faezeh borhani; Mohsen Mirmohammadi; Alireza Aslemand
Abstract
Back ground: Urbanization and development has always been led to air pollution. Volatile organic compounds such as benzene, toluene, ethylbenzene, and xylene (BTEX) are known as one of the most important groups of air pollutants. The present study aims to measureand investigate the outdoor concentrations ...
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Back ground: Urbanization and development has always been led to air pollution. Volatile organic compounds such as benzene, toluene, ethylbenzene, and xylene (BTEX) are known as one of the most important groups of air pollutants. The present study aims to measureand investigate the outdoor concentrations of BTEX in Tehran, Iran. Methods and Materials: The National Institute for Occupational Safety and Health (NIOSH)'s methods were applied to measure the concentrations of BTEX in winter and spring of 2015 at 46 stations as well as in July 2003 at 19 stations. Sample preparation and extraction were accomplished by CS2 solvent. Sample and data analysis were performed by Gas Chromathography (GC) and SPSS-16 software respectively. Results: In 2003, The BTEX pollutants were more observed in the eastern, central and southern zones of Tehran, respectively. The average concentrations of BTEX were 238, 130, 69 and 118 ppb, respectively. The benzene to toluene (B/T) ratios were between 0.8 to 3.2, which indicated the poor quality of gasoline. In 2015, the BTEX concentrations in District 19 (south of Tehran) were higher than eastern and central regions, which located in traffic zones with extensive development in public transportations. Conclusions: Improvement of gasoline quality, renewal of private cars and development of subway and public transportation till 2015 can be considered as the most important factors in decreasingBTEX concentrations to allowable amounts. During this year, thehe average concentrations of BTEX were 5.3 ppb, 9.2 ppb, 1.5 ppb and 2.6 ppb, respectively. The B/T ratio was fluctuated between 0.39 to 0.76, which depicted the remarkable role of vehicle traffic in BTEX pollution.
Ali Asghar Najafpoor; omid nemati sani; hosein alidadi; aliakbar dehghan; Saeed Azarmi Moheb Seraj
Abstract
Introduction: Ciprofloxacin is one of the most important synthetic antibiotics from the fluoroquinolone group and is widely used in medicine and veterinary medicine. The presence of fluorine atom in its composition has made stability and Sustainability. Recently, ozone is used for wastewater treatment, ...
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Introduction: Ciprofloxacin is one of the most important synthetic antibiotics from the fluoroquinolone group and is widely used in medicine and veterinary medicine. The presence of fluorine atom in its composition has made stability and Sustainability. Recently, ozone is used for wastewater treatment, odor control and removal of persistent organic compounds. Ozone acts through direct oxidation or the mechanisms of chain reactions that result in the release of hydroxyl radicals. Goal: The aim of this study was to determine the efficiency of ciprofloxacin removal by ozonation process from aqueous solutions. Material and methods: In this study, at first, concentrations of produced ozone of generator were determined by iodometric method. The studied parameters in the process includingciprofloxacin concentrations of 10-50 mg/L, pH of 3-12, a reaction time of 60 min and an ozone concentration of 1.4 mg/lit.min was investigated in a semiconductor reactor. The remained concentrations of ciprofloxacin in the samples were measured by HPLC. Results: In the optimal condition, at pH: 12, O3: 1.4 gr/lit.min, and initial antibiotic concentration of 10 mg/L, 94.6% of ciprofloxacin was removed. Conclusion: The results showed that ozonation can be a suitable method for removal of ciprofloxacin antibiotic from aqueous solutions.
reza shokoohi; Hossain Farji; Seyed Amir Ghiasian; Javad Faradmal; Salah Azizi; mahdi salari
Abstract
Background & Objective: Cadmium is considered as one of the most hazardous heavy metals, a non-essential, non-beneficial and highly toxic element to people. In the current study, the ability of aspergillus terreus fungi biomass was surveyed in the removal of cadmium from aquatic solutions. Materials ...
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Background & Objective: Cadmium is considered as one of the most hazardous heavy metals, a non-essential, non-beneficial and highly toxic element to people. In the current study, the ability of aspergillus terreus fungi biomass was surveyed in the removal of cadmium from aquatic solutions. Materials & Methods: This cross-sectional study was carried out in 2015 using fungal biomass culture on a shake flask. The dead biomass of aspergillus terreus fungi was applied as an adsorbent for the treatment of aquatic solution under the conditions of cadmium concentrations: 20, 40, 60, 80, 100 and 120 mg/l, pH: 3, 5, 7 and 9, retention time: 15, 30, 45, 60, 90, and 120 min and adsorbent dose: 0.1, 0.2, 0.5, 1 and 2 g. The remained concentrations of cadmium after adsorption were determined by atomic absorption spectrophotometer. Results: Results indicated that under condition of retention time: 90 min, pH: 7, initial cadmium concentration: 20mg/l and adsorbent dose: 1g, the biomass had a removal efficiency of 94%. Moreover, Adsorption process fitted to Freundlich isotherm with R2=0.9463 and first order kinetic with R2=0.9935. Conclusion: In current study, it was observed that the factors of pH, retention time, dose of aspergillus terreus fungi and initial cadmium concentration had a noticeable effect on the adsorption amount. with regard to the high adsorption capacity of the biomass in comparison to other adsorbents in the removal of cadmium, this biomass can be used as a good adsorbent in wastewater treatment.
abbas Khodabakhshi; Mohammad Rasoul Asadi Amirabadi; Morteza Sedehi; Kobra Shakeri
Abstract
Introduction: With the development of society and people's lifestyle changes/ the use of disposable containers has become inevitable. The use of these containers threatens public and personal health. At present/ Iran is among the 5 countries with the highest use of these containers in the world. ...
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Introduction: With the development of society and people's lifestyle changes/ the use of disposable containers has become inevitable. The use of these containers threatens public and personal health. At present/ Iran is among the 5 countries with the highest use of these containers in the world. This study is conducted to measure the concentrations of heavy metals including lead/ chromium and copper in disposable containers used in Shahrekord City. Method: For this purpose/ three disposable container samples including foam/ plant/ and plastic were provided from each company. The total number of collected samples was 72 samples were collected from three different companies.. The samples are extracted based on ISIRI standard and the concentrations of heavy metals were determined by atomic absorption spectroscopy. SPSS was used to statistically analyse the obtained data. Results: The mean concentrations of heavy metals in these containers for copper/ chromium and lead based on foam/ plant and plastic were (8.19/ 7.4/ 0.83- 4.5/ 6.04/ 3.33 and 3.73/ 7.09/ 0) based on the type of container glass/ food container and spoon (5.55/ 6.07/ 2.55- 5.26/ 7.48/ 2 and 4.32/ 6.75/ 0)/ and Iranian/ Ghaem and Kiyani in terms of brand (5.36/ 2.46/ 1.56- 5.68/ 10.76/ 1.68 and 4.35/ 7.1/ 1.12) per kg (mg / kg) of dry weight respectively. Conclusion: The comparison of the amount of metals in disposable containers showed that the average concentration of lead compared to the maximum recommended amount of lead (2 mg.kg) is within the standard limits. And the average concentration of chromium in disposable containers is higher than the maximum recommended amount (1 mg.kg). No certain standard is determined for copper.
Mahmoud Mohammadyan; milad pouransari; reza ali mohammadpour tahmtan; razie yousefinajad; shahram eslami
Abstract
Introduction: Exposure to respirable cement dust cause some adverse health effects on exposed workers. The aim of this study was to assess the risk of occupational exposure to respirable cement dust for a cement factory's workers and recommend controlling methods to reduce the risk of exposure. Materials ...
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Introduction: Exposure to respirable cement dust cause some adverse health effects on exposed workers. The aim of this study was to assess the risk of occupational exposure to respirable cement dust for a cement factory's workers and recommend controlling methods to reduce the risk of exposure. Materials and methods: The 0600 standard method of NIOSH was applied to evaluate workers' exposure to cement respirable particles using a personal sampling pump, a cyclone and a filter. For risk assessment of cement respirable particles, a standard method which provided by the Institute of the occupational health and Safety in Singapore was used. Finally, the risk level of exposure to respirable cement particles was assessed. Results: The results of this study showed that most workers employed in various worksites of the cement production were exposed to dust higher than the OEL recommended by the Technical Committee of occupational health in Iran, and the TLV recommended by ACGIH. Exposure risk assessment in different parts of cement factory showed a moderate risk level for all worksites. Conclusions: Employees who were working in different worksites of the plant were exposed to risk of cement respirable particles. Thus, the control methods of exposure to particles are suggested.
Mahmoud Mohammadyan; Ahmad Alizadeh Larimi; Mohsen Gorgani; Fatemeh Taghavi Soghondikolaei
Abstract
Background & objeftive: Electromagnetic field comprises electric and magnetic fields which is produced by electricity current. Long term exposures to electromagnetic fields have some adverse health effects on exposed workers. Applications of equipment which create electromagnetic field are increasingly ...
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Background & objeftive: Electromagnetic field comprises electric and magnetic fields which is produced by electricity current. Long term exposures to electromagnetic fields have some adverse health effects on exposed workers. Applications of equipment which create electromagnetic field are increasingly high. Therefore, the current study was carried out to evaluate electromagnetic fields in one of the oil product distribution company in Mazandaran province. Materials & Methods: In this cross-sectional study a real time EMF measurement device was used to evaluate electromagnetic field in the vicinity of computers’ monitors, cases, servers, copying machines, and also in electricity posts. Measurement was carried out in 28 sites and the results were compared with national and international standards. Results: The average of electric field for all stations was 44.4 v/m and the maximum and minimum rates of electric field were 208 and 0.5 v/m related to copying machine and the electricity generator respectively. The mean magnetic field density was 61.7×10-6 mT for all studied sites. The highest magnetic field intensity (5.0×10-4 mT) was found in high voltage fuse box and the lowest (0.2×10-6 mT) was related to electricity control room. Conclusion: The measured electric and magnetic intensity fields were lower than national and international standards. As the intensity of evaluated electric and magnetic fields were lower than national and international recommended levels, the workers would exposed to safe level of electromagnetic field.
Maryam Ghiasi; Hassan Narollahzadeh Saravi; Mohammad Binaii; Mahmod ghanei tehrani
Abstract
Introduction: Being free from human health risk factors is considered as the most important parameter of drinking water sources.The aim of the present study was quantative evaluation and identification of fungi in water of Shahid Rajaeii dam lake, and assessment of its health quality as drinking water ...
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Introduction: Being free from human health risk factors is considered as the most important parameter of drinking water sources.The aim of the present study was quantative evaluation and identification of fungi in water of Shahid Rajaeii dam lake, and assessment of its health quality as drinking water source of Sari (Mazandaran province). Materials and Methods: In the present study, samples were taken from five stations in six stages from June to February 2012. Every sample was diluted by sterile saline (100 and 10-1) and was cultured on SD and incubated at 27-30°C for 3-5 days. Finally, the number of colonies was recorded as Colony Forming Unit (CFU) per 100 mL. Also, teamperature, BOD5 and COD were measured. Results: The results showed that the numbers of isolated fungal colonies were significantly highest and lowest in August and February respectively. Moreover, the number of fungal colonies in the dam crown station was significantly higher than other stations. The correlation coefficient between the number of isolated colonies and the temperature, BOD5 and COD were 0.87, 0.60 and 0.66 respectively. The frequency of identified fungi were Aspergillus species (31.4%), various types of yeast (mainly Candida) (24.2%), Penicillium sp. (19.3%), Cladosporium sp.(10.3%), Mucor sp. (5.4%), Fusarium sp. (2.9%), sterile hype (2.8%), Alternaria sp. (2.3%) and Paecilomyces sp. (1.4%). Summery: The results showed the highest correlation coefficient between the counts of fungi and the changes in temperature, BOD5 and COD correspondingly. These factors play an important role in the fungal colonies counts. Moreover, the most fungal isolates were pathogenic, toxigenic and hazard to public health.