Pegah Nakhjirgan; Mohammad Hadi Dehghani
Abstract
Background and objective: Increased use of nanoparticles in industries leads to entering hazardous substances to environment. Nanoparticle toxicity due to release of toxic substances into the environment is a concern for communities. One of the common nanoparticles ingredients are zinc oxide. In this ...
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Background and objective: Increased use of nanoparticles in industries leads to entering hazardous substances to environment. Nanoparticle toxicity due to release of toxic substances into the environment is a concern for communities. One of the common nanoparticles ingredients are zinc oxide. In this study toxicity of the solution containing the Reactive Red 120 dye after Nano-catalytic process UV/ ZnO using biological test Daphnia magna was studied. Methods: this is a fundamental – practical study, which done on laboratory scale. Toxicity assay tests were carried out using Daphnia magna a bio-indicator. Then results of toxicity tests using SPSS software were analyzed and Lc50were determined. Results: Results showed that the Lc50 value at 24,48,72,96 hr is 73.16, 55.93, 41.32, 30.45 mg/l and the toxicity unit values are 1.36, 1.78, 2.42, and 3.28, respectively. Conclusion: the results generally indicated that toxicity increased in process and over time and showed that Reactive Red 120 after UV/ ZnO process was toxic to Daphnia magna. Paper Type: Research Article
Mohammad Reza Samarghandi; Ramin Khoshniyat; Ali Reza Rahmani; Ghodratollah Roshanaei; Ali Poormohammadi; Keyvan Saedpanah
Abstract
Introduction & Objective: Nowadays, the electronic devices are being used in our living environments and workplaces. The effect of magnetic fields from electronic devices on the microorganism has been taken into special consideration. The aim of this study was to examine the effect of magnetic fields ...
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Introduction & Objective: Nowadays, the electronic devices are being used in our living environments and workplaces. The effect of magnetic fields from electronic devices on the microorganism has been taken into special consideration. The aim of this study was to examine the effect of magnetic fields on the microorganism exiting in water. Material & Methods: In this study two solenoid with 250 standard coil connected to a power source were used. So, a magnetic field (intensity of 100,200 and 300 mT) was created. The effect of magnetic fields was investigated in laboratory condition on temperature, pH, turbidity, total coliforms, focal coliforms and heterotrophic bacteria plate count of water samples. Also the effect of the time passed (10,20,30,40 and 50 mintues) on the cases and control samples was surveyed. Results:Results showed that the use of magnetic fields cause a significant increase in MPN/100 ml, coliform, total coliform and heterotrophic bacteria plate count in experimental samples in comparison with the control samples. Also, in most samples, this increase was more effective in 100 mT. According to the results, a slight increase was observed in temperature, pH and turbidity of samples under the influence of applied magnetic field. Conclusion: The main results obtained in this study indicated that the magnetic fields lead to an increase inMPN/100 ml, coliform, total coliform and heterotrophic bacteria plate count. In contrast, the results did not confirm the effect of magnetic fields on temperature, pH and turbidity of the water solution.
Mohsen Yazdani; Ali Asghar Najafpoor; Ali Akbar Dehghan; Hossein Alidadi; mahmood dankoob; Reyhane Zangi; Sima Nourbakhsh; Reza Ataei; Ali Asghar Navaei fezabady
Abstract
Background and objectives: Tetracycline is known as the second high consumed groups of antibiotics throughout the world, which their entrance into the domestic wastewater will lead to pollute the water resources. The aim of this study was to determine the performance of combined Ultrasonic/UVprocess ...
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Background and objectives: Tetracycline is known as the second high consumed groups of antibiotics throughout the world, which their entrance into the domestic wastewater will lead to pollute the water resources. The aim of this study was to determine the performance of combined Ultrasonic/UVprocess in removal of tetracycline antibiotic from aqueous environments. Material and methods: This experimental study was performed by the ultrasonic bath associated with ultraviolet radiation. To determine the effects of independent variables including contact time (5-60 min), initial antibiotic concentration (5-25 mg/l), pH (3-10) and the input power (100- 300 W) on response variable (tetracycline removal), the samples were taken from reactor in different time intervals and the residual concentrations of tetracycline were measured by spectrophotometer in 261 nm wavelength. Results: The results of this study showed that the removal efficiency of UV and Ultrasonic processes was16% and 32% in optimum conditions, respectively. While in Ultrasonic /UV process, removal efficiency increased. The best removal efficiency (72%) was observed in pHof 4.5, antibiotic concentrationof10 mg/I, input power of240 W and contact timeof50 min. Conclusion: According to the obtained results, Ultrasonic/UVprocess can be used as an effective process to remove the tetracycline antibiotic from aqueous solutions.
Abolfazl Rahmani Sani; Ahmad Hosseini Bandehgharaei; Mahsa Naeemi; Ameneh Navidzadeh; Elham Agheli
Abstract
Background and aim:Antibiotics are a category of organic pollutants that can cause serious environmental problems through their disposal and uncontrolled release to the environment. The purpose of this study was to investigate the removal of sulfadimethoxine from aqueous solutions using carbon ...
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Background and aim:Antibiotics are a category of organic pollutants that can cause serious environmental problems through their disposal and uncontrolled release to the environment. The purpose of this study was to investigate the removal of sulfadimethoxine from aqueous solutions using carbon nanotubes.
Materials and Methods:The present work was an experimental study in which the effects of different parameters, such as PH, contact time, doses of carbon nanotubes, and different concentrations of sulfadimethoxine, on the removal of antibiotic from solutions were examined. All experiments were carried out in a 100-mL reactor at laboratory temperature (24 ± 2 ° C) using a magnetic stirrer at 350 rpm.
Results:The results showed that the maximum removal efficiency (94.5%) was occurred at pH = 6, adsorbent dosage 0.04 g, contact time of 30 min, and initial concentration of 20 mg/L. The findings on the effect of pH showed that the adsorption capacity increases with increasing pH, and at pH = 6, it reaches its maximum and then decreases again. The extent of removal was increased by increasing the dose of carbon nanotubes and the optimum amount for initial concentration of 100 mg/L (50 mL) was 0.04 g. The amount of absorption increased with increasing contact time and the maximum absorption occurred when the contact time was 30 min. The sulfadimethoxine antibiotic isotherm followed the Langmuir isotherm model (R2 = 0.9800) and the pseudo-second-order kinetic model (R2 = 0.9937).
Conclusion: The results showed that carbon nanotubes have a high potential for removal of sulfadimethoxine from aqueous solutions, due to its properties like its high surface area.
Maryam Hemmati; Arezoo Ghaemi; Haman Tavakkoli
Abstract
Introduction: Environmental problems caused by arrival of antibiotics in water resources due to toxicity and lasting effects are a serious threat. This study has been aimed to evaluate the efficiency of granular activated carbon as adsorbent for the removal of Cephalexin from aqueous solutions. Materials ...
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Introduction: Environmental problems caused by arrival of antibiotics in water resources due to toxicity and lasting effects are a serious threat. This study has been aimed to evaluate the efficiency of granular activated carbon as adsorbent for the removal of Cephalexin from aqueous solutions. Materials and Methods: This study was performed at laboratory scale and batch system. The influence of process variables such as pH of solution, adsorbent dosage, initial Cephalexin concentration and contact time were Investigated. Equilibrium study data were modeled using Langmuir, Freundlich and Temkin, moreover, kinetic studies were done by models of pseudo first order and pseudo second order. Findings: This research found that the Cephalexin adsorption efficiency decreased by increasing pH from 2 to 14, so that after 3 hours, the adsorption efficiency at the 20 mg.L-1 initial Cephalexin concentration and 0.2 g adsorbent, obtained 92.812%, 90.525% and 41.394% at pH 2, 3.5 and 14, respectively. The adsorption of Cephalexin was compatible with Langmuir isotherm and pseudo second order kinetic. Discussion and Conclusions: The present study showed that the granular activated carbon has high potential for adsorption and separation of Cephalexin and such pollutants from aqueous solutions, in addition to features like simple and rapid separation.
Ahmad Khosravi Baqdade; Taher Shahryari; Rasol Khosravi
Abstract
Background and purpose: Today, environmental pollution is a major problem for human life. Dye is one of the most important environment pollutants that is found in the industrial wastewater, especially in the textile industry wastewater. Therefore, the aim of this study was to evaluate the photocatalytic ...
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Background and purpose: Today, environmental pollution is a major problem for human life. Dye is one of the most important environment pollutants that is found in the industrial wastewater, especially in the textile industry wastewater. Therefore, the aim of this study was to evaluate the photocatalytic effect of green iron nanoparticles as catalyst for Reactive red 198 dye degradation in photocatalytic process. Materials and Methods: This study was performed laboratory using a batch reactor under UV A irradiation. In this study, the effect of different variables including pH (3-11), dye concentration (10-100 mg / l), catalyst dosage (0.25-3 g/l) and contact time (2-60 min) were investigated. The characterization of prepared nanoparticles were studied using different techniques such as TEM, FESEM and FTIR analysis. The obtained data were analyzed by Excel software. Results :Also, the photocatalytic tests showed high performance of NPs for dye degradation as catalyst in photocatalytic process. The highest removal efficiency achieved 96.2% at pH 3, catalyst dosage 1.5 g / L, contact time 15 min, and for dye concentration 25 mg / L. Conclusion :Additionally the results show that the photocatalytic process using green iron nanoparticles can be used with a suitable function to removal of reactive red 198 from aqueous solutions.
Edris Alang
Abstract
Plastics are widely used in society due to their many benefits, cheapness and availability and global plastic production in 2018 reached 359 million tons per year. The World Health Organization (WHO) identified the cause of Covid-19 virus in late December 2019 in Wuhan, China. During the pandemic of ...
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Plastics are widely used in society due to their many benefits, cheapness and availability and global plastic production in 2018 reached 359 million tons per year. The World Health Organization (WHO) identified the cause of Covid-19 virus in late December 2019 in Wuhan, China. During the pandemic of Covid-19 disease, the use of disposable face masks was recommended as the simplest solution to prevent the transmission of Covid-19. Unprecedented increase in the production and use of masks and gloves is a new environmental challenge that has led to an increase in plastic waste in marine habitats and environments. The World Health Organization estimates that approximately 89 million medical masks are required each month to respond to Covid-19. Improper disposal and disposal of these items has caused them to enter the coastal and marine environment through runoff as well as coastal visitors. Disposable face masks are plastic macro debris that can be broken into smaller pieces called microplastics and Ingestion by sea animals. Proper waste management, awareness and education of people about the proper disposal of these personal protective equipment items, use of washable masks, are strategies that can play an effective role in reducing the presence of this waste in the environment.
Akram Ghorbani; Farid Gholamreza Fahimi; Ahmad Tavana; Masood Kiadaliri; Mitra Mohammadi
Abstract
One of the complications of transportation in cities is noise pollution caused by vehicles. Today, noise in urban environments is an important issue in the field of public health. Due to the negative effects of noise pollution on human health and well-being, it is necessary to identify and understand ...
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One of the complications of transportation in cities is noise pollution caused by vehicles. Today, noise in urban environments is an important issue in the field of public health. Due to the negative effects of noise pollution on human health and well-being, it is necessary to identify and understand these effects on the health of exposed people. In this study, the type of traffic axis composition of the highway was identified and the type of traffic information required was identified by identifying the locations for the sound station along the highway axis and preparing sound data and identifying the factors affecting sound propagation. At each sampling station, the required variables in the intervals of 7: 30-9: 30, 12: 30-14: 30, 18: 30-20: 30, 23: 30-1: 30 And 3: 30-5: 30 and different seasons of the year were measured and recorded for modeling. The results show that the comparison of the average parameters of noise pollution in different stations of Shahid Kalantari Highway at a significant level of 5% showed that the highest amount of noise and sound indicators measured are related to the first station of Abadgaran with the amount of deci, respectively. Bell is 79.61 dB, the entrance road to Kuhsangi is about 80 dB and the lowest station of Hafez Square is about 58 dB. The parameters Lmax, Leq, L10, L50 and L90 are visually uniform distribution of results in the fit line range. According to the results of this study, it is announced that in all seasons of the year, the average equivalent sound level in all stations studied is higher than the recommended daily ambient sound level in the Iranian open air sound standard. While the standard sound level in residential areas is 55 decibels during the day and 45 decibels at night.
Mohsen Mehdipoor; Mohammad Hadi Dehghani; Simin Nasseri; Kazem Nadafi; Amir Hossein Mahvi
Abstract
Background and objective: One of the industries producing environmental pollutant is the rubber industry, which has a lot of in environmental dangers. This study was conducted in the purpose of investigation on Ozone and coagulant material’s (Aluminum sulfate –Ferric chloride) efficiency ...
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Background and objective: One of the industries producing environmental pollutant is the rubber industry, which has a lot of in environmental dangers. This study was conducted in the purpose of investigation on Ozone and coagulant material’s (Aluminum sulfate –Ferric chloride) efficiency in waste water treatmentof Rubber Industry. Materials and Method: In this work Rubber industries with the industrial waste volume over 2500 m3 per mount was studied. In order to qualitative evaluation of wastewater in this industry, the reduction of turbidity and the amount of COD were considered as the qualitative criteria. Results: In this study, the reduction rate of COD by chemical treatment with Ferric chloride after ozonation was 34 percent and the wastewater of chemical treatment with aluminum sulfate after ozonation shown 48 percent, the reduction of COD. Conclusion: One of the scientific and practical approaches for the treatment of wastewater in these industries is the use of complex process like chemical coagulation and ozonation along with possible biological processes. Paper type: Research article
Parisa Dadkhah; Atefeh Chamani; Samar Mortazavi
Abstract
Background and aim:With the development of coastal industries and cities, aquatic ecosystems and organisms are exposed to contaminants, especially heavy metals. Heavy metals accumulate in aquatic tissues and eventually enter the food chain and human body. The aim of this study was to investigate the ...
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Background and aim:With the development of coastal industries and cities, aquatic ecosystems and organisms are exposed to contaminants, especially heavy metals. Heavy metals accumulate in aquatic tissues and eventually enter the food chain and human body. The aim of this study was to investigate the concentrations of lead, cadmium and zinc in muscle of two fish species (Cicharhinuslimbatus) and (Epinepheluscoioides) from the Persian Gulf.
Materials and Methods:For this purpose, 15 samples of muscle were takenfrom each fish, and by wet digestion method, the concentration of Lead, Cadmium and Zinc were measured by atomic absorption device. Statistical analysis of the obtained results was carried out by SPSS software (v.20) using Shapiro-Wilk, One Sample T-Test and Binomial Test.
Results:According to the results, the mean concentrations of lead, zinc and cadmium were 5.55, 8.40, 0.22 mg/kg and 9.14, 13.54, 0.27 mg/kg, in Cicharhinuslimbatus and Epinepheluscoioides respectively. The mean concentration of lead in both fisheswashigher than the WHO standard. The HI index for Cicharhinuslimbatus and Epinepheluscoioides is less than 1.
Conclusion: With respect to the obtained results, the absorption of these metals does not threaten consumers. However, the proportions of condition factor for Cicharhinuslimbatus and Epinepheluscoioides are not within the standard range and indicate the inappropriate conditions of this habitat for aquatic health and environmental stresses.
Farshad Golbabei Kootenaei; Nasser Mehrdadi; Gholamreza Nabi Bidhendi; Hasan Aminirad; Mahdi Asadi Ghalhari; Farima Saeedi
Abstract
Abstract Background and purpose: Reducing the amount of sludge produced by the biological treatment of active sludge is of great importance. The main task of dewatering unit is to separate water from excess sludge. The aim of this study is to determine the effect of ultrasonic waves on coagulants in ...
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Abstract Background and purpose: Reducing the amount of sludge produced by the biological treatment of active sludge is of great importance. The main task of dewatering unit is to separate water from excess sludge. The aim of this study is to determine the effect of ultrasonic waves on coagulants in improving the sludge dewatering process and increasing solid content of sludge cake. Materials and methods:This is an experimental study performed in batch laboratory scale. During the two seasons, 12 samples were taken at 15 days’ intervals. Variables include ultrasound density (0.375, 0.75, 1, 1.3 and 2.5) in watts per ml, Time (1, 5, 10, 15 and 30) in minute, and specific energy input (208, 1041, 2083, 3124 and 6249) in kilojoule on kilo total suspended solids. The effects of ultrasonic waves on coagulants were investigated by using Particle Size Analizer (PSA). Results:The optimum amount of solid content of sludge and capillary suction time (CST) was equal to 26.4 percent and 86 seconds in sonification time of 5 minutes and specific energy input of 1041 kj/kg TS. By applying ultrasonic waves, d10, d50, d90 and average particle size amount were equal to 6.3, 44.2, 24.4 and 28.84 micrometers respectively. Conclusion:Ultrasound waves create pores in the physical structure of the polymers and the increase of cationic surface charge increases the adsorption of particles and made larger flocs and can increase the solid content of sludge and improve sludge dewatering process.
Mitra Gholami; Mojtaba Davoudi; Simin Naseri; Amir Hossein Mahvi; Mehdi Farzadkia; Ali Esrafili; Hossein Alidadi
Abstract
Backgrounds & Objectives: Elimination of phenolic compounds which is considered as resistant pollutants to biological degradation has a great importance. This study aims to investigate the electrochemical oxidation process efficiency in removal of phenol compounds using a continuous and divided rector. ...
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Backgrounds & Objectives: Elimination of phenolic compounds which is considered as resistant pollutants to biological degradation has a great importance. This study aims to investigate the electrochemical oxidation process efficiency in removal of phenol compounds using a continuous and divided rector. Materials & Methods: The catalytic anodes of Ti/SnO2-Sb and cathodes of iron were employed in a reactor divided into anolyte and catholyte chambers by a cellulosic separator. The influence of initial phenol concentration (14.12‒40.88 mg L‒1), retention time (32.23‒82.77 min), and current intensity (0.18‒0.42 A) on TPh removal efficiency, TPh residual concentration, and energy consumption was investigated using response surface methodology. Results: The results showed that TPh removal efficiency strongly depends on retention time, followed by current intensity and initial phenol concentration. The importance order of factors affecting on TPh residual concentration were distinguished as initial TPh concentration > retention time > current intensity. The energy consumption in terms of kWh m‒3 is mostly affected by retention time and then current intensity, and irrespective of initial phenol concentration. Under the optimal conditions, removal efficiency of 93.21%, residual concentration of 1 mg L‒1, and energy consumption of 34.40 kWh m‒3 is achieved. Conclusion: Based on the obtained results, the electro-oxidation is a very efficient process for diminution of wastewater phenolic content, and is able to set the allowable limits to discharge to the environment.
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.
Ahmad Alah Abadi; Aalieh Tabasi; Ayyob Rastegar; Ali Akbar Rodbari; Amin Masoodi
Abstract
Abstract Background and purpose: The presence of drugs in water and wastewater sources poses risks to humans and the environment. These materials are not completely eliminated by conventional water and wastewater treatment methods. This study aimed to investigate the photocatalytic removal of acetaminophen ...
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Abstract Background and purpose: The presence of drugs in water and wastewater sources poses risks to humans and the environment. These materials are not completely eliminated by conventional water and wastewater treatment methods. This study aimed to investigate the photocatalytic removal of acetaminophen from aqueous solutions by the advanced UV/H2O2/ZnO oxidation method. Materials and Methods: In this experimental analytical study, zinc oxide and hydrogen peroxide were used in a 500 ml reactor under UV-C irradiation to remove acetaminophen. The effects of initial parameters of acetaminophen, solution pH, contact time, hydrogen peroxide concentration, and zinc oxide nanoparticle concentration were investigated. Experiments were designed and analyzed using the CCD method by Design Expert 10 software. Results:Themaximum removal efficiency of acetaminophen was obtained as 94% at pH 7, contact time 8 min, the initial contaminant concentration 62.5 mg/l, catalyst dose 0.0275 g, and H2O2 concentration 2 ml. By changing the time to 1 and 15 minutes, the removal rate decreased by 26 and 76%, respectively, and by increasing the catalyst dose from 0.0275 g to 0.05 g, the removal rate increased by 99%. Conclusion:In this study, the efficiency decreased with increasing contaminant concentration. The removal efficiency was higher in neutral conditions than in acidic and alkaline conditions. The photocatalytic process (UV/H2O2/ZnO) is highly potent for removing acetaminophen from aqueous solutions.
Ghasem Ranjbar; Ali Asghar Najafpoor; Ali Akbar Dehghan
Abstract
Background and Objective: The main and most important way for heavy metals to enter human body is eating food. Given that vegetables are among main food sources. For this purpose, in this study heavy metals concentrations (lead, cadmium, Arsenic and mercury) in water and wastewater used, soil and vegetables ...
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Background and Objective: The main and most important way for heavy metals to enter human body is eating food. Given that vegetables are among main food sources. For this purpose, in this study heavy metals concentrations (lead, cadmium, Arsenic and mercury) in water and wastewater used, soil and vegetables of Kashafrood margin River farms are investigated. Materials and Methods: In this in vitro study, 54 samples of three vegetable types and 18 water and wastewater samples and 18 soil samples were taken from three farms (one control and two case farms) in two consecutive months. The case farms were selected in Kashafrood River vicinity, where flow treatment plants municipal sewage and wastewater in Mashhad city. After preparation, samples acid digestion action was performed according to standard methods (3030 F Standard Method for water and vegetables – 3050 B EPA for soil). Atomic absorption device (spectrometry) was used to determine the concentration of heavy metals in samples and SPSS and Excel software were used to analyze the data. Finally, the information obtained was compared with national and international standards. Results: The mean concentrations of heavy metals (lead, cadmium, arsenic and mercury) in water, soil and vegetable samples were different and varied in time and place. Among the selected vegetables, dill samples, among farms, farm 2 and among months June illustrated most polluted one, and of the heavy metals in the samples, lead had highest concentrations. Conclusion: Heavy metal concentrations in soil and water samples were within national and international standard range, while concentrations of these metals in some vegetable samples exceeded national and international levels, which may be due to other factors, however, the use of standard effluent for agricultural irrigation requires control measures and the performance of relevant machinery duties. Keywords: Vegetables, Kashafrood, Heavy Metals
Reza Zahedi; Hossein Ghafourian; Yahya Zamani; Shahrzad Khoramnejhadian; Reza Dabbagh
Abstract
Background and purpose: The carbon monoxide is an important compound which can convert to different chemical materials which is harmful to environment and humans. Selecting the mechanism and absorbent to absorption pollutant gases is very important due to the efficiency. This study aimed to optimize ...
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Background and purpose: The carbon monoxide is an important compound which can convert to different chemical materials which is harmful to environment and humans. Selecting the mechanism and absorbent to absorption pollutant gases is very important due to the efficiency. This study aimed to optimize the carbon molecular sieves prepared which cause the adsorption of more carbon monoxide.Materials and methods: In this study, a walnut shell was used to prepare a carbon molecular sieve and activate the carbon was used physical method. The adsorbents were optimized during two modifying and coating processes after granulation. The adsorbents were modified at pH = 4.5-6.5-9 which layered with oil-oil and oil-thinner mixtures (1: 1 ratio). The adsorption capacity of carbon monoxide by the adsorbents was measured by the volumetric method under the same conditions (2g of adsorbent, 25 °C temperature, and 2 bar pressure).Results: The highest efficiency among those without modified adsorbents for CMS (Ac) with 0.281 mmol CO/g adsorbents and among those coated with oil-kerosene adsorbents for CMS (Al-K) with 0/591 mmol CO/g adsorbent and among the adsorbents coated with oil -thinner and among all adsorbents for CMS (Al-T) with 0.858 mmol CO/g adsorbents.Conclusion: A carbon molecular sieve can absorb and reduce the concentration of CO, which is an environmental pollutant. Optimization causes to increase the adsorption efficiency.
Farshid Kafilzadeh; Zeinab Khaledi
Abstract
Background & Objective: Bioaugmentation is a great technique in bioremediation of contaminated soils with petroleum hydrocarbons. The aim of this study was to evaluate the effect of isolated bacteria from activated sludge as non-indigenous bacteria in bioremediation of kerosene contaminated soils ...
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Background & Objective: Bioaugmentation is a great technique in bioremediation of contaminated soils with petroleum hydrocarbons. The aim of this study was to evaluate the effect of isolated bacteria from activated sludge as non-indigenous bacteria in bioremediation of kerosene contaminated soils and study the growth of isolated bacteria in the presence of different concentrations of this product. Materials & Methods: Sampling of activated sludge was taken from two treatment plants in Assaluyeh region. Isolation of degrading bacteria was performed by culturing the samples on basal mineral medium. Emulsification test and evaluating growth of bacteria were carried out in different concentrations of kerosene. Isolated bacteria were inoculated to polluted soils with kerosene oil compound for bioaugmentation. The evaluation of their bioremediationpotentialand the rate of biodegradation were measured by infrared spectroscopy (IR). Results: In this study, two bacteria Pseudomonas putida and Serratia marcescens were isolated and identified as kerosene degrading bacteria from activated sludge. P. putida was recognized as the most powerful degrading bacterium of this oil product according to emulsification tests, measuring the growth of bacteria in various concentrations of kerosene, the results of Bioaugmentation of contaminated column of soil with kerosene and reduce the level of TPHs. Conclusion: In regard to adaptation of activated sludge bacteria with variety of pollutants in sewage, they can be used as non-indigenous bacteria for bioaugmentation and cleaning up contaminated soil with petroleum hydrocarbons.
Khosrow Ashrafi; Mehdi Fattehi; Mohamad Pootehrigi
Abstract
Background and Purpose:In recent years, the use of Bus Rapid Transit in Tehran has been taken into consideration and largely follows the satisfaction of the citizens of Tehran. Bus Rapid Transit (BRT) system reduce transport costs, increase speed and, ultimately, the comfort of the public. ...
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Background and Purpose:In recent years, the use of Bus Rapid Transit in Tehran has been taken into consideration and largely follows the satisfaction of the citizens of Tehran. Bus Rapid Transit (BRT) system reduce transport costs, increase speed and, ultimately, the comfort of the public. Therefore, in this research, the impact of the performance of BRT system is discussed. Materials and methods:In order to achieve this goal, first, the traffic volume of vehicles in two scenarios by existence and nonexistence of BRT were obtained by the model; Eventually, after calculating the driving pattern by measuring in the field, estimating the fuel quality and calculating the type of fleet of the path, the amount of emissions of pollutants produced by each vehicle were obtained based on the model International Vehicle Emissions (IVE); and Eventually, the pollutants emissions from moving sources were compared in these two scenarios to achieve the effectiveness of the using BRT system. Results: According to the results obtained from the route, the existence of BRT reduced carbon monoxide by 134.92 kg, volatile organic compounds by 5.13 kg, benzene by 0.48 kg, carbon dioxide by 4631.97 kg, nitric oxide by 0.37 kg and methane emissions by 6.86 kilograms. But it increased particles of less than 10 microns by 0.48 kg, nitrogen oxide by 0.8 kg and sulfur oxide emissions by 0.97 kg. Conclusion: According to the obtained results, the driving pattern and the traffic volume are two important variables in the IVE. The emissions of carbon monoxide and contaminants of volatile organic compounds are released majority from light cars. At the end, the presence of BRT leads to a significant reduction in carbon dioxide emissions, which is the main source of greenhouse gas emissions.
Fahimeh Khadempour; Ali Shahidi
Abstract
Introduction: Qualitative assessment of water resources using qualitative indicators as one of the most suitable methods for managing water areas and having a regular program for water quality protection and pollution prevention is necessary. Subject & method: The use of the CWQI index to identify ...
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Introduction: Qualitative assessment of water resources using qualitative indicators as one of the most suitable methods for managing water areas and having a regular program for water quality protection and pollution prevention is necessary. Subject & method: The use of the CWQI index to identify the country's water resources (especially lakes and rivers) can be a good tool. In this study, water quality was evaluated in two ophthalmic stations of Oliyakhonic and Farokhi in the Gain river basin of southern Khorasan province during the years of 2007-2016 with the use of this indicator and Aquachem software. In this study, parameters of calcium, magnesium, potassium, sodium, chloride, sulfate, electrical conductivity and acidity were used. Results: The CWQI index for agricultural consumption has been decreasing from the upstream downstream, which may be due to increased water salinity in the downstream direction or the flow of agricultural, industrial and urban wastewater (household and industrial waste). The level of pollution and the concentration of undesirable factors rises from the upstream and downstream, and undesirable water quality for fish life, so that most stations require purification for aquaculture. Conclusion: Both stations are in bad rank for drinking, aquatic, irrigation and livestock. Also, for both recreation both stations were in high rank. Also, according to the Piper diagram, the type and the water facies are bicarbonate-magnesium-calcium.
Samira Rahnama; Ali Shahidi
Abstract
Abstract Background and purpose: Surface water, especially rivers, are one of the most important water resources that play an important role to supply water requirements of different activities. and we able to make decisions about their application with their quality monitoring. This study was done to ...
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Abstract Background and purpose: Surface water, especially rivers, are one of the most important water resources that play an important role to supply water requirements of different activities. and we able to make decisions about their application with their quality monitoring. This study was done to evaluate the southern branches of Haleil Rood River quality using Canadian Water Quality Index (CWQI) and Aquachem software. Materials and Methods: In this cross sectional study, water quality parameters were used in three stations in the southern shaft of the Haleil Rood river (Hossein-Abad, Konarueyeh and Kahang-Sheibani) from 1996 to 2016. To determine the water quality of the river and determine the type and characteristics was used of the water quality index CWQI and Aquachem software Results: The results showed that water qualitative conditions in the two stations of Konarueyeh and Kahang-Sheibani are in high rank in different types of use. Hossein-Abad Station is in good condition for drinking and in terms of aquaculture in the border range and rank high for recreational activities, irrigation and livestock. Also, the analysis of the graphs obtained from Aquachem software showed that the river water of the Hossein-Abad station was in good order and the two another stations are in excellent condition. Conclusion: The cross sectional study of the chemical quality of the Haleil Rood river shows that the water river from the upstream to downstream is in excellent condition for drinking water. For agriculture, it is also within the range of high quality water. Based on the Piper diagram, the chemical quality of the river water is at the three stations studied, Sodium-Chloride. In addition based on the results, it is expected to be provided valuable information in connection with the use of water bodies by the local people of the study region.
Naser Rahimi; Masoud hamerezaee
Abstract
Background & Aims: Rivers are one of the most important water resources that play an important role to supply water requirements of different activities. and we able to make decisions about their application with their quality monitoring. This study was done to evaluate the right branch of ...
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Background & Aims: Rivers are one of the most important water resources that play an important role to supply water requirements of different activities. and we able to make decisions about their application with their quality monitoring. This study was done to evaluate the right branch of Sarugh River quality using National Sanitation Foundation developed the Water Quality Index (NSFWQI) and zoning obtained by geographic information system (GIS). Materials & Methods:In this cross sectional study, standard field parameters including dissolved oxygen, temperature, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand, Most Probable Number of Coliforms, Fecal Coliform, Turbidity, Total Dissolved Solids, Total Solids, pH, Conductivity and others were measured at five different stations of right branch of Sarugh Tekab during the spring and summer in 2016. Sampling points were selected based on their importance. Water quality index was calculated using water quality index calculator based on National Sanitation Foundation (NSF) information system. Results:The highest value of NSFWQI of the samples was 85 in A station in April while the lowest value was 55 in E station in May. Based on NSFWQI categories, water quality in A station was found in good category, and in other stations, were found within Moderate. Decreasing value of Water Quality Index (WQI) may be attributed to the high values of BOD and Fecal Coliform number in the stations of water. Conclusion:Study results showed good water quality for A station that is suitable for various applications. In addition based on the results, it is expected to be provided valuable information in connection with the use of water bodies by the local people of the study region.
Maryam Charmzan; Reza Esmaili; Mitra Mohammadi; Vahid Moradnezadhesare
Abstract
AbstractBackground and Aim:Air pollution is one of the most important environmental problems in the last century that threatens human health and particulate matter is one of the deadliest types of air pollution.This study was done to choose the best interpolation algorithm in the spatial distribution ...
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AbstractBackground and Aim:Air pollution is one of the most important environmental problems in the last century that threatens human health and particulate matter is one of the deadliest types of air pollution.This study was done to choose the best interpolation algorithm in the spatial distribution of PM2.5 suspended particles in Mashhad in 1395by different spatial models.Material and Methods: PM2.5 particulate concentrations was collected from 21 active air quality measuring stations in different parts of Mashhad and IDW, Ordinary Kriging (OK) and Universal Kriging (UK) interpolation models were evaluated to spatially investigate the air pollution situation in Mashhad. The root mean square error (RMSE) was used to compare the models and select the best model, and the Standardized RMSE was used to choose the most optimal conditions for running the OK and UK models.Results: The results showed that the highest seasonal average of PM2.5 pollutants in 1395 was related to autumn (40.84 µg/m3) and the lowest was related to spring (27.78 µg/m3). Also, the east to north area of Mashhad is in a more unfavorable situation in pollution concentration than the western areas of the city. Comparison of models using RMSE index also showed that OK model due to having the lowest amount of RMSE for seasonal average and annual concentration of suspended particles PM2.5 has a lower error in the predicted values than the measurement, so it has better conditions for intermediation.Conclusion: This research eventually led to the production of maps of PM2.5 Pollutants situation in the whole city of Mashhad, which is very useful in order to identify high-risk areas in the city and use useful measures to reduce air pollution in those areas.
Morad Ali Zareipour; Mohammad Saeed Jadgal
Abstract
The workplace, as a place where employees spend long hours and possibly interact with many people, is one of the most susceptible environments for transmitting the corona virus, so to minimize the risk of contracting the virus, adhere to health protocols in these environments. It is very important. Due ...
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The workplace, as a place where employees spend long hours and possibly interact with many people, is one of the most susceptible environments for transmitting the corona virus, so to minimize the risk of contracting the virus, adhere to health protocols in these environments. It is very important. Due to the lack of environmental health forces, the size of the departments, inspection and sensitization training of employees of all departments regarding the observance of coronavirus prevention protocols is not possible. Therefore, the authors in this article suggested the ambassadors of office health as participants in the health of the organization. A health ambassador is an employee of the organization who is the liaison between the health system and the employees of that organization. After receiving face-to-face and face-to-face training on coronavirus prevention health protocols by environmental health experts, the organization's health ambassador can carry out coronation prevention and control activities in their organization. The present study identified the importance of empowering health ambassadors of organizations as selected organizations to prevent coronavirus disease, will interrupt the transmission of coronavirus disease chain in employees.
Saeed Akbari; Mohammad Hadi Dehghani; Mehdi Salari
Abstract
Background and objective: Due to its high concentration on the surface and its pathogenic function, fluoride is noticeable. Fluoride at high concentrations can be dangerous. The World Health Organization's allowable concentration is 1.5milligrams per liter. The aim of this study was to take chitosan ...
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Background and objective: Due to its high concentration on the surface and its pathogenic function, fluoride is noticeable. Fluoride at high concentrations can be dangerous. The World Health Organization's allowable concentration is 1.5milligrams per liter. The aim of this study was to take chitosan from shrimp shells and evaluate its performance in the removal of fluoride in aqueous solutions. The purpose of this study was to isolate chitosan from shrimp shells native Persian Gulf and evaluate its performance in the removal of fluoride in aqueous solutions. Materials & Methods: Chitosan from shells native Persian Gulf shrimps in three stages, protein , minerals and de-acetylation separation. The isotherms and adsorption kinetics were evaluated in optimal conditions. Results: The results showed with 100 ml of 4 Results: milligrams per liter of fluoride, the fluoride removal at pH = 7, 60 minutes contact time and adsorbent concentration of 2 grams per liter respectively. The result of the absorption curve obeys a second-order. Freundlich adsorption isotherm data were more consistent. Maximum capacities of 0.157 milligrams per gram was with the removal of fluoride with chitosan. Conclusion:The extracted chitosan can be an effective adsorbent for the removal of fluoride from contaminated water so that the amount of fluoride in drinking water is reduced to below the allowable level of fluoride.
leila haddadi; reza marandi; nooshin sadjadi
Abstract
Background& Objective: One of the reuses of wastewater in industries is irrigation of green space. Therefore, with proper treatment and reduction of environmental pollution of wastewater and in compliance with environmental standards, it can be used for irrigation purposes. The present study was ...
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Background& Objective: One of the reuses of wastewater in industries is irrigation of green space. Therefore, with proper treatment and reduction of environmental pollution of wastewater and in compliance with environmental standards, it can be used for irrigation purposes. The present study was aimed to evaluate the performance of Noosh Azar Wastewater Treatment Plant by the online monitoring station in 2016. Materials and Methods: This descriptive cross-sectional study was performed at Noosh Azar Waste Water Treatment Plant (WWTP) in Tehran. The effluent outlet parameters include COD, BOD, TSS, TOC, Turbidity, pH and temperature which were measured 12 times/day by the online monitoring station of the refinery according to the standard methods (the Examinations of Water and Wastewater), and reported at the end of each month. Data were entered into SPSS software and analyzed using statistical indices including mean and standard deviation. Results: The average total of BOD/COD ratio in the wastewater was 0.8. The results of the study showed that the average concentration of COD, BOD and TSS of the wastewater was 1624.91 ±134.85, 1310±75.38 and 283.58± 39.76 mg/L, respectively. The average of total outlet parameters of turbidity, COD, BOD, TSS and TOC were 12.78±2.21, 83.73±12.90, 41.26±6.65, 6.70±2.14, 46.03±7.08 mg/L, and pH=7.80±0.35. The total average of removal efficiencies of COD, BOD and TSS were 93.92±3.62, 96.57±1.002 and 97.57±0.936, respectively. Conclusion: Regarding the proper performance of the activated sludge system of Noosh Azar Company, the effluent parameters such as COD, BOD, TSS, TOC, turbidity and pH, were in accordance with the standard of the Iranian Environmental Protection Agency for irrigation use. However in order to ensure the quality of the wastewater for reuse, the microbial parameters should also be considered.