zahra jafari; Amir Salemi
Abstract
AbstractIntroduction: Reaction of disinfection reagents, particularly chlorine, with natural organic material existing in raw water, results in production of a wide range of organic compounds, also known as disinfection byproducts. Despite their sever impacts on human health, only a tiny fraction of ...
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AbstractIntroduction: Reaction of disinfection reagents, particularly chlorine, with natural organic material existing in raw water, results in production of a wide range of organic compounds, also known as disinfection byproducts. Despite their sever impacts on human health, only a tiny fraction of disinfection byproducts is regulated and controlled.Materials and methods: In the present work, a novel solid-phase microextraction Arrow coupled with GC-MS has been developed, optimized and implemented for determination of seven non regulated disinfection byproducts; trichloroacetonitrile, dichloroacetonitrile, 1,1-dichloro-2-propanone, chloropicrin, bromochloroacetonitrile, 1,1,1-trichloro-2- propanone and dibromoacetonitrile. A central composite design was used to optimize the extraction parameters. Results and discussion: The method was sensitive enough to detect traces of the target compounds, with LOD values of 1.4-62 ng L-1. Also, quantitative analysis was possible over a wide linear range of about four orders of magnitude (50 to 100000 ng L-1 with R2 values of more than 0.997) with reasonable precision (RSD% values of less than 21.6% at 50 ng L-1. relative recoveries were between 60 and 95 %.Conclusion: The optimized technique was also successfully implemented for determination of the target compounds in ten drinking water samples and as result, most of them were observed in various concentration levels.
Neda Mirikaram; Amir Salemi; Maryam Vosough
Abstract
Introduction: pharmaceuticals, personal care products and steroid hormones are emerging pollutants whose main production source is human societies. Municipal wastewater treatment plants have a very effective role in reducing and eliminating these pollutants, however, complete elimination of these compounds ...
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Introduction: pharmaceuticals, personal care products and steroid hormones are emerging pollutants whose main production source is human societies. Municipal wastewater treatment plants have a very effective role in reducing and eliminating these pollutants, however, complete elimination of these compounds is usually not possible and some of these pollutants are treated through the treated wastewater stream (as well as residual sludge) and enter the environment. Due to the use of treated wastewater in the irrigation of fields and orchards, there is a possibility of transferring contaminants to soil, crops, and groundwater. Since the negative effect of the presence of these contaminants is visible in very low concentrations, it is necessary to identify and determine their amount.Material and methods: In this study, the transfer channel of the treatment plant in the south of Tehran (raw wastewater, treated wastewater), farm soil, and crops in terms of the presence and amount of emerging organic pollutants, from the category of pharmaceuticals and steroid hormones have been studied. Four samplings of treated wastewater were performed in different places. First, qualitative analysis was performed to identify and select target pollutants (for quantitative measurement). Then, the most important quality assurance and control criteria in the field and laboratory were studied so that the data generated had the highest possible level of quality. Finally, each sample for each category of pollutants was separately prepared and extracted. Solid phase and solvent extraction were ultrasonically analyzed and finally analyzed by gas chromatography-mass spectrometry.Results and discussion: Two pharmaceuticals, acetaminophen and sulfamethoxazole, and four steroid hormones, aquiline, estrone, estriol, and ethinyl estradiol, were selected as the target contaminants and the most important and continuous ones. All six analytes were identified in a raw wastewater sample and a treated wastewater sample. In another sample of treated wastewater, aquiline, estrone, and ethyl estradiol were not found. Contrary to our expectations, all analytes were found in soil samples, but only estrone was found in soil samples. In the plant sample (wheat), all analytes except ethynyl estradiol were observed.Conclusion: All contaminants were observed in raw and treated wastewater (treatment plant effluent) and a very positive role of the treatment plant in reducing the concentration was observed. On the other hand, changes in the concentration of pollutants along the channel path were observed. Also, it was concluded that soil particles do not adsorb the target contaminants despite their tendency to be absorbed by plants. Therefore, the entry of contaminated water into arable soil will lead to crop contamination and infiltration into groundwater. The presence and amounts of contaminants in the treated wastewater treatment canal are highly dependent on time and place. Mixing and diluting and entering new sources of contamination in the canal path causes significant changes in the concentration and type of contaminants observed in the samples.
Mohammad Mahmudi; Seyed Hossein Hashemi; Amir Salemi
Abstract
Introduction: So far, several studies have been carried out all over the world on the development of appropriate indicators for the emission of hydrocarbon contaminants and several indicators have been presented in this regard. These indicators are divided into internal and external categories. External ...
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Introduction: So far, several studies have been carried out all over the world on the development of appropriate indicators for the emission of hydrocarbon contaminants and several indicators have been presented in this regard. These indicators are divided into internal and external categories. External indices determine the source of hydrocarbon pollution based on the ratio of metals in the oil, such as the ratio of nickel to vanadium. In contrast, indigenous indices, namely aromatic and aliphatic compounds, are used mainly for the propagation of hydrocarbon contamination. Because of the difference in reactivity, solubility, and thermodynamic properties between some polycyclic aromatic hydrocarbons isomers, they can be used to determine the source of hydrocarbon pollution. Material and methods: In many studies on hydrocarbon contamination, only one of the aliphatic or aromatic compounds in the water, soil and sediment environment is investigated. However, in this study, for the determination of hydrocarbon contamination in the south of Tehran, aromatic and aliphatic compounds were investigated in all water, soil, and sediment environments. To determine the amount of contamination, 33 samples of water, soil, and sediment were collected. After collection, the samples were immediately transferred to the laboratory and extraction of hydrocarbon compounds was done. Water samples were collected from wells, aqueducts, surface waters, and canals. Soil samples were obtained from surface and 50 cm depth of agricultural land, and primer soil and sediment samples were collected from sediments accumulated in canals, aqueducts and surface waters. Results and discussion: In this study, 16 important PAH compounds that are declared as carcinogenic by the US Environmental Protection Agency and aliphatic compounds (C8-C40) were studied. The average concentration of PAHs compounds in water samples was 2127.72 ppb ranging from 5 to 147125.56, in soil samples was 6715.7 ppb, ranging from 5 to 446642, and in sediment samples was957.77 ppb ranging from5 to11992.02. As for aliphatic compounds (C8-C40), their concentrationin water samples was 39.50 ppm with a range of 5-785.2, in soil samples was 1110 ppm with a range of 5-16160/74, and insediment samples was1751.13 ppm with a range of 5-30497.37. The presence of hydrocarbon contamination in the south ofTehran showed that petroleum pollution is petrogenetic. According to these results, the most contamination was observed insamples around the pond of oil waste and samples near the oil pipelines, where the hydrocarbon contamination can penetrateinto the groundwater and the soil. Also, the oil pollution in the area was not limited to the oil refinery, but part of it was relatedto the liquefied gas collection from the city and transportation to the canals to use for irrigation of agricultural land. Regardingthe comparison of concentrations of PAH and aliphatic compounds, the highest concentrations of PAHs were found in waterand sediment, respectively, and the highest concentrations of aliphatic compounds were in the soil, sediment, and water, respectively,respectively. Due to the fact that the hydrocarbon compounds in the water column are deposited into the channel depositsand these channels are periodically dredged by farmers in the region, there is no possibility of accumulation of high levels ofhydrocarbons in these environments. For this reason, the highest concentrations are in the soil environment. Conclusion: The results of measurement and analysis of oil hydrocarbons in water, soil, and sediment environmentsshowed that oil pollution is petrogenetic. Most of this pollution is related to oil spills from Tehran refinery and the otherreason is the collecting channels of urban surface runoff, which are contaminated with petrogenetic petroleum compoundsthat lead to the south of Tehran.
Reyhaneh Sadat Ghazi Marashi; Omid Noori; Reza Deihimfard; Amir Salemi
Volume 15, Issue 4 , January 2018, , Pages 113-124
Abstract
Introduction:
Urbanization and population growth, in addition to its rapid development across the world, has caused a major demand for the food security and the self-sufficiency in terms of food production in many cities. According to the aforementioned circumstances, the activities in the basis of ...
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Introduction:
Urbanization and population growth, in addition to its rapid development across the world, has caused a major demand for the food security and the self-sufficiency in terms of food production in many cities. According to the aforementioned circumstances, the activities in the basis of urban agriculture with different traditional methods (e.g. planting on the ground surface with a soil bedding) or the modern ones (e.g. rooftop gardening with hydroponic cultivation methods) have been emerged and numerous studies regarding these methods have been accomplished. Likewise, a large number of farms in the urban areas came into existence worldwide. Nonetheless, there are yet various challenges to develop this type of agriculture. Moreover, only few numbers of studies were carried out to monitor the health and hygiene condition of the food productions grown in such places, especially in terms of air pollutants accumulation. The objective of this research was to study the hygiene of the plants cultivated in urban environment (rooftops and courtyards), and to determine the accumulation rates of pollutants in the eggplant fruit (Solanum Melongena var. depressum (L.)) and bell peppers (Capsicum fruitescens var. grossum (Mill.)).
Materials and methods:
Two types of vegetables; bell pepper and eggplant were cultivated in the rooftop and courtyard of a five story building in the 7th district of Tehran. The seeds were planted on the basis of a completely randomized design system using six times repetitions. Besides, in order to compare the hygiene of these fruits with those of the fruits cultivated in the countryside, similar samples of the same products were used in the farms located in the environs of Varamin and Karaj. Densities of heavy metals such as molybdenum, chrome, copper and manganese ( Mn, Mo, Cr and Cu) included in the fruits of belle pepper and eggplants cultivated in the urban areas of Tehran were compares with their amounts in the fruits cultivated in the farms located outside of the towns. Additionally, the amounts of heavy metals Lead and Cadmium (Cd, Pb) in the samples related to the city of Tehran were compared to the European Union Standards and the Iranian National Standard. The sample digestion was carried out using Microwave, and in order to analyse and measure the results, the device of ICP-MS was used. Data was analysed by the SAS and Microsoft Excel software and the means comparison was done through standard error.
Results and discussion:
The resulted data demonstrate that the densities of heavy metals in the most of the fruits grown in city showed significantly higher numbers in the range of 5% than those of plants grown in countryside, except the contents of chrome in eggplant which is higher in the samples of the farms located in the countryside than those of both urban areas. Moreover, the heavy metal pollutants of copper in both eggplant and bell pepper from the farms located in countryside were higher than the samples of the rooftop. The chrome density in the eggplants cultivated in farmland was 1.56 times more than that of courtyard, and 1.58 times more than that of rooftop. Densities of copper in the eggplant and bell pepper of countryside farm are respectively 1.22 and 1.24 times more than the samples of rooftop. Furthermore, except lead contents (Pb) being observed at three different levels 0.18, 0.63 and 0.14 milligrams per one kilogram of dry weight (mg/kgDW) in some samples, respectively for rooftop eggplants, rooftop bell peppers and bell peppers of courtyard, which showed significant variances to the permissible limits (in the range of 5%), other samples indicated acceptable amounts of lead and cadmium with respect to the European Union Standard and Iranian National Standard (under the limits of 5%).
Conclusion:
In general it can be concluded that all the samples cultivated in the urban areas of 7th district of the city of Tehran were healthy in terms of allowable amounts of Cadmium as an heavy metal. These density ratios fully complied with international standards, and were similar to those of the samples cultivated in the countryside. In contrast, most of the aforementioned samples contained the impermissible amounts of lead heavy metal. Likewise, the densities of other heavy metals included in products of urban farms were much higher than those of the city exteriors. As a matter of fact, this difference might be resulted from the effects of heavy traffic flow, geographic position and the unsuitable climate conditions on the air quality of urbanized areas.
Amir Salemi
Volume 11, Issue 4 , January 2014
Abstract
Different classes of pesticides are used during production of various tea products. Beside their health impact on the consumers, these pesticides are likely to be released into the different natural media and affect the exposed environment. To help predict chromatographic behavior of these pesticides, ...
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Different classes of pesticides are used during production of various tea products. Beside their health impact on the consumers, these pesticides are likely to be released into the different natural media and affect the exposed environment. To help predict chromatographic behavior of these pesticides, the gas chromatographic retention behavior of 57 of these pesticides were modeled using quantitative structure-retention relationship approach. The most important descriptors encoding structural and topological properties of the studied compounds were showed to be in a linear relation with their retention time. A stepwise variable selection strategy in MLR modeling resulted in models with acceptable R2 values of which a model based on five molecular descriptors was selected to compromise between high R2 values and low variable numbers. The selected descriptors were VRD2, X1sol, Rww, MLOGP and More09e. The model was tested for its prediction capability, by examining a prediction set of randomly selected compounds (10 pesticides) and the average of the prediction error was used as the criteria. The model, regarding its simplicity, was successful in predicting the retention times of the proposed set of compounds.
Babak Jafari Salim; Gholamreza Nabi Bidhendi; Amir Salemi; Masoud Taheryioun; Mojtaba Ardestani
Volume 6, Issue 4 , July 2009
Abstract
Comprehensive information and knowledge about the quality of water resources plays a very important role in preservation plans for water resource management. One of the engineering methods used to assess river water quality conditions without mathematical and statistical complexity is water quality indices. ...
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Comprehensive information and knowledge about the quality of water resources plays a very important role in preservation plans for water resource management. One of the engineering methods used to assess river water quality conditions without mathematical and statistical complexity is water quality indices. In this method, different water quality parameters are analyzed and interpreted in a river water quality assessment study. It is one of the most important parts of river quality monitoring plans in which the qualitative indices are converted to a single and dimensionless number. Water quality classification is undertaken on the basis of the value of the indices comparing with a predefined rated scale. In this study, a monitoring plan is achieved for the 18 stations located along with Gheshalgh River in Kurdistan province in Iran. Water quality assessment has been conducted using two NSF quality indices of general water use and the British Columbia index for drinking and agricultural consumption. Based on the results obtained from these indices, water of this river has the worst quality due to agricultural use downstream of the wastewater treatment plant of Sanandaj city. Its condition is degraded up to the discharge point of Morghe Par slaughterhouse due to the assimilation capacity of the river. In this location water quality is acceptable for drinking purposes and most of the stations have appropriate conditions except for Dare Kuleh and the downstream station which are on the border. Results indicate that the degree of influence of urban pollutant sources such as entry of urban wastewater and also of a landfill leachate brook is high, especially in the Gheshlagh bridge area up to the tributaries.
