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Showing 6 results for Azari
Efficiency of powder activated carbon magnetized by Fe3O4 nanoparticles for amoxicillin removal from aqueous solutions: Equilibrium and kinetic studies of adsorption process
B Kakavandi, R Rezaei Kalantary, A Jonidi Jafari, A Esrafily, A Gholizadeh, A Azari,
Volume 7, Issue 1 (7-2014)
Abstract

Background and Objective: Extreme use of antibiotics and discharging them to the environment lead to serious consequences. Activated carbon is the most commonly adsorbent for these contaminants but its main drawback is difficulty of its separation. The objective of this study was synthesis of magnetic activated carbon by Fe3O4 and investigating its efficiency in adsorption of amoxicillin from synthetic wastewater. Materials and Methods: Materials and Methods: Physical and structural characteristics of the adsorbent synthesized were analyzed using SEM, TEM, XRD and BET techniques. The effect of factors like pH, initial concentration of amoxicillin and adsorbent, contact time, and temperature were investigated to determine thermodynamic parameters, equilibrium isotherms, and kinetics of adsorption process. Results: Physical characteristics of the magnetized activated carbon showed that Fe3O4 nanoparticles had the average size of 30-80 nm and BET surface area was 571 m2/g. The optimum conditions of adsorption were: pH=5, contact time=90min, adsorbent dose of 1g/L and temperature 200C. The equilibrium isotherms data showed that the adsorption process fitted both Freundlich and Longmuir models with the maximum capacity of 136.98 mg/g. The kinetic of the adsorption process followed pseudo second-order model. The negative values of &DeltaH0 and &DeltaG0 obtained from studying the adsorption thermodynamic suggested that amoxicillin adsorption on magnetic activated carbon was exothermic and spontaneous. Conclusion: The present study showed that the magnetic activated carbon has high potential for adsorption of amoxicillin, in addition to features like simple and rapid separation. Therefore, it can be used for adsorption and separation of such pollutants from aqueous solutions.


Synthesis and efficiency evaluation of magnetic nanocomposite of activated carbon- zero valent iron/silver (PAC-Feº/Ag) in phenol removal from aqueous solution
B. Kakavandi, M. Mokhtari, R. Rezaee Kalantari, E. Ahmadi, N. Rastkari, M. Fatehi, A. Azari,
Volume 7, Issue 3 (5-2014)
Abstract

Background and Objectives: Phenol is one of priority pollutants produced through leather, paint, resin, and pharmaceutical industries and it can contaminate groundwater after entering to the environment. Hence, it is necessary to use a suitable method for its removal. The aim of this study was synthesize and efficiency evaluation of magnetic nanocomposite of activated carbon powder-zero valent iron/silver (PAC-Feo/Ag) in the removal of phenol from aqueous solution. Material & Methods: Reduction method was used for converting bivalent iron to zero valent iron and co-precipitation method for depositing of iron on activated carbon. For coating silver on nano zero valent iron, rapid mixing at high temperature was used. The adsorbent was characterized using SEM, TEM, and XRD techniques. Then, the impact of pH, contact time, agitation speed, temperature, adsorbent, and initial phenol concentration were evaluated and optimized by one factor at the time method. Reaction kinetics and isotherms were also determined. Results: It was found that PAC-Feo/Ag has cubic and intertwined structure and has a diameter in the range from 40 to 100 nm. The optimum conditions for phenol removal by PAC-Feo/Ag were as pH=3, 90 min contact time, 200 rpm agitating speed and adsorbent concentration equal to 1 g/l. Isotherm and kinetic equations showed that the experimental data of phenol adsorption onto PAC-Feo/Ag are correlated to the Langmuir (R2>0.969) and pseudo-second order (R2<0.965) models, respectively. Conclusion: Under optimum conditions, modified adsorbent by zero valent iron and silver with maximum efficiency of 97% has quickly and effectively ability in removal of phenol and it can be easily separated from the solution sample by magnet because of its magnetic properties.


Study and Zoning The Karun River Sediment Contamination by alkylphenolic compounds as Endocrine disrupting compounds (EDCs)
A.a Babaei, Z Nazari, E Ahmadpour, M Hosseinzadeh,
Volume 7, Issue 4 (1-2015)
Abstract

Background and Objectives: alkylphenol poly ethoxylates (APnEOs) and their metabolites enter environment through discharging wastewater and are of particular concern due to their persistence, toxicity to aquatic organisms, and a potential endocrine disruptor. In this work, we focused on the determination of nonylphenol (NP) and nonylphenol polyethoxylate (NPnEOs) in sediment samples collected from Karun River, Khoozestan Plain, Iran. Materials and Methods: Sample collection of Karun River sediment was carried out on rainy and dry seasons from 10 hydrometric stations. The sediment samples were prepared and extracted using solid phase extraction procedure and were analyzed using HPLC-FLD. Results: We found that NP and NPnEOs concentrations in sediment samples of Karun River were 0.21-2.43 and 0.18-0.91 µg/g respectively. This study revealed that NP concentration in sediment samples of Karun River was higher than the other alkyphenolic metabolites. Conclusion: The results indicated accumulation of endocrine disrupting contaminants (EDCs) in the Karun river sediments. The results showed significant difference between mean concentrations of these compounds in the upstream and downstream stations of Ahwaz Megacity (p-value<0.05).


Catalytic degradation of Triclosan by using xenon light/GO @ TiO2 combination system: optimization of initial parameters
N Golchinpour, N Rastkari, R Nabizadeh Nodehi, M Abtahi, A Azari, E Iravani, K Yaghmaeian,
Volume 10, Issue 4 (3-2018)
Abstract
Background and Objective: Triclosan is one of the substances as anti-microbial that is used in many of these pharmaceutical products. This compound can affect human such as reduction of thyroid hormone levels, antibiotic resistant, and increasing skin cancer. This study evaluated the performance nanophotocatalysis process UV/Xe/TiO2-GO on triclosan removal from aqueous solutions.
Materials and Methods: Synthesis of TiO2@GO and its structure was analyzed by SEM, EDX and FTIR. The effects of pollutant concentration, catalyst dosage, and contact time on the removal of Triclosan were studied by DOE software according to response surface methodology. Analysis of variance test was considered for the influence of parameters. Optimum process condition was determined by desirability factor.
Results: Optimum conditions regarding concentration of pollutant, contact time, and catalyst dosage were determined as 0.205 g/L, 14.898 min, and 0.487 mg/L, respectively. Maximum removal efficiency in optimum condition was 97.542 percent. The catalyst dosage was the most effective parameter in removal of Triclosan.
Conclusion: Using of TiO2@GO and xenon lamp had acceptable efficiency for the removal of Triclosan. The use of Xenon lamps alone was economically affordable.  
 
Investigation of the efficiency of powder activated carbon magnetized with Fe3O4 nanoparticles in the removal of catechol from aqueous solutions by response surface methodology
S Fallah Jokandan, M Yegane Badi, A Esrafili, A Azari, E Ahmadi, H Tarhandeh, M Kermani,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: The activities of various industries produce a wide range of pollutants and toxic compounds. One of these compounds is the catechol, a cyclic organic compound with high toxicity and resistant to degradation. Therefore, the purpose of this study was to investigate efficiency of powder activated carbon magnetized with Fe3O4 nanoparticles in the removal of catechol from aqueous solutions by response surface methodology.
Materials and Methods: The co-precipitation method was used to synthesize magnetic powder activated carbon and its properties were analyzed by SEM and XRD analysis. Then, the effect of the parameters such as pH, contact time, absorbent dose, initial concentration of catechol and temperature on the efficiency of adsorption process were investigated using a response surface methodology (Box–Behnken). The residual concentration of catechol was measured by HPLC at 275 nm.
Results: The results showed that the maximum efficiency of the adsorption process was obtained at concentration of 20 mg/L, pH=3, contact time 90 minutes, at 25 °C and absorbent dose of 1.5 g/L. The study of isotherm and kinetics showed that the experimental data of the catechol adsorption process correlated with the Langmuir and pseudo-second order models, respectively. Thermodynamic study of the reaction also expresses the Exothermic and Spontaneous process.
Conclusion: The results showed that the adsorption process using powder activated carbon magnetized with Fe3O4 nanoparticles at acidic pH had better efficiency. As a result, the studied process as an effective, rapid and inexpensive method for removal of catechol from aqueous solutions is proposed. Due to its short reaction time, it is economically affordable process.
 

Air pollution tolerance index and heavy metals (Pb and Cd) bioaccumulation in selected plant species (trees, shrubs and herbs) in high-traffic areas of Yazd city
Behnam Nazari Alamdarloo, Asghar Mosleh Arany, Saeed Shojaee Barjoee, Hamidreza Azimzadeh, Bahman Kiani,
Volume 13, Issue 2 (8-2020)
Abstract 
Background and Objective: Urban traffic, while affecting human health, causes physiological and biochemical changes in plants. The aim of this study was to investigate the bioaccumulation potential of Pb and Cd and assess air pollution tolerance index for a number of plants grown high traffic areas of Yazd.
Materials and Methods: This cross-sectional, descriptive-analytical study was performed in both control and high traffic areas of Yazd city by random sampling of trees, shrub and herb species. After transferring the samples to laboratory, relative water content, pH of leaf extract, total chlorophyll and ascorbic acid content (the factors for calculating APTI) in plants were measured using standard methods. Furtheremore, Pb and Cd concentrations were measured to find their relation with APTI index in plants. All statistical analysis, including Kolmogorov–Smirnov test, ANOVA, Duncan test and Pearson correlation coefficient between the studied parameters, were performed in SPSS software version 22.
Results: The highest relative water content (84.73%) and ascorbic acid (5.98 mg/g) were measured in contaminated area for Canna indica and Rosa damascena, respectively. Also, the highest acidity (7.01) and total chlorophyll (1.48 mg/g) in the control area were measured for Verbena hybrida and Ligustrum vulgar, respectively. The highest air pollution tolerance values were recorded in Rosa damascena and Ligustrum vulgar. Moreover, the results obtained showed that APTI index was positively and significantly correlated to Pb, ascorbic acid and relative water content. 
Conclusion: According to the classification of air pollution tolerance index, two species of Rosa damascena and Ligustrum vulgar exhibited moderately tolerant to traffic pollutant. Therefore, based on ecological requirements of these two species, they can be used to develop green spaces in high-traffic areas of Yazd.  This study showed that Pb increased physiological response of the studied plants, while the plants did not exhibit a significant physiological response to the Cd element. The results also showed that the relative water content and ascorbic acid were more important in the air pollution tolerance index than other factors.

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