Nafiseh Sarabi Mohajer; Maryam Sarkhosh; Ali Asghar Najafpoor; Hossain Alidadi; Sima Baridkazemi
Abstract
Background and Purpose: Consumers often think that food is safe whenstored in refrigerators at 4°C. However, food can still spoil and causefoodborne illness, which is one of the most important health challenges.The present study was conducted with the aim of investigating bacterial andfungal contamination ...
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Background and Purpose: Consumers often think that food is safe whenstored in refrigerators at 4°C. However, food can still spoil and causefoodborne illness, which is one of the most important health challenges.The present study was conducted with the aim of investigating bacterial andfungal contamination in domestic refrigerators.Materials and Methods: In this study, 30 domestic refrigerators wereexamined. First, microbial plates including blood agar and Saburo were placedon the refrigerator shelves for one hour. Then the bacterial cultures wereincubated for 48 hours at 36°C and the fungal cultures were incubated for 5days at 28°C and the colonies were counted. Finally, in order to check the levelof contamination of the refrigerator surfaces, treated samples were preparedfrom the surface of the refrigerator shelves using moist sterile swabs.Results: Based on the results, 100% bacterial contamination and 58% fungalcontamination were observed in the air of household refrigerators, and theamount of bacterial and fungal contamination on the surface of domesticrefrigerators was 4.7-8.9 and 3.6-7.2 (log CFU/cm2) respectivelyConclusion: As seen in this study, bacteria enter food through unwashedhands, raw foods, leaking packaging, unwashed shelves, refrigerator surfaces,and long-term storage of food in the refrigerator. Therefore, if refrigeratorsare not maintained properly, they become a place for the growth ofmicroorganisms and directly and indirectly contaminate the refrigerator andfood and make people sick
Mohammad Javad Chaboki; Ali Asghar Najafpoor; Ziaeddin Bonyadi; Ali Akbar Dehghan
Abstract
Background:Human activities, especially in construction and agriculture, introduce large amounts of nitrogen, phosphorus and organic matter into aquatic ecosystems. Method: In this study, municipal and industrial wastewater samples were obtained from wastewater treatment plant No. 1 of Parkand Abad and ...
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Background:Human activities, especially in construction and agriculture, introduce large amounts of nitrogen, phosphorus and organic matter into aquatic ecosystems. Method: In this study, municipal and industrial wastewater samples were obtained from wastewater treatment plant No. 1 of Parkand Abad and wastewater treatment plant of Kalat industrial park, respectively. Before starting the reactor, wastewater samples were allowed to settle for 2 h to remove coarse suspended solids and then sterilizes in autoclave. Chlorella vulgaris was purchased from Jahad Daneshgahi of Mashhad and grown in specific culture media under temperature 25±2°C, photoperiod of 14 h light and 10 h dark, monochrome light with intensity of 5000±350 lux, pH of 7-8.5 and time of 10 d. Then 1 L of the above solution were transferred to three 10 L reactors loaded with municipal, industrial and culture media and aerated under sterile conditions in the presence of light for 10 d. In predetermined time intervals (each 2 d), 100 mL sample were taken from reactors and COD, total phosphorous, total nitrogen, pH and chlorophyll a measured. Results: Removal efficiency of COD, total nitrogen, and phosphorus in municipal, industrial and culture media by Chlorella vulgaris was 63.69, 12.52, and 13.79%, 66.57, 34, and 50.18%, respectively. According to results, the efficacy of algae for removal of COD was higher than other parameters, while that for total nitrogen was lowest. Efficacy of algae for removing pollutants from industrial was better than those in domestic wastewater.Conclusion:The results of this study showed that municipal and industrial media could be a suitable culture media for growing Chlorella vulgaris algae. It also has the ability to remove nutrients from wastewaters.
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
Maryam Sarkhosh; Ali Asghar Najafpoor; Mona Tabriziazad
Abstract
Treatment of Fresh Leachate From Municipal Solid Waste This study aimed at the examination of the efficiency of roughing filter in nitrate and chemical oxygen demand removal (COD), obtained in the fresh leachate from municipal solid waste landfill. Sampling was done in 3 rates 0.5m/h, 1m/h and 1.5 m/h, ...
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Treatment of Fresh Leachate From Municipal Solid Waste This study aimed at the examination of the efficiency of roughing filter in nitrate and chemical oxygen demand removal (COD), obtained in the fresh leachate from municipal solid waste landfill. Sampling was done in 3 rates 0.5m/h, 1m/h and 1.5 m/h, including simultaneous sampling from input and output filtering, to determine the concentration of nitrate and COD. The average efficiency of COD removal in filtration rates of 0.5 m/h, 1 m/h and 1.5 m/h was equal to 84, 88 and 85 % respectively. The average removal efficiency of nitrate in filtration rates of 0.5 m/h, 1 m/h and 1.5 m/h was equal to 88, 88 and 85 % respectively. Output values of COD and nitrate were lower than the environmental organization standard (p < 0.05). Based on the results of this study, the nitrate removal with a roughing filter was better than that obtained with COD. Keywords: Roughing Filter, Nitrate, Chemical Oxygen Demand,
HOSEIN ALIDADI; Ali Asghar Najafpoor; somayeh etemadi mashhadi; Batoul Mohebrad; aliakbar dehghan
Abstract
Introduction: Waste leachate contains hazardous organic compounds such as nitrogen compounds and high concentrations of poisonous compounds; the remediation of these pollutants from the environment is considered as a global problem. These pollutants make serious environmental problems through their penetration ...
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Introduction: Waste leachate contains hazardous organic compounds such as nitrogen compounds and high concentrations of poisonous compounds; the remediation of these pollutants from the environment is considered as a global problem. These pollutants make serious environmental problems through their penetration into groundwater and bioaccumulation. Therefore, leachate treatment is essential with suitable and appropriate methods. Anaerobic digestion is considered as one of the most cost-effective methods for this mean. This study aimed to evaluate the efficiency of an anaerobic digester in simultaneous removal of chemical oxygen demand (COD) and TKN from landfill leachate during the process of anaerobic co-digestion for landfill leachate and fresh cow dung. Materials and Methods: In this study, landfill leachate of Mashhad and cow dung was mixed in 3/1, 1/1 and 1/3 ratios. These treatments were exposed under anaerobic digestion with same conditions such as environmental temperature. COD and TKN were measured at the beginning and the end of the process. Results: In the control treatment, COD decreased about 5% and the reduction of TKN was 9.09%. Whilst COD reduction was about 65%, 75%, and 70% in the treatments of 3/1, 1/1 and 1/3 Ratio respectively. Also, TKN decreased 33.26, 82.16 and 84.73% in the 3/1, 1/1 and 1/3 Ratio correspondingly. Conclusion: The results of this study indicated that the applied method is an efficient and economical approach for elimination of COD and TKN from waste leachate. Because it not only is considered as an environmentally friendly method for this regard, but also it will also make economic benefits from methane production.
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.
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.
Ali Asghar Navaei fezabady; Hossein Alidadi; Ali Asghar Najafpoor; Mahmoud Dankoob; Mohsen Yazdani; Masoumeh Saghi; Mohammad Naser Shafiee
Abstract
Background & objective: Evaluation of the effects on environment is an executive view for sustainable development. Solid waste is one of the factors that pollute the environment and the management, control and proper hygiene play a key role in promoting the health of society. So, in establishing ...
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Background & objective: Evaluation of the effects on environment is an executive view for sustainable development. Solid waste is one of the factors that pollute the environment and the management, control and proper hygiene play a key role in promoting the health of society. So, in establishing the composting plants, the environmental issues should be considered and a proper place for these plants must be chosen. This can be one of the most important tasks in waste management programs in developing countries. The aim of this study was to determine the effects of these plants on environment and the procedures to be carried out in this field. Materials & Methods: This research was a review study. By Using the key words (such as compost plants, environmental impact assessment, Iran) the related articles on Web sites google schoolar, iranmedex , SID, Magiran and civilica were searched and studied. Results: In this study, Articles in the period 1995 to 2016 were studied and 40 papers were selected. One paper Environmental impact assessment study methods, One paper method Adkins and Brooke,7 paper method Leopold matrix, one paper matrix math,one paper matrix method of rapid, 2 paper Matrix interactions, the Check list for assessing and one paper matrix type III. Conclusion: In most reviewed studies, the method of Leopold matrix has been used to assess the environmental impact of compost plant. Leopold matrix method has been considered by researchers and experts because of its accuracy, surveying in the construction and operation phases, using two-dimensional tables to express the effects of a compost plant project on the environment, determining suitable place And finally scoring waypoint is placed by specialists for more Compost Plant