فهرست مطالب

Environmental Health Engineering and Management Journal
Volume:4 Issue: 2, Spring 2017

  • تاریخ انتشار: 1396/04/14
  • تعداد عناوین: 8
|
  • Mohammad Hossein Tarmahi, Farid Moeinpour* Pages 65-71
    Background
    Phosphorus is an indispensable element for the growth of animals and plants. There are several environmental problems related to phosphate; therefore, the technical and economic methods of removing phosphate are of great importance. This study evaluated the efficiency of polyaniline/Ni0.5Zn0.5Fe2O4 magnetic nanocomposite in removing phosphate from aqueous environments.
    Methods
    The adsorbent was characterized by several methods, including X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), and Fourier transform infrared (FT-IR) spectroscopy. Then, the potential of the adsorbentto adsorb phosphate was investigated. The effects of the parameters of contact time (5-60 minutes), pH (3-9), adsorbent dosage (0.05-0.6 g), and initial phosphate concentration (2-100 mg/L) on the phosphate removal yield were studied. All phosphate ion concentrations were measured using the ammonium molybdate spectrophotometric method.
    Results
    The results showed that a time of 30 minutes, pH of 5, and adsorbent dose of 0.4 g were the optimum conditions for phosphate removal through adsorption. Increasing the initial concentration of phosphate from 2 to 100 mg/L decreased the removal efficiency from 90.3% to 32%. The experimental data was fitted well with the Freundlich isotherm model (R2 = 0.997).
    Conclusion
    Polyaniline/Ni0.5Zn0.5Fe2O4 magnetic nanocomposite removes phosphate from aqueous solutions with a simple and environmentally benign procedure. The maximum adsorption capacity based on Langmuir isotherm (R2 = 0.931) is 85.4 mg/g. This magnetic nanocomposite is applicable in managing water resource pollution caused by phosphate ions.
    Keywords: Adsorption, Phosphates, Nanocomposites, Polyaniline
  • Nematollah Jafarzadeh, Maryam Ravanbakhsh*, Kambis Ahmadi Angali, Ahmad Zare Javid, Darioush Ranjbar Vakil Abadi, Shirin Ardeshirzadeh Pages 73-79
    Background
    Internal corrosion and the formation of scale in water distribution pipes are the most important problems for an urban water distribution system. Physical, chemical, or biological factors can lead to these two processes. Internal corrosion and scale formation can impact health, economy, and aesthetics. This study assessed the physicochemical quality parameters and evaluated the potential for corrosion and scale formation in drinking water at the distribution systems of 5 selected cities in Bushehr province (Kangan, Dashtestan, Dashti, Bushehr, and Ganaveh) from 2009-2012.
    Methods
    This study was carried out based on laboratory data collected from monthly samplings of tap water in the Water and Wastewater Company of Bushehr province during the years 2009-2012. Internal corrosion and scale formation rates were calculated using the Ryznar, Langelier, Aggressive, and Puckorius indices.
    Results
    The results of the Ryznar, Puckorius, Aggressive and Langelier indices indicated that the drinking water in the 5 selected cities of Bushehr province was corrosive. Moreover, the majority of parameters used to determine water quality exceeded Iran’s national standards.
    Conclusion
    It is concluded that there is problem of water corrosion and scaling in drinking water of distribution systems in selected cities.
    Keywords: Bushehr, Water corrosiveness, Scale formation, Saturation index
  • Hamed Fathi Dokht*, Seyed Alireza Movahedi Naeini, Esmaeil Dordipour, Liz Wollsene De Jong, Ebrahim Hezarjaribi Pages 81-91
    Background
    The application of biochar as a soil amendment has achieved popularity and has been found to improve considerably soil nutrient status and plant productivity in low fertile soils.
    Methods
    This study used two different methods to apply sewage sludge and sewage sludge biochar with three replicates in a completely randomized block design. The experiment included (1) control, (2) mulch biochar (20 t/ha), (3) incorporated biochar (20 t/ha), (4) mulch sewage sludge (45 t/ha), and (5) incorporated sewage sludge (45 t/ha). This study aimed to investigate the potential benefits of sewage sludge and its biochar as mulch and incorporated into the top-soil for soil fertility, growth, yield, and shoot nutrient concentration of soybean and the effects of treatments on dry bulk density, water content, and mechanical resistance.
    Results
    The results showed higher values of height, biological yield, grain yield, and number of pods in the biochar mulch treatments (116.5, 10627.01, 4180, and 71.2, respectively). Moreover, it was determined that the addition of biochar and sewage sludge to soil resulted in increased shoot nitrogen (N), phosphorous (P), and potassium (K) concentrations, soil P, soil K, and total soil N (TN) compared with the control plots. Results from this study also showed that biochar and sewage sludge had positive impacts on the physical properties of soil. Bulk density and soil mechanical resistance were decreased, and volumetric water content was increased.
    Conclusion
    Heating sludge removed all pathogens. It is recommended that short- and long-term studies be conducted in the region to investigate further increases in the combined biochar and sewage sludge application rates.
    Keywords: Nitrogen (N), Phosphorous (P), Potassium (K), Pathogens
  • Zeynab Akbarlou, Vali Alipour*, Mohsen Heidari, Kavoos Dindarloo Pages 93-99
    Background
    Considering the severe health and environmental hazards caused by the entry of diazinon toxin into water resources, its removal is very important. Given the high costs of imported adsorbents, this research attempted to evaluate, for the first time, the efficiency of Iranian activated carbon in removing diazinon from aqueous solutions.
    Methods
    In this batch experimental study, the effects of contact time (5-90 minutes), adsorbent concentration (0.5-30 g/L), initial concentration of diazinon (5-50 mg/L), and pH (3-10) on the adsorption of diazinon onto the activated carbon were evaluated. Concentrations of diazinon were measured using a high pressure liquid chromatography (HPLC) instrument. The specific surface area of the adsorbent was determined by BET and BJH methods. The experimental adsorption data was analyzed using Langmuir and Freundlich isotherm models. Pseudo first-order and pseudo second-order kinetics models were employed to determine kinetics. Moreover, data was analyzed using SPSS version 19, and Pearson correlation and analysis of variance (ANOVA) tests were performed at a significance level of 0.05.
    Results
    The optimum contact time, sorbent dose, and pH were 30 minutes, 10 g/L, and 5, respectively. The adsorbent could adsorb diazinon with a removal efficiency of 92.5% under optimum conditions (initial concentration: 20 mg/L). The experimental data was better described by the pseudo-second order kinetic and Langmuir isotherm. A maximum adsorption capacity of 71.4 mg/g was calculated by the Langmuir isotherm model.
    Conclusion
    With respect to the high adsorption capacity of Iranian activated carbon, this sorbent can be considered an efficient adsorbent for the removal of diazinon from aqueous solutions.
    Keywords: Diazinon, Adsorption, Activated carbon, High pressure liquid chromatography
  • Majid Kermani, Mohsen Dowlati, Sevda Fallah Jokandan, Mina Aghaei, Farshad Bahrami Asl, Sima Karimzadeh* Pages 101-108
    Background
    Air pollutants have multiple adverse effects on human health. In this study, the health effects of exposure to carbon monoxide (CO) and SO2 in the air of 6 Iranian metropolises in 2011-2012 were examined.
    Methods
    Raw data was collected from the Iranian Department of Environment and the Iran Meteorological Organization. After validation, the required statistical indices were calculated through programming and modifying temperature and pressure in Excel software. The output of Excel was given to the AirQ model, and the results were presented as the cases of death.
    Results
    The annual mean concentrations of SO2 were 2.45, 1.55, 0.6, 0.55, 1.05, and 3.8 times higher than the guidelines of the World Health Organization (WHO) (20 μg/m3) in Tehran, Mashhad, Isfahan, Shiraz, Tabriz, and Urmia, respectively. The concentrations of CO did not exceed the standard limit in any of the studied cities. The cumulative numbers of total deaths attributed to SO2 were 744, 122, 132, 44, 37, and 107 in Tehran, Mashhad, Isfahan, Shiraz, Tabriz, and Urmia, respectively. The highest mortality rate was found in Urmia at 2.9% followed by Tehran at 1.52%; the lowest rate of 0.46% was found in Tabriz.
    Conclusion
    The results show that of the 6 metropolises, the highest CO mortality rate of about 2.15% belonged to Isfahan followed by Arak with about 1.38%, and the lowest rate of 0.68% belonged to Mashhad. Because of the growing trend of air pollution and its mortality rate and adverse effects, practical solutions for the control and reduction of air pollution in Iranian metropolises are necessary.
    Keywords: Air pollution, Software, Iran, Cities
  • Mahmood Mahdi Barbooti* Pages 109-115
    Background
    Oxytetracycline (OTC) is a widely-used antibiotic; metabolism studies indicate only partial assimilation of it inside the body. Traditional wastewater treatment plants cannot remove OTC, and this results in the release of considerable amounts of the drug into aquatic environments. There is much concern over the role of residual antibiotics in the development of new generations of bacteria with modified resistance to the antibiotics. The present work investigated the possibility of OTC sorption on river sediments.
    Methods
    Seven sediment samples were collected from various locations and depths of the Passaic River in New Jersey. The texture, clay, extractable iron, and organic matter contents of the sediments were determined. Pyrolysis-gas chromatography-mass spectrometric (Py GC-MS) analysis indicated the presence of 3 categories of organic materials: petroleum hydrocarbons, anthropogenic, and plant residual materials. The sediment samples were equilibrated with OTC solutions for 24 hours followed by centrifugation and syringe filtration. The residual OTC contents were determined by high performance liquid chromatography.
    Results
    It appeared that 35%-60% fractions of OTC were retained by the sediments. The sorption capacity values of the sediments were correlated with clay content, organic matter content, and available iron. A poor correlation was found between adsorption capacity and clay content in the presence of organic matter and iron. Meanwhile, a relatively strong correlation was found between adsorption capacity with the iron, R2 = 0.7499, and organic matter contents of the sediments, R2 = 0.7899. Thus, the sorption of OTC on sediments is governed by all constituents.
    Conclusion
    It was concluded that the antibiotic-sediment interaction is controlled mainly by the organic matter and iron contents.
    Keywords: Oxytetracycline, sorption, Passaic River sediment, Organic matter, Pyrolysis gas chromatographymass spectrometry, Py GC-MS
  • Akbar Eslami, Zeinab Gholami, Shokofeh Nargesi, Bahareh Rostami, Moayed Avazpour* Pages 117-122
    Background
    Today in the world, disease resulting from food is considered one of the most important problems in public health. This study aimed to determine the bacterial contamination of ready-to-eat foods, i.e. fast food, in Ilam city.
    Methods
    In this cross-sectional, analytical study, 270 samples of ready-to-eat food, including pizza, frankfurters, and sausages, were randomly collected and tested for contamination with Staphylococcus aureus, Escherichia coli, Shigella sonnei, Salmonella arizonae, and Enterococcus faecalis. After examination, the collected data was analyzed using SPSS 20 software and logistic regression.
    Results
    From a total of 270 samples of ready-to-eat food, 27.77% was contaminated with E. coli, 21.48% with S. aureus, 13.33% with S. sonnei, 14.44% with S. arizonae, and 5.9% with E. faecalis. The results showed higher rates of E. coli and S. aureus contamination in pizza, frankfurters, and sausages. Also, a higher percentage of frankfurters were contaminated with microbial species than pizza or sausages. There were significant differences in microbial contamination rates (P
    Conclusion
    Based on the results, it can be concluded that bacterial contamination of ready-to-eat foods is significantly high in the city of Ilam; therefore, it is suggested that the examination of food in various stages of production and distribution can help reduce bacterial contamination, and training for the operators of shopping centers’ ready-to-eat food shops and controlling pathogens are essential.
    Keywords: Microbial contamination, Food, Pizza, Frankfurters, Sausages
  • Salar Omid, Zahra Derakhshan, Mehdi Mokhtari* Pages 123-129
    Background
    Due to the lack of a proper waste management system, Tehran Municipality Region 20 is facing economic and environmental problems such as the high costs of a disposal system and source pollution. Life cycle assessment (LCA) is a method for collecting and evaluating the inputs, outputs, and potential environmental impacts of a product system throughout its life cycle. The current study purposed to provide a stable and optimized system of solid waste management in Tehran Municipality Region 20.
    Methods
    The LCA method was used to evaluate various scenarios and compare the effects on environmental aspects of management systems. Four scenarios were defined based on existing and possible future waste management systems for this region. These scenarios were considered with different percentages for source separation, composting, recycling, and energy recovery.
    Results
    Based on the results of this study, Scenario 4 (source separation [14%] composting [30%] municipal recycling facility [MRF] [20%] energy recovery [10%] landfilling [26%]) was found to be the option with the minimum environmental impact. In the absence of government support and sufficient funds for establishing energy recovery facilities, the third scenario (source separation [14%] composting [30%] ㄑ [20%] landfilling [36%]) is recommended.
    Conclusion
    The results acquired from this investigation will confirm the belief that LCA as an environmental device may be successfully used in an integrated solid waste management system (ISWMS) as a support tool for decision-making
    Keywords: Municipal solid waste management, Life cycle assessment, Waste management, Tehran