Search published articles


Showing 7 results for Bahramifar
Survey of Heavy Metals (Cd, Pb, Hg, Zn and Cu) Contamination in Sediment of Three Sites Anzali Wetland
M Khosravi, N Bahramifar, M Ghasempour,
Volume 4, Issue 2 (9 2011)
Abstract

Background and Objectives:Anzali Wetland is one of the most important aquatic ecosystems of Iran which is located in south-west of the Caspian sea. This Wetland provides a suitable and non-market price habitat for valuable fish and aquatic animals which have an important role in the life cycle of this ecosystem. This study reports the results of some heavy metals contamination monitoring in superficial water of the Anzali Wetland, Iran.
Materials and Methods: The samples were collected from three sites (east, center and west) of Anzali Wetland, in each site three stations existed and each sample replicated three times.
Results: The results showed high heavy metal levels in eastern site of wetland, where there were high levels of contamination. The mean of heavy metals concentration in sediment from Anzali Wetland were in order as Cd 157.023, Pb 3.646 and Hg 300.692 ng /g dried weight, Zn 186.953 and Cu 44.452 mg /g dried weight in eastern site. The concentration levels of heavy metals in three sites were in order as follows: Zn > Cu > Hg > Cd > Pb.
Conclusion: Concentrations of heavy metals in eastern zone reflected metal loadings from anthropogenic sources located at and in the vicinity of the sampling sites.


Determination of Mercury Concentration in Different Tissues of Coot (Fulica Atra), Mallard (Anas Platyrhynchos) and Great Cormorant (Phalacrocorax Carbon)
J Azami, A Esmaili-Sari, N Bahramifar,
Volume 4, Issue 4 (2 2012)
Abstract

Background and Objectives: The heavy metals pollution in aquatic ecosystems especially mercury, always makes concern about health of aquatic organisms. So, the purposes of this study were determination of total mercury in different tissues of the three species of the most important water birds at north of Iran and comparison with world health standards.
Materials and Methods: Generally, 51 birds were captured randomly. Then, samples of feather, liver, kidney and muscle were taken and the mercury concentrations were determined by Advanced Mercury Analyzer (Model Leco, AMA 254).
Results: The most amount of accumulated mercury was in great cormorant's liver (piscivorous species). Means of mercury concentration in liver of great cormorant, mallard, and coot were 14.80, 2.05, 0.18 in kidney 12.00, 1.90, 0.17 in feather 6.57, 1.09, 0.23 and in muscle 8.67, 0.26, 0.09 mg/kg dry weight respectively. Means Comparison showed significant difference among all tissues (P < 0.05), But there were not significant difference between sexes (P > 0.05)
Conclusion: The levels of accumulated mercury in all tissues of great cormorant were more than the established limits by WHO, FAO and EPA. The other species had less use limitation, but mercury concentration in mallards was considerable. These results can be a serious warning for consumers these birds, especially vulnerable people.


Migration of bisphenol A and nonylphenol from mineral water bottles and disposable plastic containers into water at different temperatures
Ali Kazemi, Habibollah Younesi, Nader Bahramifar,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objectives: bisphenol A and nonylphenol are xenoestrogen materials used as a monomer of plastics in widely volume in the production of plastic materials especially mineral water bottles and disposable plastic containers. In this study, we investigated the potential of migration of bisphenol A and nonylphenol from disposable plastic containers into water at different temperatures and also from mineral water into water at different temperatures. Materials and Methods: We conducted bisphenol A and nonylphenol extraction from each sample through liquid-liquid extraction. For identification and quantitative determination of bisphnol A and nonylphenol, we used gas chromatography equipped with mass detector, and for quantitative determination of these two compounds, we used high-performance liquid chromatography equipped with fluorescence detector. Results: We found that increasing temperature increased significantly the rate of migration of these two compounds in the water. Moreover, it was revealed that only the presence of bisphenol A in water of mineral water bottles was detected and the increase in temperature also increases the rate of migration bisphenol A into water. Conclusion: In general, results of this study showed that improper storage of mineral water bottles and also use of disposable plastic containers for hot drinks would result in increasing consumer exposure to these compounds.
Concentration of total and organic mercury and antagonistic relationship between selenium and organic mercury in the sediments of the international Anzali wetland
S Alidoust, N Bahramifar, A Esmaeli Sari,
Volume 10, Issue 1 (6-2017)
Abstract

Background and Objective: Mercury (Hg) is considered as a global pollutant that is widely dispersed in the environment. Monitoring of total mercury (THg) concentration in the sediments without determination of organic mercury (OHg) and selenium (Se) is an unreliable approach to evaluate the precise toxicological effects of Hg. In the present study, concentrations of THg, OHg and Se in the surface sediments of the eastern and western parts of Anzali wetland were investigated. In addition, the correlation of THg and OHg with Se and total organic carbon were analyzed.

Materials and Methods: Forty surface sediment samples were collected from the eastern and western parts of the wetland. Analysis of total and organic mercury in the sediment samples were done with Advanced Mercury Analyzer and the concentration of selenium was measured using inductively coupled plasma atomic emission spectroscopy (ICP-OES).

Results: The average concentrations of THg in the East and West wetlands were 109.53 and 68.39 ng/g dw, respectively. The average concentration of THg in the sediments of the eastern part of Anzali Wetland was significantly higher than that of the western part (P<0.001). The mean concentrations of OHg in East and West wetland were about 34.91 and 28.84 ng/g dw, respectively. There was  no significant relationship. The ratio of OHg to THg showed significant differences in the two studied areas. The average concentrations of Se in East and West wetlands were 156.25 and 163.75 ng/g dw, respectively. There was a significant negative correlation between the concentration of selenium and organic mercury in sediments of  the western part of  wetland (P<0.05).

Conclusion: The THg concentration in the sediments of Anzali wetland was lower in comparison to other studied regions of the world. However, the percentage of OHg in the Eastern and Western part of wetland was high. Therefore, bioavailability and toxicity of Hg would be high in the sediments and aquatic environment. In this study, in spite of high molar ratio of Se to THg, there was relatively high content of OHg. We recommend to measure the various Se-species that are effectively bound to inorganic Hg and to determine the amount of Se and Hg in aquatic organisms.


Assessment of the metals and metalloids level in street dust of the east and west of Tehran
S Mazloomi, A Esmaeili - Sari, N Bahramifar, M Moeinaddini,
Volume 10, Issue 2 (9-2017)
Abstract
Background and Objective: Street dust is considered as one of the important sources of particulate matters and heavy metals in the atmosphere. The goal of this study was to assess the heavy metals pollution in street dust of Tehran and evaluate their ecological risk.
Materials and Methods: The sampling of street dust was carried out in two areas at the east and west of Tehran. After preparation of samples, the concentration of heavy metals was measured by ICP-MS. The pollution level of heavy metals in the street dust was assessed using geo-accumulation index (Igeo), pollution index (PI), integrated pollution index (IPI), enrichment factor (EF) and ecological risk index (RI).
Results: The results of the calculations of the indices showed that the street dust in both studied areas was non-polluted with Li, Al, Ti, V, Cr, Mn, Fe, Ni, Sr and Ba. The origin of these elements was mainly natural sources. However, Cd, Cu, As, Zn, Sn and Pb had medium to high level of contamination. These elements had a very high to extremely high enrichment in both areas. Their origin was mainly anthropogenic sources. The ecological risk index indicated a moderate ecological risk for the east and a low ecological risk for the west area.
Conclusion: The higher level of lead in the East is the main reason of higher ecological risk of this area. Therefore, the heavy metals pollution of the street dust, especially lead and its enterance into the environment, should be considered in this area.
 

Optimization of activated carbon production by using K2CO3 at different temperatures for the removal of Reactive Black 5 dye from aqueous solutions
M Bijari, H Younesi, N Bahramifar,
Volume 10, Issue 4 (3-2018)
Abstract
Background and Objective: Reactive dyes are the newest dyes in textile industry. They may cause environmental problems. The aim of this study was to remove Reactive Black 5 (RB5) in aqueous solutions with activated carbon that was made from grape wood.
Materials and Methods: The activated carbon was synthesized by potassium carbonate with impragnation ratios of 1:0.25 at different temperatures (600,650,700,750,800,850,900)°C. Experiments on dye adsorption were done under the same conditions including pH of 2, adsorbent dose of 0.025 g/L, initial dye concentration of 250 mg/L, volume of 100 mL, and contact time of 120 min. Then, the absorption RB5 in a bathc mode was done using the optimized activated carbon. The trends of pH, absorbent dose, initial concentration, temperature, retention time, parametrs were studied. The BET and SEM techniques were used to characterize the activated carboon. Finally, the equilibrium, synthetic and thermodynamic studies were done for RB5.
Results: The results  showed that the activated carbon sample that was synthesized under the imprenation ratio of 1:0.25 and  temperature of 900 oC had a  surface area 1670 m2/g. Moreover, the total pore volume was 1.134 cm3/g  and 68% of the total pore size were within mesoporous zone. The highest adsorption capacity was observed at the optimum condition. The optimum condition with the maximum adsorption capacity for RB5 was pH of 2, adsorbent dose of 0.035 g/L and temperature 45 °C. According to the equilibrium test results RB5 followed the Freundlich model. of the kinetic adsorption results showed that RB5 showed a pseudo-second-order kinetic model. According to the thermodynamic studies, it seems that RB5 absorption process was  an endothermic, non-spontaneous and physical sorption process.
Conclusion: The study showed that the produced-activated carbon from grape wood had a great potentioal for removing RB5 from aqueous solutions.
 

Photocatalytic degradation of rhodamine B dye from aqueous media using imide conjugated polymer photocatalyst under visible light
Raziyeh Zandipak, Nader Bahramifar, Habibollah Younesi, Mohammad Ali Zolfigol,
Volume 17, Issue 4 (3-2025)
Abstract
Background and Objective: Dyes are significant pollutants that pose serious hazards to humans, animals and other organisms. They are not biodegradable through aerobic treatment processes, making their removal from industrial wastewater through photocatalytic processes essential. This research aimed to synthesize an imide-conjugated polymer photocatalyst for the first time and evaluate its effectiveness in removing Rhodamine B dye from aqueous solutions.
Materials and Methods: In this applied research, an imide conjugated polymer was synthesized and employed as a photocatalyst for the removal of Rhodamine B from aqueous solutions. The polymer was characterized using Scanning Electronic Microscopy (SEM), Transmission electron microscopy (TEM), Atomic force microscopy (AFM), X-Ray Diffraction (XRD), Thermogravimetric Analysis, Fourier transform infrared spectroscopy (FTIR), and Diffuse reflectance spectroscopy (DRS) methods. The study also assessed the influence of variables, including pH (4-9), photocatalyst concentration (0.01-0.04 g/L), and contact time (0-120 min), on the removal efficacy of Rhodamine B.
Results: The findings indicated that removal efficiency increased to 99% at a contact time of 45 minutes and a photocatalyst concentration of 0.02 g/L. The optimal pH for Rhodamine B removal was found to be 7.
Conclusion: The imide conjugated polymer proved to be an effective and accessible photocatalyst for the removal of rhodamine B from industrial wastewater under visible light.
 

Page 1 from 1     

© 2025 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by: Yektaweb