely used nanoparticles. The result of this study can help to designing environmental standard and legislations for nanoparticles.
Materials and Methods: Different concentrations of nano ZnO and TiO2 nanoparticles were added to nutrient Agar culture media. Then, definite numbers of Escherichia coli and Staphylococcus aureus bacteria were added to culture media and inhibition of these bacteria growth was measured in comparison to controls. Obtained data were analyzed to determine nanoparticles' EC50 and NOEC (No Observed Effect Concentration) using SPSS ver.16 and Probit standard test.
Results: 24-hours EC50 of nano ZnO using E. coli and S. aureus determined to be 5.47 mg/L and 2.38 mg/L respectively. In addition, 24-hours EC50 of nano TiO2 using E. coli and S. aureus determined to be 5366 mg/L and 3471 mg/L respectively. In the case of ZnO nanoparticles, no observed effect concentration determined to be 1.15 and 3.28 mg/L for E. coli and S. aureus respectively and in the case of TiO2 nanoparticles no observed effect level determined to be 1937 and 1184 mg/L for E. coli and S. aureus respectively.
Conclusion: This study showed that acute toxicity of nano ZnO is by far more than that of nano TiO2. Regarding the EPA acute toxicity criteria, nano ZnO is categorized as moderately toxic and nano TiO2 is categorized as practically non toxic. Hence, regarding the acute toxicity, in recommending exposure criteria and environmental disposal standards, compared to nano TiO2, nano ZnO requires more attention.
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.
Hossein Banejad, Atieh Zarei, Ali Akbar Safari Sinegani, Farshad Dashti,
Volume 7, Issue 2 (10-2014)
Abstract
Background and Objectives: Reuse of treated wastewater in agriculture is becoming more attractive due to the growing demand for water, particularly in arid and semi-arid regions like Iran.In some areas, industrial wastewaters distribute arsenic in the water and vegetables, among the other plants, are mainly irrigated by municipal and industrial wastewater. This study aimed to evaluate the outcome of radish irrigation using water contaminated with arsenic and zinc and to measure the zinc concentration in the edible parts of radish plant. Materials and Methods: The experiments were designed in the form of a factorial completely randomized design with three replications in which radishes were planted in pots about five kilograms. Arsenic concentration at four levels (0, 100,300 and 600 µg/l) and zinc concentration at three levels (0, 10, and 50 mg/l) were added to the irrigation water. The pots were equally irrigated once every 3 to 4 days. After harvesting and laboratory operations, zinc concentration was measured using atomic absorption spectroscopy. Results: The study indicated that zinc concentration in radish tubers is correlated with the concentration of zinc in water. The results of the analysis of variance table for the effect of zinc and arsenic-contaminated irrigation water on zinc concentration in radish roots, tubers and leafs show only one treatment (zinc concentration in water) on the property is significant at 5 and 1%. The results of the comparison table revealed that Zn uptake was decreased with increasing arsenic up to 300 µg/l. Conclusion: It was found that zinc concentration in radish roots, tubers, and leafs is correlated with the concentration of zinc in water. Moreover, there was a competition between the absorption of zinc and arsenic in plants. With increasing arsenic in irrigation water, transition of Zn was reduced to aerial part.
H Irvani, H Shojaee - Farah Abady, M Shahryari, M Nakhaei Pour,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: Styrene monomer is a volatile organic compound that is used in the various industries. Due to the hazardous effects of this chemical substance on the environment and humans, control and elimination of this vapour is necessary. Therefore, the aim of this study was to remove the styrene vapors from air flow using photocatalytic activity of zinc oxide immobilized on ZSM-5 zeolite.
Materials and Methods: In this experimental study, the fabricated catalysts were characterized using analysis of BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Dynamic Concentrator System were used to generate styrene vapors at a certain concentration and flow, and then removal efficiency of the styrene vapors was investigated using UV/ZnO and UV/ZSM-5/ZnO.
Results: The results of XRD analysis and SEM images showed that produced zinc oxide had nano dimensions. In addition, these nanoparticles was successfully stabilized on ZSM-5 zeolite. The results of the photocatalytic removal showed that ZnO and ZSM-5/ZnO catalysts at the concentrations of 50 ppm eliminated the styrene vapor 14% and 37%, respectively.
Conclusion: Findings of this study showed that stabilization of zinc oxide nanoparticles on ZSM-5 zeolite had an ssynergistic effect on the photocatalytic degradation of styrene. According to this finding, the use of adsorption-photocatalyst hybrid systems can be an appropriate technique to remove styrene vapors and other similar pollutants.
F Akhlaghian, H Azadi,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: All around the worlds, wastewater containing dye pollutants are considered serious problem. Rhodamine B dye which is used in textile, leather, drug, and cosmetic industries exert carcinogenic and strong toxic effects. The aim of this research was to remove of Rhodamine B dye by nanowires of zinc oxide doped with lanthanum.
Materials and Methods: In this work, nanowire of zinc oxide doped with lanthanum was synthesized by hydrothermal method. The obtained photocatalyst was characterized by XRF, XRD, and SEM method. Effects of batch process variables such as pH, initial concentration of Rhodamine B, and photocatalyst dose were investigated. The kinetics of the reaction was also studied.
Results: The SEM images showed a hexagonal structure of ZnO, and La/ZnO nanowires. XRD results also confirmed the formation of ZnO with wurtzite hexagonal structure in both samples (ZnO and La/ZnO). The kinetics studies showed that the reaction was a pseudo first order. The apparent constants of ZnO and 2%La/ZnO nanowires were 0.0045 min-1 and 0.0074 min-1; respectively. In a batch experiment, the degradation yield of 99.8% was obtained at operating conditions of 1.25 g/L of 2% La/ZnO photocatalyst, initial concentration of Rhodamine B solution 4.78 mg/L, and pH=9 under ultra violet irradiation for 4 h.
Conclusion: The nanowire of La/ZnO with an optimum load of lanthanum has a better photocatalytic activity than nanowire of ZnO for degradation of Rhodamine B in aqueous solution.
Mehran Riazian, Maryam Yousefpoor,
Volume 14, Issue 1 (5-2021)
Abstract
Background and Objective: In the present research, the synthesis and characterization of ZnS nanoparticles in zinc blend crystallite phase via hydrothermal method were reported. Advanced oxidation processes using nanophotocatalysts are one of the most efficient methods for removing the dyes with complex organic compounds from textile and industrial wastewaters. The photocatalytic performance of nanoparticles is drastically affected by their structural and optical properties. One of the most important features affecting the photocatalytic degradation of nanoparticles is their optical bandgap width, which is an important factor in the radiant photons in the visible and UV region and the production of active radicals to destroy the complex carbon pollutants. The optical bandgap width, like other properties of nanoparticles is affected by three important geometric parameters, including particle size, dimension and shape. It is also a function of synthetic chemistry, i.e. the precursors and the fabrication methods. The aim of the present study was to investigate the nanostructure of zinc-sulfide synthesized nanoparticles, optical properties and photocatalytic effect on the degradation of Methylene Orange dye.
Materials and Methods: The experiment of degradation of dye consisted of 70 mg of synthesized nanoparticles in 100 mL of dye solution containing 3.75 ppm of Methylene Orange dye at pH = 5.5. The experimental steps were repeated three times. Nanostructure characterization of three-dimension ZnS nanoparticles was specified by X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, transmission electron microscopy, Furrier transform infrared, ultraviolet-visible spectroscopy and N2 adsorption-desorption.
Results: The lattice characteristics such as density, specific surface area, size, strain, stress and deformation energy density are specified using Williamson-Hall (W-H) and Halder-Wagner (H-W) analysis. The photocatalytic degradation rate (k) of Methylene Orange was calculated to be 0.052 1/min, whilst after 60 minutes about 95% of the dye was photodegraded. The N2 adsorption-desorption calculations determined the mean pore diameter, specific surface area (SBET) and total porosity volume as 20.69 nm, 19.12 m2/g and 0.065 m3/g, respectively. The bandgap of fabrication ZnS has been evaluated from the Tauc's equation to be 3.47 eV. Compared with ZnS nanoparticles made by the hydrothermal method in the wurtzite crystallite phase (sample 2), the synthesized sample (sample 1) shows less lattice strain and stress, less crystallite size and also revealed the higher photocatalytic activity.
Conclusion: The pure zinc-sulfide nanoparticles without metal or ceramic dopants in the cubic zinc-blend crystallite phase are synthesized using the hydrothermal method. The precursors used in the synthesis of zinc-sulfide nanoparticles include zinc chloride and thioacetamide in the presence of oleic acid as a collecting agent. High photocatalytic activity of ZnS nanoparticles was confirmed by the degradation or dechlorination of Methylene Orange solution under UV light irradiation. Compared to similar studies, the results show that reducing the optical bandgap from 3.84 eV to 3.47 eV increases the degradation rate from 0.031 to 0.052. In this study, it was shown that synthesized zinc-sulfide nanoparticles by hydrothermal method, was able to decrease optical gap bandwidth and subsequently increased photocatalytic activity.
Maryam Razavi Mehr, Mohammad Hossein Fekri, Fatemeh Mohammadi Shad ,
Volume 14, Issue 2 (9-2021)
Abstract
Background and Objective: Due to the water shortages and the presence of industrial pollutants in water resources, wastewater treatment, especially colored wastewater, is essential. The aim of this study was to treat wastewater containing Methylene Blue dye using activated carbon nanocomposite/zinc oxide nanoparticles (ZnO/AC) obtained from canola oil waste by green method.
Materials and Methods: In the present study, the effect of different parameters (pH, Methylene Blue concentration, adsorbent amount, temperature and contact time) on the adsorption of Methylene Blue was investigated. Design of Experiment 7 software (Response Surface Method (RSM)) was used to evaluate the influence of various parameters on Methylene Blue removal.
Results: The results of the predicted experiments showed that the highest adsorption of Methylene Blue is at pH = 10, temperature 70 °C, contact time of 50 min, initial adsorption concentration of 10 mg/ L and adsorbent amount of 0.05 g. Under optimal conditions, ZnO/AC adsorbent was able to remove 98.22% of Methylene Blue from the aqueous medium.
Conclusion: Appropriate to the high potential of ZnO/AC nanocomposite in the removal of Methylene Blue pigment, it can be a good candidate for the removal of dye contaminants and wastewater treatment of textile factories.
Mohammad Hossein Nemati,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: Environmental pollution with heavy metals and consequently their entry into food chains leads to irreparable damage to human health. The aim of this study was to determine the concentration of heavy metals including copper, zinc, lead and cadmium in blood and milk of grazing livestock around Zinc industry in Zanjan province (VSIPZ).
Materials and Methods: A total of 10 samples of grazing blood and milk were taken in each of the four geographical directions of the desired location. Also, in order to compare the current situation in the study area with the non-polluted areas, the control area (Qarah Poshtlu area of Zanjan) was considered. Dry ash method was used to digest organic matter.
Results: The results showed that the concentration of copper in the blood of cows and sheeps and the concentration of lead in the blood of cows in the west of VSIPZ was higher than the control group (p <0.05). There was no significant difference between the study areas and the control in terms of zinc and cadmium concentration in blood samples. Copper concentrations in cows and sheeps milk were lower than the control group in the southern and eastern regions of the VSIPZ, respectively (p <0.05). Zinc and lead concentrations in sheeps’ milk were higher than the control in the south and west of the VSIPZ, respectively (p <0.05).
Conclusion: In general, the results implied that the accumulation of lead in sheeps’ milk in the west of VSIPZ is more than maximum allowable concentration and can endanger the health of consumers.
Mehrab Aghazadeh, Amirhesam Hasani, Mehdi Borghei,
Volume 15, Issue 3 (12-2022)
Abstract
Background and Objective: Based on its unique characteristics, oil industry wastewater must be treated before discharging into the environment. The study aimed to optimize the catalytic sonopraxone process in the treatment of petroleum wastewater using a statistical method.
Materials and Methods: The synthesis of Iron Oxide-Zinc Oxide was carried out by air oxidation and layer-by-layer self-assembly method. XRD, SEM, EDAX, FT-IR, BET, DRS, VSM and TGA techniques were used to investigate the structure. In this study, applied CCD method optimization of pH parameters, reaction time, ozone gas concentration, hydrogen peroxide concentration and catalyst amount in the process. In optimal conditions, BOD5 and TPH removal values, reaction kinetics and synergistic effect of mechanisms were studied. COD, TPH and BOD5 were measured by spectrophotometer (DR6000), GC-FID and incubator, respectively.
Results: The results indicated that the Fe3O4@ZnO structure is well formed. A quadratic model was proposed to model the process based on the correlation coefficient. Based on ANOVA analysis and p and f indices, the proposed model was reported to be significant. Optimum conditions include pH 6.4, ozone concentration 1.3 mg/L.min, hydrogen peroxide concentration 2.5 mL/L, reaction time 51 min and catalyst amount equal to 0.64 g/L. In these conditions, the amount of COD reduction was 82.3 and 70% theoretically and experimentally, respectively. Also, in optimal conditions, BOD5 and TPH removal rates were 90.5% and 85.8%, respectively. The kinetics of the process follows the kinetics of the first order (R2=0.98) and the presence of different mechanisms together causes a synergistic effect and increases the efficiency of the process.
Conclusion: This process can improve the quality of oil effluent based on COD, BOD5, and TPH removal.
