Search published articles


Showing 6 results for Kamani
Survey of Arsenic Removal fromWater by Coagulation and Dissolved Air Floatation Method
F Kord Mostafapour, E Bazrafshan, H Kamani,
Volume 3, Issue 3 (4 2010)
Abstract

Backgrounds and Objectives:Arsenic is one of the most toxic and dangerous elements in drinking  water that with increase in its application in agriculture, development of applications in agriculture, livestock, medicine, industry and other cases its entry to water resources and environment is much easier.Arsenic is a poisonous, cumulative substance and inhibitor of SH group enzymes and various studies revealed a significant correlation between high concentrations of arsenic in drinking water and liver cancer, nasal cavity cancer, lungs, skin, bladder and kidney cancer in men and women and prostate and liver in men. The aim of this was survey of arsenic removed from water using dissolved air floatation mechanism.
Materials and Methods: At present study in first step for determination best conditions of arsenic removal by dissolved air floatation method, optimum amount of coagulants determined and then synthetic solution of arsenic (50, 100 and 200 µg/L) prepared using sodium arsenate. In third step arsenic removal efficiency under various variables such as arsenic concentration, flocculation and floatation time and saturation pressure were analyzed. Finally residual arsenic concentration was determined by the silver diethyl dithiocarbamate method.
Results:Effect of optimum condition on arsenic removal efficiency at various initial concentration 50, 100 and 200 µg/Lshowed that the best coagulant for removal of arsenic is polyaluminumchloride. Also maximum efficiency (99.4%) was obtained in initial concentration equal 200 µg/L.
Conclusion: It can be concluded that dissolved air floatation method with poly aluminum chloride as coagulant have high efficiency for arsenic removal even at high concentrations and therefore this method can be used for removal of arsenic from water as a suitable and safe option.


Survey on Removal of Tetracycline Antibiotic from Aqueous Solutions by Nano-Sonochemical Process and Evaluation of the Influencing Parameters
M Hoseini, Gh.h Safari, H Kamani, J Jaafari, A.h Mahvi,
Volume 8, Issue 2 (8-2015)
Abstract

Background and Objectives: Among the different types of antibiotics, tetracycline antibiotics are the second most common group around the world that their entrance into domestic sewage can result in contamination of water sources. The aim of this study was to investigate the efficacy of the nano-sonocatalytic process on removal of tetracycline antibiotics from aqueous solutions. Materials and Methods: In this study, the effectiveness of ultrasonic irradiation without and with TiO2 nanoparticles and hydrogen peroxide were studied in tetracycline antibiotics removal. For this purpose, a reactor different concentrations of tetracycline was exposed to two irradiation frequencies of 35 and 130 KHz. Concentration of residual antibiotic was measured using HPLC equipped with a C18 reverse phase column and a UV detector. Results: It was found that the efficacy of ultrasonic irradiation alone in removal of this pollutant was negligible and at the best conditions only 20.3% removal was achieved at the frequency of 35 KHz. Addition of TiO2 nanoparticles improved the removal efficiency the removal rate increased with the increase in TiO2 concentration until 250 mg/L, after which it remained approximately stable. The best removal efficiency was achieved by adding 100 mg/l hydrogen peroxide to US/TiO2 process at pH 4 in which 94.3% removal was achieved after 60 minute. Conclusion: The results of this study showed that the sonocatalytic process using TiO2 nanoparticles and along with adding H2O2 as an oxidant is very effective and can be used for removal of tetracycline antibiotics from aqueous solutions.


Factors affecting the concentrations of heavy metals in precipitation of Tehran using factor analysis method
H Kamani, M Hoseini, G.h Safari, A.h Mahvi, H Zarei,
Volume 8, Issue 4 (3-2016)
Abstract

Backgrounds and Objectives: Quantity of trace metals in the wet precipitation can illustrate the environmental pollution of different urban areas. Up to now, there is no study regarding the chemistry of wet precipitation in Tehran .The objectives of this study are: measurement of heavy metal concentrations and identification of the main factors affecting the heavy metal concentrations in wet precipitation using factor analysis method.

Materials and Methods: This was a cross-sectional study in which measurements of heavy metals were performed in 53 wet precipitation samples collected from a central site of Tehran City, capital of Iran. The samples were collected during November to May in 2010, 2011 and 2012 on the roof of the student’s dormitory building of Tehran University of Medical Sciences and then the concentration of heavy metals in each sample was measured with ICP-MS.

Results: pH ranged from 4.2 to 7.1 with a mean value of 5.1 indicating in acidic range. Result of EF calculations revealed that samples were not enriched with Fe and Cr but were enriched with Zn, Cd, Ni, Pb and Cu. Factor Component Analysis with Varimax normalized rotation showed Al, Fe and Cr are originated from crustal source and Zn, Cd, Ni, Pb and Cu are originated from anthropogenic sources. 

Conclusion: EF and acidic pH values indicate Tehran is under the influence of extremely anthropogenic activities. Large number of vehicles and industrial activity in the city are undoubtedly responsible for the emission of a wide range of pollution.


Efficiency evaluation mesopore sillica nanoporous materials in removal of cephalexin from aqueous solution by response surface methodology
H Kamani, Ah Panahi, Sd Ashrafi, F Kord Mostafapour, Ns Omrani Gargari,
Volume 10, Issue 3 (12-2017)
Abstract
Background and Objective: Extreme use of antibiotics and discharging to the environment lead to serious consequences. Mesoporous silica such as MCM-41 material is widely used to absorb contaminants from the aqueous solution. The aim of this study was to evaluate mesoporous synthesis of MCM-41 and its efficacy for removal of the antibiotic cephalexin from aqueous solution.
Materials and Methods: Physical characteristics and absorbent structure synthesized by techniques BET, FTIR and XRD were analyzed. The effect of variables such as pH values (3, 7, 11), the dose of MCM-41 (200, 500, 800 mg/L), initial concentration of cephalexin (50, 75, 100 mg/L), contact time (30, 60, 90 min), and process temperature (20, 30, 40 0C) on absorption of cephalexin were studied. In order to achieve the optimal experimental conditions, response surface methodology (RSM) model was used.
Results: The results showed that pH (p=0.0001), adsorbent dose (p=0.0001), initial concentration of cephalexin (p=0.0001), contact time (p=0.01), pH2 (p=0.0002) and pH (p=0.04) and initial concentration had a significant impact on the response variable. The optimum removal condition based on analysis of variance and the model was at the reaction time 90 min, pH 3, initial concentration 50 mg/L and adsorption dose 600 mg/L. Under these conditions, the removal efficiency of 81.1% was achieved.
Conclusion: The results showed that adsorption process with the mesoporous MCM-41 had a high efficiency on the removal of cephalexin from the aqueous environments.
 

Non-carcinogenic risk assessment of Hg and Cu in streets dusts of Zahedan city
M Moradi Baseri, H Kamani, Sd Ashrafi, E Bazrafshan, F Kord Mostafapour,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: Street dust is an important factor in urban pollution which consists of soil, particulate matters and heavy metals. At present, over half of the world’s population lives in urban areas. Therefore, this study aimed to investigate health risks of heavy metals in street dusts in Zahedan.
Materials and Methods: The samples of street dust were collected in Zahedan. After preparation, the samples, were injected to ICP-MS for determination the amount of Hg and Cu. According to the measured concentrations, Hazard quotient (HQ) and hazard index (HI) were calculated to evaluate the health risk assessment.
Results: Results showed that Hazard quotient for both Hg and Cu was less than 1 for children and adult. HQ for Hg and Cu was in order of HQingestion >HQdermal >HQinhalation> HQvapour for adults and HQvapour > HQingestion > HQdermal > HQinhalation  for children. HI was also less than 1.
Conclusion: The value of HQ showed that inhalation of mercury vapor and ingestion were the main routes of exposure to Hg for children and adults. The non-carcinogenic risk was within the safe value (HI <1) in this study.
 

Trend of ambient air particulate matter with aerodynamic diameter of 2.5 μm and smaller in Zahedan city in 2018-2019
Hossein Kamani, Mohammad Sadegh Hassanvand, Abdolali Khammari, Sadegh Haghighat,
Volume 13, Issue 4 (2-2021)
Abstract
Background and Objective: Air pollution is one of the most important environmental risk factors that exposure to it can cause many acute and chronic effects on human health. Some regions of Iran, especially the western, southern and southeastern provinces of the country, have been affected with dust storm for years. Studies on the frequencies of dusty days in the country show that central pits of Iran and the cities of Zabol and Zahedan have the highest incidence of dusty days. The purpose of this study was to determine the concentration of suspended particles with aerodynamic diameter of 2.5 μm or less (PM2.5) in various seasons and months during 2019 in Zahedan.
Materials and Methods: In this descriptive-analytical and cross-sectional study samples were typically collected once every 6 days during a 24-hour period as well as on dusty days using an air sampler (PQ200 / BGI) from July 2018 to July 2019.
Results: The results show that the mean concentration of PM2.5 in Zahedan during this study was 36.86 µg/m3. The maximum and minimum PM2.5 daily concentrations in the sampling days were also measured as 130.8 and 4.75 µg/m3, respectively.
Conclusion: In conclusion, 88% of samples contained PM2.5 concentration above the WHO 24-hr air quality guideline level (25 µg/m3), which could be due to the high incidence of summer dust storms. This indicates that particulate matters are a serious health threat to people living in those areas and calls for the implementing measures to tackle the problem.

Page 1 from 1     

© 2024 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by: Yektaweb