Showing 14 results for Asgari
Gh Ghanizadeh, Gh Asgari,
Volume 2, Issue 2 (16 2009)
Abstract
Backgrounds and Objectives: Dyes are organic materials with complex structures, toxic, carcinogenic, teratogenic,nonbiodegredable properties and!the most!important pollutants of textile industrial wastewaters. The goal of this study was to survey the feasibility application of bone char (BC) as a sorbent for the of methylene blue (MB) from synthetic wastewater.The sub goals of the research!were to determine!the adsorption isotherm, !effects of primary concentration of dye, adsorbent!dose, contact!time, and pH for the adsorption of MB with BC.
Materials and Methods: BC was prepared under laboratory conditions by using of electrical furnace at 400°C for 2h. The prepared BC was crushed and pulverized by standard ASTM sieves with range of 10-16mesh(1.18-2mm).The chemical composition and solid structure of BC was analyzed using X-ray diffraction(XRD) and scanning electronic microscopy (SEM). Measurement of the surface area was carried out by N2 gas via BET isotherm and Belsorb software. The concentration of dye was measured by photometric!method (663nm).
Results: Predominant!compositionof BC is calcium hydroxyl apatite (Ca5 (PO4)3OH with 14m2/g surface area. The results of this study showed that increasing of primary concentration of dye, adsorbent dose and pH (5 to12) would lead to increasing of adsorption/removal of MB dye.Equilibration of dye adsorption was reached at lapse of 2h andoptimum pH for adsorption of MB with BC found in the rage of 8.5-12.Adsorption of MB witht BC complies witht freundlich isotherm(R2:0.99).
Conclusion: Bone char is a cheap component that can be used as an adsorbent in water and wastewater treatment. Based on optimum pH of 8.5-12 found for the removal of MB and the fact that many of textile!industrial wastewaters have an alkaline pH, this adsorbent can be!used for the removal of dyes from these wastewaters.
S Nazemi, A.r Asgari, M Raei,
Volume 3, Issue 2 (6 2010)
Abstract
Backgrounds and Objectives : Vegetables are one of the most important components of daily food. Contamination of vegetables with heavy metals might ends to accumulate in the body, there for in this study the level of lead, chromium, cadmium, arsenic and zinc in cultural vegetables of shahroud suburb were measured in 1387.
Materials and Methods : In this cross-sectional descriptive study, 150 vegetable samples through 3 months, 50 for each month, were randomly harvested. Atomic absorption instrument was used to determine the amount of mentioned heavy metals after sample preparation, SPSS whit 0.05 was used for statistically data analyzing.
Results : For vegetables the average value of Pb, Cr and Cd in different vegetables were different from each other and P value was less than<0.001. There are no significant amounts of Arsenic concentration. The value of these metals with 95% acceptable level was in the range of satisfaction. Arsenic didn&apost have that much of error of its contamination
Conclusion : Except Zn and As other metals like Cr, Cd and Pb were above the standard zone by FAO&WHO. The wastewaters of urban and industrial facilities are the main reason for this problem.The best suggestion is using pure water for this purpose.
A.r Rahmani, M Solaimany Aminabad, Gh Asgari, F Barjasteh Askari,
Volume 3, Issue 4 (8 2011)
Abstract
Backgrounds and Objectives: High level of nitrate ion in the water resources cause some health and environmental problems. The aim of this research is to study nitrate removal by Zero-Valent Magnesium (ZVM) and MgCl2-modified pumice from aqueous solutions.
Materials and Methods: The pumice granules were modified by MgCl2 . The removal of nitrate was studied in a batch system. The pH, initial nitrate concentration and sorbent mass parameters and the Langmuir and Freundlich models were studied in the sorption of nitrate onto the pumice. The ZVM was also used in a bach system and the previous parameters were studied.
Results: The removal efficiencies of nitrate by ZVM at the the initial pH of 3, 5 and 7 with controlling the pH were 70%, 40% and 30% ,respectively. These values are much higher than the values of the condition during which the pH was not controled. The nitrate removal efficiency increased by increasing of initial nitrate concentration in a constant molar ratio of Mgo/NO3. The removal efficiencies of nitrate by the modified pumice at the the initial pH of 3, 6.5 and 10 (when pH kept under control) were 49%, 29% and 16%, respectively. By increasing of the initial nitrate concentration the removal efficiency increased. The values of R2 for the Langmuir and Freundlich models were 0.944 and 0.810, respectively. The sorption process Fitted well the Langmuir model with a monolayer sorption capacity of 0.68 mg/g.
Conclusion: The modified pumice had lower efficiency than ZVM in the removal of nitrate ion and its usage is not considerably affected bye the pH in comparison with ZVM. The pH of the solution should be cansiderd as a main controling parameter to get an optimum efficiency in the nitrate-ZVM process.
Faramarz Majidi, Somaieh Alavi, Reza Azimi Pirsaraei, Abdollah Heidary, Farhad Asgari,
Volume 5, Issue 3 (21 2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Electric and magnetic fields in the workplace are one of
the detrimental factors of power plants, transmission lines, electrical wires,
and electrical equipments, therefore, exposure to these fields might be harmful
for human health. This study aimed to provide information about intensity of
the electromagnetic fields at the high voltage electricity posts and its
comparison with the threshold limit value (TLV).
Materials and Methods: The study was conducted at one of the high voltage electricity post in Zanjan City
having 63, 230, and 400 KV power transmission lines. After identifying stations and measuring the intensity of these
fields, GIS maps were prepared and the values were compared with permissible
values.
Results: The measured
magnetic flux density at different parts of the high voltage post showed that
the lowest and highest intensity were
1.69 and 153.7 mG respectively which were lower than the ACGIH TLVs.The lowest
and highest intensity of the electric
field were 0.008 and 38.07 KV/m
respectively. The highest value belonged to the 400 KV line, which exceeds the
recommended ACGIH TLV (25 KV/m).
Conclusion: According
to the results, the magnetic field intensity was below the TLVs, but the
intensity of electric field measured in the 400 KV line was greater than its TLVs. Thus, the strategies and
recommendations for reducing exposure should be taken.
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Edris Hoseinzadeh, Mohammad Reza Samargandi, Mohammad Yosef Alikhani, Ghodratollah Roshanaei, Ghorban Asgari,
Volume 5, Issue 3 (21 2012)
Abstract
MicrosoftInternetExplorer4
Background and Objectives: Along with the rapid development of human life,
controlling harmful effects of
microorganisms would be unavoidable. The objective of this study was to
evaluate antibacterial efficacy of zinc oxide nanoparticles on different
microbial strains.
Material and Methods:
This experimental study was done using gram negative and gram positive bacteria
in nutrient media. Nanoparticle characterization was determined using X-ray
diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM).
Bacterial sensitivity to nanoparticles was tested using a disk diffusion test
and minimum inhibitory concentration (MIC). Time-kill studies and other tests
were carried out using 108 CFU/mL of bacteria at baseline. A point of zero
charge, pHzpc, of nanoparticle was investigated using the batch equilibration
method. Obtained data were managed by SPSS Ver.16 and were analyzed through the
Pearson, analysis of variance (ANOVA) and Student's independent t-tests. 0.05
was selected as significant level for all tests.
Results:
Characterization results from XRD, SEM, and TEM showed that particles are in
nano range and they do not contain any discernible crystalline impurity. The
average ZnO nanoparticles diameter was 20 nm. The pHZPC for ZnO was found to be
7.51. The P. aeruginosa strain exhibited larger diameter inhibition zone (DIZ)
to ZnO nanoparticle compared with other strains. Population of P.aeroginosa for
2 x MIC concentration was reduced to zero in the presence of nano ZnO within
150 min. The bacterial CFU had significant difference with contact time,
nanoparticles loading, and bacterial strain (P<0.001).
Conclusion: This study
demonstrated that antibacterial activity of ZnO can be a candidates for the
elimination of gram negative and gram positive bacteria, particularly in
nasocomial infection agent control.
Ali Reza Rahmani, Ghorban Asgari, Mehrdad Farrokhi, Mahdi Shirzad Siboni,
Volume 5, Issue 4 (15 2013)
Abstract
Background and Objectives: Dyes are one of the main environmental pollutants in the industrial effluents including textile industries, which are harmful for human health and environment. The purpose of this research was to investigate removal efficiency of Reactive Black 5 (RB5) dye using adsorption onto strongly basic anion exchange resin as an appropriate adsorbent.
Materials and Methods: After preparing materials and equipment required, removal efficiency of Reactive Black 5 (RB5) dye using adsorption onto strongly basic anion exchange resin was investigated with respect to the variation of pH, contact time, adsorbent dosage, and initial RB5 dye concentration in batch system. Then results were analyzed using Excel software.
Results: Our results showed that removal efficiency was decreased by increasing pH and initial RB5 dye concentration. Moreover, we found that the removal efficiency was increased by increasing adsorbent dosage and contact time. The kinetics and equilibriums data were explained acceptably by Langmuir isotherms and pseudo-second-order kinetics models respectively.
Conclusion: Overall, our findings revealed that removal of RB5 dye from aqueous solution using adsorption onto strongly basic anion exchange resin can be considered as an effective and quick method.
Mohaad-Reza Mohebbi, Koshyar Azam Vaghefi, Ahmad Montazeri, Mehrnoosh Abtahi, Sogol Oktahi, Reza Gholamnia, Fatemeh Aliasgari, Reza Saeedi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and objectives: In this research, an innovative drinking water quality index for assessing water resources as “modified drinking water quality index (MDWQI)” was developed and applied for evaluating all of the groundwater resources utilized for community water supply in urban areas of Iran during 2011. Materials and methods: Twenty-three water quality parameters and relevant Iranian standards for drinking water quality were selected as input parameters and benchmarks respectively. The MDWQI is calculated using three factors including the number of parameters that excurse benchmarks, the number of measurements in a dataset that excurse benchmarks and the magnitude of excursions. The MDWQI scores range from 0 to 100 and classify water quality in five categories as excellent (95-100), good (80-94), fair (65-79), marginal (45-64), and poor (0-44). Results: According to the MDWQI value, about 95% of the groundwater resources were in the good condition and the others were in the fair or marginal condition also the best and the worst water quality of water resources were observed in Ardebil Province and Qom Province respectively. The three parameters of fluoride, magnesium, and nitrate recorded the highest rates of violation to be 74, 32, and 13% respectively. Conclusion: The nationwide average score of the MDWQI was 85 (good description). This study indicated that the MDWQI and its sub-indices could describe the overall water quality of water bodies easily, reliably and correctly and have the potential suitability for extensive application all over the world.
Gh Asgari, A. R. Rahmani, A. R. Dehghanian, A. R. Soltanian,
Volume 7, Issue 1 (7-2014)
Abstract
Background and Objectives: In this experimental study, we used Analytical Hierarchy Process method to determine the best wastewater treatment process for dairy products factories. That is a multi-criteria decision making techniques and is based on expert knowledge. Materials and Methods: First, we formed the hierarchical structure and defined the main criteria and indicators. Then, we investigated the current situation of the treatment process through field observations and conducting influent-effluent analysis. Later, we converted the results obtained into quantitative indices. Then we weighted the main criteria, and their related sub criteria, depending on existing conditions we performed the experiments required and considered the experts ideas. Finally, Evaluation and prioritization of the options was conducted using Expert choice software. Then the sensitivity analysis was performed for main criteria and we evaluated the influence of the parameters weight change on the options. Results: In comparison with the main criteria, environmental criteria were more important followed by engineering criteria, economic and management criteria. Conclusions: Due to the influence of various parameters in choosing optimal wastewater treatment, Multi-criteria decision-making methods are necessary. Finally, “UASB + Aeration” was found to be the first priority followed by “Anaerobic filter + Aeration”, “Anaerobic lagoon + Aeration (2) + Sedimentation (2)”,” Anaerobic filter + Aeration (2) + Sedimentation (2)”. “Septic tank + Trickling filter + Aeration” system was found to be less preferable than other options.
M Leili, Gh Asgari, A. A Eskandari, L Borzoei, B Ramavandi,
Volume 8, Issue 3 (12-2015)
Abstract
Background and Objectives: Furfural is one of the toxic chemical compounds used in many industries such as petrochemical, food, paper products, pharmaceutical, etc., due to having some characteristics. Therefore, furfural could be found at different concentrations in the effluent from these industries and can enter the environment. Hence, the aim of this study was the assessment the efficiency of a low cost bentonite modified with cationic surfactant in the removal of furfural from aqueous solution.
Material and Methods: In this experimental study, bentonite was purchased from one of the Mines of Zanjan Province, Iran and then the efficiency of bentonite modified with the cationic surfactant CTAB (CTAB-Bent) was assessed in the adsorption of furfural from aqueous solution. Activated carbon (AC) was also purchased as commercial grade.
Results: Under optimum conditions, the removal efficiency of AC and CTAB-Bent was about 52 and 66%, respectively. For both adsorbents used in this study, the increase of contact time and sorbent dosage resulted in increasing the removal efficiency, but the removal efficiency was decreased with the increase of furfural initial concentrations. Regarding pH, the removal efficiency was the highest in relative acidic and neutral environment, (60 and 69% for AC and CTAB-Bent respectively). The kinetics studies revealed that the highest correlation coefficients were obtained for the pseudo-second order rate kinetic model. Adsorption data from both adsorbents was also fitted with Langmuir isotherm.
Conclusion: It was found that modified bentonite with CTAB as a natural adsorbent could have better efficiencies compared with activated carbon in the furfural removal, although more contact times is needed.
A Seid-Mohammadi, Ar Rahmani, Gh Asgari, S Bajalan, A Shabanloo,
Volume 10, Issue 1 (6-2017)
Abstract
Background and Objective: Main sources of 4-chlorophenol wastewater are petroleum industry, coal, paper and resin production. The aim of this study was to compare the performance of raw and cationic surfactant modified nanoclay in removal of 4-chlorophenol from aqueous solutions.
Materials and Methods: The influence of contact time, initial pH of solution, adsorbent dosage and 4-chlorophenol concentration as effective parameters in adsorption process and the influence of modification solution pH and surfactant loading rates were investigated. The modified nanoclay was characterized by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopy. Finally, the isotherm and adsorption kinetics were investigated.
Results: The removal efficiency of 4-chlorophenol was increased by increasing the initial pH from 3 to 11, so that after of 120 min, the absorption efficiency at an initial 4-chlorophenol concentration of 100 mg/L and 0.25 g adsorbate was 26 and 95.5 % at pH 3 and 11, respectively. Under the same conditions the removal efficiency for the raw nanoclay was 2 and 9% at pH 3 and 11, respectively. The FTIR and XRD analyses revealed that the nanoclay structural changed from hydrophilic to hydrophobic and the interlayer spacing was increased. The adsorption of 4-chlorophenol on raw and modified nanoclay was consistent with Langmuir and pseudo-second-order kinetics. The maximum absorption capacity of raw and modified nanoclay was 0.5 and 25.77 mg/g, respectively
Conclusion: The modification of nanoclay with cationic surfactant increased the adsorption efficiency of 4-chlorophenol.
Mohammad Rezvani Ghalhari, Faezeh Asgari Tarazooj, Mohammad Bagher Miranzadeh, Gholamreza Mostafai, Safa Kalteh,
Volume 13, Issue 3 (11-2020)
Abstract
Background and Objective: Vegetables are an essential part of our diet and a major dietary exposure route to heavy metals. Therefore, this study aimed to investigate the concentration and potential health hazards of heavy metals in the vegetables sold in Kashan markets.
Materials and Methods: 4 types of widelyraw-consumed vegetables, including parsley, coriander, basil, and fresh chives, were investigated in this study. Questionnaires were randomly given to individuals to determine vegetable consumption rate. Heavy metal were quantified using inductively coupled plasma- optical emission spectroscopy. Monte-Carlo Simulation was utilized to identify the associated health risks.
Results: Among tested heavy metals, Pb showed the highest concentration in parsley (4.8 ± 0.98 µg/g), coriander (3.8 ± 1.3 µg/g) and basil (3 ± 0.94 µg/g). Cr levels in fresh chives (2.8 ± 1.6 µg/g) was higher than other heavy metals. Also, the highest total hazard quotient values among examined heavy metals (Taking into account 95% confidence interval) were found for Pb (0.7), Cr (0.39), and Pb (1.034) in coriander, basil, and fresh chives, respectively.
Conclusion: Cr and Pb concentrations were generally beyond WHO/FAO guidelines in the samples. The THQ value for Pb in parsley was greater than 1, suggesting elevated adverse health effects due to parsley consumption.
Abdolmotaleb Seid Mohammadi, Ghorban Asgari, Reza Shokoohi, Parastoo Shahbazi,
Volume 13, Issue 3 (11-2020)
Abstract
Background and Objective: Considering the importance of alkalinity in pH regulation and its buffering role, in this study, the effect of inlet wastewater alkalinity on the efficiency of the anaerobic unit of the wastewater treatment plant. Moreover, a superior chemical compound in providing alkalinity to wastewater was investigated.
Materials and Methods: This study was performed in the treatment plant to determine the relationship between input alkalinity and removal efficiencies of COD, BOD5 and TSS. In order to determine the optimal alkali material for superb anaerobic wastewater performance, four common chemical substances including, NaOH, Na2CO3, Ca(OH)2 and MgO were selected and examined using One Factor At Time (OFAT) test method.
Results: According to the results maximum removal efficiencies were obtained 62, 66.6 and 71.2% for COD, BOD5 and TSS, respectively under alkaline condition of 1260 mg/L CaCO3. Furthemore, the optimal dose to supply one unit of alkalinity by Na2CO3, Ca(OH)2 and MgO were 0.53, 0.54 and 0.3 mg/L, respectively. These values were obtained 5 min contact time and mixing rate of 150 rpm. However, for NaOH the optimal dose supply was obtained 0.35 mg/L for 3 min contact time and mixing rate of 100 rpm.
Conclusion: In conclusion, the performance of anaerobic baffled reactor is highly related to the supply of influent alkalinity to the reactor. In addition, the use of MgO can be considered as a suitable alkaline substance to neutralize acidic wastewater and provide alkalinity for ABR system.
Forough Tajiki, Hossein Mohammad Asgari, Isaac Zamani, Farshid Ghanbari,
Volume 14, Issue 1 (5-2021)
Abstract
Background and Objective: Considering the fact that Iran is located in semi-arid climate and the harmful effects of dust storms on different ecosystems, this study aimed to identify and locate dust storms using fungal bio-aerosols (spores) and HYSPLIT model in southwestern region of Iran.
Materials and Methods: MODIS satellite images and HYSPLIT model were used to investigate the temporal changes of dust masses entering the Khuzestan province. Sampling was carried out from dust storms in Abadan and Khorramshahr cities and from the soil of the dried parts of Hur al-Azim and Shadegan wetlands in a two-month period (from May to July 2019).
Results: The results of numerical modeling show that Abadan and Khorramshahr cities were affected by dust storms of internal origin (from Hur-al-Azim wetland). After isolation of bioaerosols from air and soil samples, a total of 6 fungal genera were identified in soil samples and 6 genera in dust samples of internal origin by PCR-Sequencing method. Talaromyces, Alternaria, Penicillium and Aspergillus were identified as the predominant genera fungi in soil and air samples.
Conclusion: With 70% similarity of fungi found in soil and air samples, it can be concluded that the main source of fungi in Abadan and Khorramshahr is Hur al-Azim wetland.
Hasan Rahmani, Masoumeh Kazemi Mashkani, Faezeh Asgari Tarazoj,
Volume 14, Issue 3 (12-2021)
Abstract
Background and Objective: Hospitals are the center of infection transmission due to their special conditions. In order to reduce microorganisms from the equipment and in the hospital environment, disinfection and sterilization methods are required. The aim of this study was to investigate the types of disinfectants used in Kashan hospitals.
Materials and Methods: In this descriptive cross-sectional study, Kashan hospitals were selected in 2019 by simple random sampling and the relevant checklist was completed. The required information was collected and analyzed by interviewing an environmental health expert and observing different parts of the hospital and visiting the disinfectant warehouse.
Results: Due to the type of services provided and the possible resistance of the existing microorganisms, the studied hospitals use certain types of disinfectants. Bleach and sayasept- HP were the most widely used disinfectants.
Conclusion: The results showed that since the disinfection is performed by service personnel and help of health workers, informing them about the incidence and prevalence of nosocomial infections, loss of life and financial damage caused by these diseases is very important. In addition, the effective roles of these individuals in the optimal elimination of environmental pathogens and consequently the reduction of nosocomial infections are crucial.
