Saeid Ahadi; َAndisheh Alimoradi; Hamid Sarkheil; Mahyar Kalhor Mohammadi; Mahdi Fathi
Abstract
Introduction: The process of extraction and exploitation of oil and gas resources requires the cycle of production, sending, and recycling of drilling mud or drilling fluid, so achieving the right combination of drilling mud and its recycling is an essential and fundamental matter in the industrial oil ...
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Introduction: The process of extraction and exploitation of oil and gas resources requires the cycle of production, sending, and recycling of drilling mud or drilling fluid, so achieving the right combination of drilling mud and its recycling is an essential and fundamental matter in the industrial oil and gas and also the environment.Material and methods: Determining the level of contamination of heavy metals and organic matter in the drilling mud and drilling cuttings can be necessary so that intelligent methods to estimate these contaminants can be indirectly effective. This study tried to estimate the contamination rate of drilling cuttings, despite the formation parameters of 10 oil wells drilled at different depths (66 data sets), using the regression learning limit of an artificial neural network.Results and discussion: A total of 60 data sets were prepared to estimate the rate of change in the concentration of heavy metals, polycyclic aromatic hydrocarbons in the learning and testing process, and another six sets of data related to a well that was randomly selected and used in the artificial neural network validation process. Limit learning regression algorithm for ten heavy elements and ten aromatic compounds contaminating cutting and drilling mud on two different data sets in a drilling area in one of the oil fields in southern Iran was evaluated.Conclusion: The results are suitable for estimating the contamination of drilling cuttings and subsequent environmental protection processes. Such processes of contamination and recycling of drilling mud will play an efficient role.
Zhaleh Amini; Reza Anvaripour; masoud Hatami-manesh; Jaber Aazami
Abstract
Introduction; Due to the potential toxicity and ecological risk of heavy metals in aquatic ecosystems, measuring and evaluating their concentration in different parts of aquatic environments is very necessary. Therefore, the present study measures the concentrations of Cd, Cr, Pb, Ni, As and Zn and evaluates ...
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Introduction; Due to the potential toxicity and ecological risk of heavy metals in aquatic ecosystems, measuring and evaluating their concentration in different parts of aquatic environments is very necessary. Therefore, the present study measures the concentrations of Cd, Cr, Pb, Ni, As and Zn and evaluates the spatial distribution of their ecological risk in the surface sediments of Anzali International Wetland.Materials and methods; 50 stations in different parts of the wetland were selected for sampling. After preparation and acid digestion of samples, the concentrations of these metals were determined by an atomic absorption spectrometer. In order to zoning the toxicity and ecological risk of metals, the inverse distance weighting (IDW) method was used.Results and discussion; The total mean concentrations of metals were Zn (79.24 71 6.71), Cr (19.4 21 21.04), Ni (18.96 62 5.62), Pb (13.3 72 72.50), As (7.62 96 4.96) and Cd (1.12 ± 3.16) mg/kg, respectively. Investigation of potential acute toxicity, RI, mHQ and PLI indicated low pollution status in wetland sediments. The environmental risk of the metals in the sediments were evaluated as (Cd> As> Pb> Ni> Zn> Cr). In addition, the distribution of toxicity and ecological risk of metals in different parts of the wetland does not follow the same pattern and the western parts of the wetland have more risks. Conclusion; According to the results, Potential acute toxicity, PLI, mHQ and ecological risk of heavy metals in the sediments of the region are assessed as low and medium. The intense expansion of human activities in the areas around the wetland, along with the deposition and entry of various pollutants in this ecosystem, confirms the need for continuous monitoring of the wetland and assessment of its ecological health risk.
Maryam Rabiee Abyaneh; Gholamreza Nabi Bidhendi; Ali Daryabeigi Zand
Abstract
Introduction: Landfill leachate is a highly toxic and hazardous form of wastewater due to its complex composition characteristics. Effective removal of heavy metals from landfill leachate is of great concern due to the fact that toxic metals can seriously threaten the food chain, and therefore the human ...
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Introduction: Landfill leachate is a highly toxic and hazardous form of wastewater due to its complex composition characteristics. Effective removal of heavy metals from landfill leachate is of great concern due to the fact that toxic metals can seriously threaten the food chain, and therefore the human health. The main objective of this work was to study the utilizing of low-cost pruning residues in the production of biochar and its application in removal of lead (Pb) from landfill leachate.Material and methods: Leachate produced in Babol municipal solid waste landfill was used as an adsorbent solution. Pruning residues were collected and used for biochar preparation. Biochar produced under the pyrolytic temperature of 700°C with a 1-hour retention time. The adsorption mechanism of pruning waste biochar to Pb was analyzed through BET surface area and scanning electron microscope (SEM) tests. Batch experiments were performed to study the effects of adsorption parameters on Pb removal. The influence of contact time (30-300 min), adsorbent dosage (1-50 g/L), as well as particle size (1-2 mm and 63-75 µm) was investigated. Moreover, the kinetic and isotherm models were applied to the experimental data to predict the adsorption parameters.Results and discussion: The results obtained from the analysis of the untreated Babol landfill leachate was revealed that the Pb concentration was about 4.94 mg L-1. The surface area of the produced biochar was determined to be 292.44 m2 g-1. SEM microstructure of the biochar showed the developed surface area with visible pores. All of these data seem to suggest a great potential for pruning residues biochar to Pb removal. The adsorption of Pb was mainly affected by contact time, adsorbent dose, and biochar particle size. Higher contact time and adsorbent dosage showed higher uptake of Pb. Whereas, the uptake of Pb ions onto pruning residues biochar was substantially reduced with increase the biochar particle size. Maximum Pb percentage removal was observed at a contact time of 90 min and with an optimum biochar dosage of 20 g L-1 (89.06% removal) for biochar with 1-2 mm particle size. While, biochar with particle size of 64-75 µm can removed Pb to almost 100% at a contact time of 120 min and with an optimum biochar dosage of 20 g L-1. The kinetic study showed that adsorption can be well described by the pseudo-second order kinetic model. This supports the chemisorption theory behind the pseudo-second order kinetic model for the adsorption system. The results of isotherm models implied that the behaviors of the isotherms are more appropriate for the Langmuir model, showing a monolayer adsorption capacity for Pb.Conclusion: Findings of this research demonstrated the applicability of pruning residues biochar as an economic adsorbent for the removal of the Pb from landfill leachate. On the other hand, the crop residue burning poses a threat to the environment and human health due to the emission of toxic gasses and particulate matter. So, conversion of pruning residues to biochar and its application to heavy metal removal is a useful and environment-friendly alternative to crop residue and biomass burning.
Parisa Mashayekhi; Hosein Sharifi
Abstract
Introduction: In recent years, the increased water, soil, and environmental degradation, due to the excessive use of chemicals, has encouraged researchers into organic farming. Despite all the positive effects associated with the consumption of sewage sludge and municipal compost on the soil physical ...
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Introduction: In recent years, the increased water, soil, and environmental degradation, due to the excessive use of chemicals, has encouraged researchers into organic farming. Despite all the positive effects associated with the consumption of sewage sludge and municipal compost on the soil physical and chemical properties, there is still a great concern in terms of the environment, agriculture and health. Depending on the source, composts often contain relatively large amounts of heavy metals, and thus accurate measurement of heavy metal contents in these compounds is important.Material and methods: In this study, 20 compost samples from different sources, including manure, municipal waste and sewage sludge sources were selected. Five methods of digestion in three replicates were used to extract the heavy metals of the compost samples, including nitric acid, dry ashing, nitric–perchloric acid, sulfuric acid and sulfosalicylic acid methods. The elements were Cd, Pb, Ni, Cr, Co, Cu, Zn, Mn, and Fe.Results and discussion: Analytical results indicated that the nitric–perchloric acid procedure was the most efficient for recovering Cd, Pb and Cr from the organic samples. After that, dry ashing method extracted the highest amount of Cd, Pb and Cr from all compost samples (on average). Since perchloric acid is potentially hazardous during digestion procedure, dry ashing was recommended as an alternative method. The recovery of Cd and Pb in the organic compounds is affected not only by the digestion method, but also by the type of compost. For example, the nitric–perchloric acid procedure recovered more Cd and Pb from municipal waste and sewage sludge than manure and Poultry fertilizers. In the case of other elements including Ni, Co, Cu, Mn, Zn and Fe, sulfosalicylic acid has the highest efficiency in extracting these elements from compost samples. Extraction of these elements was only affected by the type of extraction method and the type of organic composition had no effect on it.Conclusion: Different digestion methods and also different compost sources that were tested had a very significant effect on the extraction of all heavy metals. Despite the fact that the organic compounds used in this experiment had a relatively wide range in terms of various structural and chemical properties, the digestion methods used for the heavy and micronutrient elements in these compounds had a relatively specific trend in terms of the extraction potential of these elements. In general, in the case of heavy metals, Cd, Pb and Cr, nitric acid + perchloric acid and then dry digestion method, had the best efficiency in extracting these elements. For the other elements including Ni, Co, Cu, Mn, Zn and Fe, sulfosalicylic acid was the most effective in extracting these elements from compost samples.
Kimia Fotovvat; Leila Khazini; Yousefali Abedini; Mohammadreza Yousefi
Abstract
Introduction: Today, with the expansion of the activity of industrial units, the concentration of pollutants in the air has increased and humans are exposed to them through inhalation, ingestion, and dermal absorption. Among all pollutants, heavy metals have received a great deal of attention from environmentalists ...
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Introduction: Today, with the expansion of the activity of industrial units, the concentration of pollutants in the air has increased and humans are exposed to them through inhalation, ingestion, and dermal absorption. Among all pollutants, heavy metals have received a great deal of attention from environmentalists due to their toxic nature. High concentrations of heavy metals in the environment can increase the risk of adverse effects on human health. Activity of copper casting units and its alloys made Naji Industrial Town of Zanjan as a main source of heavy metals in the atmosphere; therefore, evaluating the concentration and health effects of heavy metals emitted from the town is of particular importance.Material and methods: To evaluate the concentration and health effects of heavy metals emission from the industrial units of Naji Industrial Town, sampling of total suspended particles in the town and its adjacent areas (10 stations) was performed in January and May 2021. Inductively coupled plasma mass spectrometry (ICP-MS) was used to identify heavy metals. The risk of cancer and non-cancerous diseases due to respiration, ingestion and skin absorption of heavy metals in total suspended particles was also evaluated for both age groups of children and adults.Results and discussion: In this analysis heavy metals e.g. silver, arsenic, cadmium, chromium, copper, iron, lead, antimony, vanadium and zinc were identified. The concentrations of detected heavy metals were compared with national ambient air quality standards. The concentration of chromium and iron in all stations within Naji Industrial Town was higher than the standard level. Also, the concentrations of silver, cadmium, chromium, copper, iron, antimony, vanadium, and zinc in all stations adjacent to the Industrial Town was higher than the standard. The results of assessing the risk of non-cancerous diseases by exposure to heavy metals in total suspended particles, both in winter and spring, showed that exposure to heavy metals in all stations does not pose a risk to public health. The highest risk of cancer in winter and spring was due to exposure to the arsenic (at station 2, inside the industrial town) and cadmium (at station 4, inside the industrial town), respectively. In spring, the risk of cancer due to exposure to arsenic and cadmium was higher in all stations except station 2 than in winter. However, in the spring, the risk of cancer in all stations was lower than in the winter. The risk index values for the age group of children were higher than the age group of adults; therefore, children are more at risk for various types of cancer and non-cancerous diseases while exposing to heavy metals in the air.Conclusion: The results of the assessment of exposure to heavy metals released from Naji Industrial Town on human health show that the risk of non-cancerous diseases does not threaten the people of the study area; but the risk of cancer caused by the arsenic and cadmium is high at most of the surveyed stations.
Sahebeh Hajipour; Morteza Mohammadi Deylamani; Mohadeseh Momen Zadeh; Mansour Afshar Mohammadian
Abstract
Introduction: plant remediation is cost-effective and environmentally friendly, in which the plant uses its natural abilities to restore the environment. Plants used for phytoremediation must have the ability to accumulate large amounts of metal pollutants without causing toxicity in them. Today, with ...
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Introduction: plant remediation is cost-effective and environmentally friendly, in which the plant uses its natural abilities to restore the environment. Plants used for phytoremediation must have the ability to accumulate large amounts of metal pollutants without causing toxicity in them. Today, with the increase in the world's population and the development of industries and factories, the amount of wastewater entering the environment, which often contains heavy metals and various pollutants, increases. Heavy metals have destructive effects on the health of plants and animals in different ecosystems. Considering the ability of heavy metals to accumulate and cause toxicity in living organisms, this type of pollution is considered a serious and fundamental problem. The use of plants as an effective and cost-effective technology to remove metal pollutants from contaminated soils and waters has been recommended as a new method instead of other costly measures. Therefore, the removal of pollutants from soil and polluted waters with the help of plants through absorption and accumulation in roots, stems and leaves is considered as one of the purification methods to remove metal pollutants. In this process, choosing the right plant with high absorption capacity and compatible with the environment, without negative environmental effects, plays a very effective role in the amount of pollutant purification.Material and methods: In this regard, in order to investigate the uptake and accumulation of heavy metals by plants, an experiment was conducted in a completely randomized design with three replications using vetiver plant. Plants treated with industrial effluent and control plants were irrigated with municipal water. Also, pots containing soil without plants were considered to measure the amount of elements in the soil during the six-month experiment period, they were regularly irrigated with other pots with industrial effluent. In order to investigate the effect of irrigation with effluent on the yield of vetiver plant, after a six-month period of experiment, heavy element analysis and anatomical and physiological studies were performed on plants treated with industrial effluent and control plants. Transfer and accumulation factors, which are two important factors in measuring plant ability for phytoremediation, were also examined.Results and discussion: The results of this study showed that among the most heavy metals in industrial effluents, which included zinc and chromium, most of the mentioned elements were stored in the roots of vetiver and less were collected in the aerial parts. Also, the results of physiological traits experiments showed that the factors of soluble sugars and proline in the treated plants increased compared to the control and the concentration of malondialdehyde in the treated plants decreased compared to the control. The results of root studies in control and treated plants showed that root diameter, central cylinder diameter and number of vascular clusters in treated plants increased compared to control.Conclusion: Overall, the results of this study showed that in the process of absorption of heavy metals, changes were made in some anatomical and physiological traits of treated plants. Examination of transfer and bioaccumulation factors also showed that vetiver has the ability to absorb zinc and chromium through plant stabilization.
Maliheh Jamali; Javad Bayat; Seyed Mohammad Reza Talakesh; Seyed Hossein Hashemi
Abstract
Introduction: As a result of human development and population growth, there is a corresponding need for essential resources for humans. Industrial and agricultural activities have greatly polluted most agricultural lands. Petroleum compounds and heavy metals, both are common pollutants of soils that ...
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Introduction: As a result of human development and population growth, there is a corresponding need for essential resources for humans. Industrial and agricultural activities have greatly polluted most agricultural lands. Petroleum compounds and heavy metals, both are common pollutants of soils that have been irrigated by untreated wastewater, which pose a potential threat to the environment. Soil pollution of the agricultural lands will lead to a decline in cultivation and finally decrease food production. Agricultural lands in the southern part of Tehran are being irrigated with untreated wastewater for more than 30 years to produce a variety of vegetables, legumes, and cereals.Material and methods: In this study, the concentration of heavy metals and petroleum compounds were determined in 83 sampling points at two depths (0 to 30 and 30 to 60 cm). The study area was divided into two separate zones, in which 44 points were located in zone 2 and 39 points were located in zone 1. Petroleum hydrocarbons and heavy metals, As, Cd, Co, Cr, Cu, Ni, Pb, V, and Zn, were measured at the top and subsoil by MOOPAM and ICP-AES methods, respectively. ArcGIS and R software were applied to create distribution maps of the pollutants and some statistical analyses.Results and discussion: The results showed that the soil of agricultural land in the area is highly polluted, as the concentration of Cr, Pb, Co, and Ni has exceeded the standard level e.g. 0.22 mg/kg for Cd and 620 mg/kg for Pb. The concentration of petroleum compounds in wastewater irrigated lands in both top and subsoil was higher than that of groundwater irrigated lands. High levels of As, Cr, Cu, Pb, and Zn were observed in groundwater irrigated lands compared with wastewater irrigated lands. Cr and Pb were almost 89 and 8 times higher than the standard limit of agricultural lands in Iran, respectively. The spatial distribution map of petroleum compounds showed that only the southeast of the area falls into the heavily contaminated class. The distribution map of heavy metals also revealed that most parts of the studied area fall into the heavily contaminated class. Soil organic matter has more concentration in the topsoil.Conclusion: Overall, the south of the studied area has been more affected by wastewater irrigation, agrochemicals and groundwater pollution in terms of heavy metals and petroleum compounds. Our study revealed various anthropogenic pollution sources, which are mostly from wastewater irrigation and the application of agrochemicals. Therefore, a management plan should be applied to the agricultural lands of this region to control and reduce the level of contamination.
Kamal Siahcheshm; Mahnaz Mohammadi; Saied Mohammad Sorouraddin
Abstract
Introduction: Oxidation of sulfide mineralized zones during the weathering processes is intensified by biological and chemical reactions and the resulting Acid Mine Drainage (AMD) causes the release and mobility of toxic and heavy metals from the parent rock and their concentration in soil or water. ...
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Introduction: Oxidation of sulfide mineralized zones during the weathering processes is intensified by biological and chemical reactions and the resulting Acid Mine Drainage (AMD) causes the release and mobility of toxic and heavy metals from the parent rock and their concentration in soil or water. In this study, soil samples taken from the surroundings of the village of Doustbaglu (northwest of Meshginshahr), which is considered a typical mineralization and alteration area, were studied and chemical species, toxicity, and origin of heavy elements were determined.Material and methods: In this study, total concentration and bioavailability of heavy elements i.e. As, Cd, Cu, Cr, Pb, Sb, Ni, and Zn in five surface soil samples were evaluated by Tessier sequential extraction method in five phases (exchangeable, connected to carbonate, bound to iron and manganese oxides, bound to organic matter, and residual phase) and using the Visual Minteq thermodynamic software.Results and discussion: The results of the sequential extraction method showed that the highest concentration of the total concentration of all studied heavy elements was retained in the residual fraction (stabilized in the mineral structure). This indicates the geogenic origin of these elements and can be considered the result of erosion and weathering of rocks in the region. Compared to other elements, Sb had a higher concentration in potentially available fractions (e.g. exchangeable, carbonate-bound, bound to Fe-and Mn-oxides, and/or organic matter) and can be readily available to plants and toxic. The software output delineates that the predominant species in the examined samples were lead as Pb (SO4)22-, Pb2+ and PbSO4(aq); copper as CuSO4 (aq) and Cu2+; nickel as NiSO4 (aq), Ni2+ and NiSO4; antimony as Sb(OH)3, Sb(OH)2+ and Sb(OH)61-; zinc as Zn(SO4)22-, ZnSO4(aq) and Zn2+; arsenic as H3AsO3 and H2AsO4-; cadmium as Cd(SO4)22-, and Cd2+. The predominant species of chromium were CrSO4+, CrOHSO4(aq), and HCrO4-. In general, the free water-soluble species of these elements were more mobile than other species; instead, the concentration of these species was very low relatively, and most of these elements were more present in the form of complexes with low mobility.Conclusion: Based on sequential extraction results, all studied elements showed high ecological risk potential and significant pollution in the sediment of waterways and surface soil horizons of the Doustbaglu area. Analysis of the findings of Visual Minteq software indicates that the most active types of elements and related concentrations, among all possible types, include: Cd2+(1.49%), CrOHSO4(aq)(25.20%), Cu2+(10/38%), Pb2+(1/37%), ZnSO4(aq) (18.83%), respectively. Since more mobile species have low concentrations and on the other hand, according to the results of sequential extraction, most of the studied elements are present in the remaining phase, so the bioavailability and toxicity of these elements are estimated to be negligible. In general, it can be concluded that only a small percentage of elements are present in bioavailable fractions, and this can alleviate concerns about the possibility of element release by changing environmental conditions and thus accessibility to plants.
Seyedeh Maryam Mohammadi; Bahareh Lorestani; Soheil Sobhan Ardakani; Mehrdad Cheraghi; Lima Tayebi
Abstract
Introduction: Heavy metals are the common pollutants of soils, which pose a potential threat to the public and particularly children's health. Therefore, this study was conducted to assess the source identification and potential ecological risk of Fe, Zn, Pb, Cd, Cr, and Ni in surface soils collected ...
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Introduction: Heavy metals are the common pollutants of soils, which pose a potential threat to the public and particularly children's health. Therefore, this study was conducted to assess the source identification and potential ecological risk of Fe, Zn, Pb, Cd, Cr, and Ni in surface soils collected from the vicinity of Arad-Kouh processing and disposal complex, Tehran, Iran in 2020.Material and methods: In this descriptive study, a total of 30 surface soil samples were collected from 10 sampling sites. After acid digestion of soil samples, the element contents were determined using ICP-OES. Also, pollution indices, potential ecological risk were computed. Moreover, principal component analyses (PCA) and hierarchical cluster analysis (HCA) were performed to find out the contamination sources and distinguish the different groups of analyzed elements from different sources, respectively. Furthermore, all statistical analyses were performed by SPSS software.Results and discussion: Based on the results, the mean content of elements in soil specimens (mg/kg) was 26651.6 for Fe, 71.7 for Zn, 27.7 for Pb, 1.22 for Cd, 22.3 for Cr, and 32.8 for Ni. On the other hand, the soil quality of the study area varied between 'minor enrichment' to 'moderately severe enrichment' based on the enrichment factor (EF) values, between 'low contamination' to 'high contamination' based on the pollution index (PI) values, and between 'unpolluted' to 'moderately polluted' based on the geo-accumulation index (I-geo) values and also showed 'moderate degree of contamination' based on the degree of contamination (DC) values. The computed values of Er showed that the potential ecological risk of Zn, Pb, Cr, and Ni was low and for Cd was moderate. Also, as the mean value of RI was 170.9, all the examined elements could be classified as a moderate ecological risk. The results of Pearson correlation coefficient, I-geo, PI, and IPI in accordance with PCA and HCA indicated that Zn, Cd, Cr, and Ni were originated from anthropogenic sources, while, Pb had a lithogenic origin.Conclusion: Although the studied elements had moderate potential ecological risk, since the Cd with 93.3% of the mean RI values showed a higher potential environmental risk compared to other elements, therefore, source identification and source control of this element with potentially adverse effects on humans and also environmental health is recommended.
Hamid Sarkheil; Meisam Fathi Nooran; Mojtaba Kalhor; Yousef Azimi; Mohammad Talaeian Araghi
Abstract
Introduction: The process of extracting and exploiting oil and gas resources requires a cycle of production, delivery, and recycling of drilling mud or drilling fluid to achieve the right composition of drilling mud and recycling it as a fundamental issue in the oil industry and also, the environment. ...
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Introduction: The process of extracting and exploiting oil and gas resources requires a cycle of production, delivery, and recycling of drilling mud or drilling fluid to achieve the right composition of drilling mud and recycling it as a fundamental issue in the oil industry and also, the environment. For this purpose, waste management methods are usually used. Material and methods: In this study, an alternative method was chosen instead of the conventional method of stabilization/solidification as a drilling waste management process that is environmentally and economically viable. A total of 80 samples were taken from four types of samples taken from nine levels in an oil well in the south Azadegan field, including mud-cutting mixture, washed cutting, fixed mud-cutting mixture by cement (1:12 portion), and fixed mud-cutting mixture by cement and silica (1:12 and 1:400 portion). Results and discussion: Samples were prepared in different types of washed, with drilling fluid, stabilized, with cement, and stabilized with cement and sodium silicate to assess the concentration of heavy metals and polycyclic aromatic hydrocarbons (PAHs), as well as the salinity. The concentration of heavy metals in the samples showed that no waste management process is required to control or reduce the metals in the samples, but salinity and PAHs require treatment at a depth of 1800 m and more. Conclusion: Summarizing the results of the analyzes showed that the washing process is better from the environmental point of view than the conventional method of stabilization/solidification because the contaminants have been removed from the drill bit, which will be utilized as the final product of this process. However, in the stabilization/solidification method, the pollutants are not purified. Therefore, the washing process was able to remove the contaminant from the excavation wells, so that the washed samples were according to the standard soil of Iran until the end of the standard drilling operation.
Sara Abdollahi; HamidReza Azimzadeh; MohammadReza Ekhtesasi; Asghar Mosleh-Arani
Abstract
Introduction: Dust is one of the phenomena of atmospheric and natural disasters that poses adverse environmental effects and impacts. Due to the wide distribution of dust, this phenomenon can also change the soil and its biology trends. Typically, dust particles have a diameter of less than 100 microns, ...
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Introduction: Dust is one of the phenomena of atmospheric and natural disasters that poses adverse environmental effects and impacts. Due to the wide distribution of dust, this phenomenon can also change the soil and its biology trends. Typically, dust particles have a diameter of less than 100 microns, which can be transmitted horizontally or vertically to the ground after miles. The aim of this study was to determine the amount of dust falling and heavy metals lead and cadmium concentrations in dust samples to evaluate these elements is the urban pollution.Material and methods: In this study, samples were collected using mild sediment trap for six months.A total of 180 samples were collected. Samples were weighed accurately using a scale of 0.001 g. The analysis of samples was performed using ISO11466. The samples were extracted by the Institute of Water and Soil Research, and the concentration of heavy metals was measured by the atomic absorption spectrometry of the Analyti jena-951 model.Results and discussion: The results showed that in the winter of March and in the spring of June, the highest rate of dust was observed. The mean lead concentration in winter was 97.32 ± 5.40 mg.kg and 90.16 ± 5.93 mg.kg in spring. Also, the average cadmium concentration in winter was 37.19 ± 3.60 mg.kg and 29.62 ± 2.42 mg.kg in the spring. According to the pollution index (PI), the level of contamination of lead is high in the floor, however, according to this index, cadmium contamination in both seasons is more than the level of contamination of lead and is higher than the limit, which is the risk index The ecology of cadmium, with an average of 1673.98 and 1333.03, also confirms this and is in the hazardous area of contamination. Also, the ecological risk of lead metal in winter was 18.14 ± 1.01 and in the spring with a mean of 16.91 ± 1.11 in the low pollution class. According to the values obtained for the pollution load index (PLI), this contamination rate is Cdwinte r˃Cdspring˃Pbwinter˃Pbsprin, and both of these elements are highly polluted in the classroom.Conclusion: The results of statistical calculations and contamination levels indicate that the amount of dust pollution to lead and cadmium is higher than most of the calculated indices in the classes with high to high contamination.Therefore, these elements have been brought into the environment as a result of human activities and have less natural origin.
Mahnaz Mohammadi; Kamal Siahcheshm; Saeed Mohammad Sorouraddin
Abstract
Introduction: Oxidation of sulfide-mineralized zones during weathering, intensifies by the biological and chemical reactions and the released acidic mine drainage (AMD) mobilizes toxic and heavy elements from the parent rock and concentrates them in soil or water environment. The village of Doustbaglu ...
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Introduction: Oxidation of sulfide-mineralized zones during weathering, intensifies by the biological and chemical reactions and the released acidic mine drainage (AMD) mobilizes toxic and heavy elements from the parent rock and concentrates them in soil or water environment. The village of Doustbaglu is located in a mountainous area to the northwest of Meshgin-shahr city, has numerous farmlands overlooking the extensive alteration zones. Field studies indicate the fact that unfortunately, especially skin diseases, liver and cancer are prevalent in the area. The importance of knowledge of heavy metal enrichment in soil resources and the high potential of Doustbaglu area for the production of agricultural and horticultural crops and its direct relationship with human health reveals the necessity of conducting this study to evaluate heavy metal contamination and identify possible sources. Material and methods: In this study, total concentration and bioavailability of heavy metals including: As, Cd, Cu, Cr, Pb, Sb, Ni and Zn in 70 surface soil samples were evaluated by ICP-MS analysis. Calculation of contamination rates of soil samples using different environmental indices including modified contamination index, soil heavy metals ecological risk index, pollution load index and Nemerow’s index indicates high contamination occurrence of these elements. Results and discussion: The results of mCd index show high degree of contamination of Cu, Cr, Cd, Pb, Sb, Ni, Zn and As in most samples. High values of the ecological risk index (up to 2076/9), indicate the level of serious contamination risk of some samples. The PLI index in 10 samples showed PLI valuesConclusion: Based on the results of geo-environmental indices, all eight studied elements showed highecological risk potential and significant contamination occurrence in stream sediments and surface horizons ofthe Doustbaglu district.
keyvan Aghaei; Mona Bouryaei; Abasali Zamani
Abstract
Introduction: Alfalfa is the most important forage plant in Iran as well as Zanjan province in which it is cultivated in soils contaminated by heavy metals like cadmium(Cd). Infected leaves of these plants can threaten the health of animals and ultimately human. Heavy metals are also among the most important ...
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Introduction: Alfalfa is the most important forage plant in Iran as well as Zanjan province in which it is cultivated in soils contaminated by heavy metals like cadmium(Cd). Infected leaves of these plants can threaten the health of animals and ultimately human. Heavy metals are also among the most important and dangerous ecological contaminants because of their long maintenance and their resistance against decomposition by microorganisms and a high potential for being assimilated by plants then entering in the human food chain. Cadmium is one of the most poisonous heavy metals for plants. So in order to analysis the contamination potential of alfalfa plants which are planted in heavy metals like Cd contaminated fields in Zanjan province, a research project was performed to evaluate the rate of accumulation of Cd in alfalfa plants and its effects on some growth, nutritional biochemical and physiological traits. Material and methods: Seeds of alfalfa (Medicago sativa L.) Hamedani cultivar, were cultured in pots containing perlite and half concentrations of Hoagland’s medium in a hydroponic condition. After three weeks, plantlets with enough growth were subjected to 0(control), 25, 50 and 100 mM concentrations of cadmium nitrate treatments. Then the growth indices such as: root and shoot length, root and shoot dry weight and nutritional traits like: Cd concentration, soluble proteins and sugars and chlorophylls contents at different parts of plants and also two antioxidant enzymes activity and proline and carotenoid contents as biochemical factors were being measured. This experiment was carried out based on randomized complete block design with 4 replications in a greenhouse condition. Results and discution: Results showed that, shoot and root length and dry weight, the contents of chlorophylls a and b, soluble proteins and also the activity of catalase enzyme in treated plants were decreased at all Cd treatments. This decrease has an upward trend from 25 to 100 m Cd treatment for most of measured traits. The maximum decrease for all measured traits was observed at 100 m Cd treatment. However, the contents of carotenoids, proline, soluble sugars and the activity of peroxidase enzyme were increased in Cd treated plants. The activity of peroxidase enzyme at 100 m Cd treatment increased 1.51 and 1.97 times more than that of control plants in shoot and root respectively. The accumulated amount of Cd in roots of treated plants was much higher than that of shoots. Conclusion: Generally, it can be concluded that: contamination of alfalfa plants by Cd leads to severe decrease of its growth and nutritional indices specially its protein and chlorophyll contents. Although the negative effects of Cd have been relatively moderated in treated plants by increasing of peroxidase activity and proline and carotenoids contents however, the considerable amounts of Cd have been penetrated from root to shoot which is very harmful ecologically. Also decreasing of total soluble proteins among with increasing of soluble sugars and proline showed a considerable decrease in nutritional indices of Cd contaminated alfalfa plants. So consuming of alfalfa plants which are cultivated in Cd contaminated fields by livestock animals is not advised.
Sohrab Mazloomi; Abbas Esmaeili Sari; Nader Bahramifar
Abstract
Introduction: Particulate matters are one of the most important air pollutants in Tehran and very dangerous for human health according to the epidemiological studies. The ambient particles contain heavy metals, some of which are toxic and carcinogenic components. Therefore, in this study, the content ...
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Introduction: Particulate matters are one of the most important air pollutants in Tehran and very dangerous for human health according to the epidemiological studies. The ambient particles contain heavy metals, some of which are toxic and carcinogenic components. Therefore, in this study, the content of heavy metals in airborne particulate matters (PM4) of Tehran was measured and the related health risk was assessed. Material and methods: Sampling of PM4 was conducted every six days using Chrono PM Sampler with a 10 L/min flow rate at two residential areas including Tehranpars in the east and Ekbatan in the west of Tehran. The concentration of PM4 was calculated with Gravimetric analysis. After the preparation of the samples using the extraction solution (HCl and HNO3), the concentration of heavy metals was measured by ICP-MS. The metal richness was assessed using the enrichment factor. For health risk assessment of heavy metals in PM4, excess cancer risk was calculated. Results and discussion: At both sampling stations, the highest concentrations in all PM4 samples were related to Al and Fe due to the high abundance of these elements in the earth's crust. The results of the enrichment factor indicated that Al, Fe, Ti and Mn in PM4 had low enrichment degree and the source of these metals might mainly be the earth's crust. Ni and Cr had a high enrichment degree. In addition, Zn, Pb, Cu, Sn, As, and Cd had a very high enrichment degree and were mainly anthropogenic. The concentration of PM4 was not significantly different between the two stations in the east and west, but the comparison of the mean concentration of metals in PM4 samples between the two stations showed that the concentrations of Mn, Cu, Sn, Ni, and As at the eastern station were significantly higher than the western station. The comparison of the enrichment factor between the two sampling stations also showed that the EF values of the studied elements at the eastern station were higher than those at the western station, which could indicate a higher contribution of anthropogenic sources in the east. Among the studied elements, the highest excess cancer risk was related to Cr(VI) due to its high toxicity. The total excess cancer risk based on the average concentrations of toxic metals in PM4 was 120.1×10-6 at the eastern station and 83.1×10-6 at the western station. Conclusion: Most of heavy metals in PM4in the east and west of Tehran had mainly anthropogenic sources and were generated by human activities, especially transportation. The average concentration of heavy metals in PM4 at the east of Tehran was higher than the west, and as a result, the excess cancer risk of toxic metals in PM4 was also higher in the east. The most dangerous carcinogenic element in particulate matters of Tehran was Cr(VI), which should be taken more under consideration and its anthropogenic emission sources must be controlled.
Mohammad Mohammadian; Gholam Reza Lashkaripour; Naser Hafezi Moghadas Hafezi Moghadas; Mohammad Ghafoori
Abstract
Introduction: At present, the increase in the Earth's population has led to an increase in consumption, and an abnormal harvest of water and soil resources.MaydavoodPlain is a very fertile plain with rich water resources in the east of Khuzestan Province.In recent years, water contamination and sinkholehazards ...
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Introduction: At present, the increase in the Earth's population has led to an increase in consumption, and an abnormal harvest of water and soil resources.MaydavoodPlain is a very fertile plain with rich water resources in the east of Khuzestan Province.In recent years, water contamination and sinkholehazards have happened in this plain.To date, very few environmental studies have been carried out on this plain. Material and methods: In this study, field and laboratory studies have been used to study the environmental hazards of the Maydavood Plain. During field studies, many sinkholes around the Maydavood Plain were identified and their dimensions were measured. Samples were collectedfrom the rocks and water resources of the region. The solubility test was carried outon gypsum samplesof Gachsaran Formationusing the circulation method. By using the Geographic Information System (GIS), isopotential map of sulfate and calcium ions was prepared for the plain. The ICP-OES analysis was used to determine the amount of heavy metals in water.GISwas also used toprepare theisopotential map ofheavy metals in the Maydavood Plain. Results and discussion: According to the office studies, the MaydavoodPlain is surrounded by Asmariand Gachsaran Formation and the bedrock of this plain is Gachsaran Formation that consists of gypsum and marlstones.All of thesinkholes are formed near the Gachsaran Formation. Results of the solubility test showed that gypsums had high solubility. Base on the isopotential map of sulfate and calcium ions, the amount of these ions were more concentrated around Sarelah and Dogacheh villages than other parts of the plain due to the dissolution of Gachsaran Formation gypsum. Hydrological studies showed that during the last 15 years, the groundwater level of the Maydavood Plain has decreasedabout 5 meters. In recent years, a few sudden sinkholes were formed, especially around Sarelah and Dogacheh villages due to the high solubility of Gachsaran Formation gypsum and a decrease in groundwater level. The type of these sinkholes a is cover collapse. Hydrochemical analysis of groundwater showed that 81, 31, 44, and 100 % of deep wellshad concentrations greater than permissible valuesof arsenic, iron, manganese,and nickel, respectively.Also, concentrations of vanadium in all of the deep wells were lower than the permissible value. Base on heavy metals isopotential map, the amount of heavy metals around of South MaydavoodPlain (Sufla) and MaydavoodVasati villages were higher than other parts of the plain. The source of heavy metals in the plain was the petroleum material pollution from oil spring existing. Conclusion: By controlling the excessive pumping of groundwater and using artificial nourishment, it is possible to prevent the decrease of groundwater quality and the formation of new sinkholes in the plain. Otherwise, the new sinkhole may be formed and cause damage. High concentrations of heavy metals in groundwater can be hazardous for the health of people living in this region. To avoid this hazard, it is suggestedto providethe drinking water for the MaydavoodPlain’s populationfrom another area with a permissible value ofheavy metals.
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.
Hamidreza Pakzad; Hashem Bagheri; Farzaneh Teymouri
Volume 15, Issue 4 , January 2018, , Pages 125-140
Abstract
Introduction:
Irankuh Pb-Zn mine is located in 20 km SW of Isfahan in the Zayandehrud river drainage basin. Shale and carbonate are host rocks of the ore deposits. High concentration of Pb and Zn formed ore complex in these rocks. Weathering and erosion of the host rocks of ore deposits, waste water ...
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Introduction:
Irankuh Pb-Zn mine is located in 20 km SW of Isfahan in the Zayandehrud river drainage basin. Shale and carbonate are host rocks of the ore deposits. High concentration of Pb and Zn formed ore complex in these rocks. Weathering and erosion of the host rocks of ore deposits, waste water and waste material arising from mining have made potential for pollution of running water, ground water and agriculture soils by the heavy metals. The main objectives of this investigation were to study the total concentration of Zn, Pb, Ni,Cu, Co, Ag, and Cd in the shale deposits of the mine and physicochemical factors on their distribution and pollution.
Materials and methods:
For measuring heavy metals values, twenty samples were taken from the shale deposits. For distinguishing the shale forming minerals, thin sections were prepared and studied by polarizing microscope. The rock forming clay minerals, after preliminary treatments (heating at 550oc, ethylene glycol solvation), were detected by XRD. Organic carbon, calcium carbonate and Eh/pH of the shales were measured. Heavy metals values in the sample were measured by AAS after mineralization. Correlation coefficient of organic carbon and Mn with metals and also metals-metals were calculated. For comparison of the heavy metal concentration relative to their natural amount (in shale), enrichment factor was applied.
Results and discussion:
The dark grey to olive colored shales in the studied area consist of clay to fine silt size. Quartz, biotite, muscovite, feldspar and clay minerals are the non-opaque minerals of the shales. The clay minerals are illit (60-70%), kaolinite (9-27%) and chlorite (7-22%) respectively. Sphalerite, pyrite and galena are the main opaque minerals of the mine. The mean OC content of the shale is about 2% (0.35-5.5%) and less than 1% calcium carbonate. The pH of the samples is nearly neutral (6.8-7.8) and they have an oxidizing to nearly reducing Eh (18 to -100 v).
Conclusion:
The average concentration of heavy metals in the shales are Zn=128.05>Pb=42.55> Ni=35.24> Cu=24.18> Co=7.4> Ag=3.33> Cd=0.79 in ppm, respectively. Highly positive correlation between Ag-Pb-Cd, Cd-Zn-Pb and Co-Ni-Mn and also positive correlation between Zn with organic carbon show geochemical convenient conditions for concentration of the metals. The calculated enrichment factor has revealed extremely high enrichment for Ag and average for Cd. Other elements are depleted in the sediments. Due to relative high concentration of the metals and their extent of the shales in the study area, activation of the heavy metals in suitable conditions can be a potential source for environmental contamination in the groundwater and runoff water of the basin.
Shahram Namdjoyan; Hossein Kermanian; Ali Abolhasani Soorki; Sedigheh Modarres Tabatabaei; Nazli Elyasi
Volume 15, Issue 3 , October 2017, , Pages 109-122
Abstract
Introduction:
It was shown that the use of signaling molecules like nitric oxide donor sodium nitroprusside (SNP) can elevate phytoremediation potential of some plant species. The aim of the study is to reveal the effect of SNP on the enhancement of the phytoremediation potential and physiological responses ...
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Introduction:
It was shown that the use of signaling molecules like nitric oxide donor sodium nitroprusside (SNP) can elevate phytoremediation potential of some plant species. The aim of the study is to reveal the effect of SNP on the enhancement of the phytoremediation potential and physiological responses of zinc-stressed safflower roots.
Material and methods:
The treatments were arranged in a completely randomized design with five replicates. After 10 days, the level of oxidative markers (e.g., H2O2 and lipid peroxidation) and antioxidant compounds (e.g., glutathione, ascorbate and phytochelatins) of plants were analyzed.
Results and discussion:
SNP application alleviated Zn-induced growth inhibition of roots probably through induction of some antioxidative compounds.Application of SNP resulted in decrease in oxidative markers and the activity of SOD as compared to the plants treated with Zn only. No relationship was found between SNP supplementation and glutathione and ascorbate levels, while upon application of SNP the level of PCs increased significantly.
Conclusion:
The results suggest that the application of SNP render safflower roots more tolerant to zinc toxicity possibly through zinc chelation by the stimulation of phytochelatin production.
Heeva Elmizadeh; Saeid Farhadi; Maryam Razmi
Volume 15, Issue 1 , April 2017, , Pages 61-76
Abstract
Introduction: Parishan wetland is one of the most valuable and ecologically important ecosystems in the world which has completely dried up in recent years due to successive droughts (Dehghani, 2007). Considering that heavy metals are among the most important pollutants of the environment, their survival ...
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Introduction: Parishan wetland is one of the most valuable and ecologically important ecosystems in the world which has completely dried up in recent years due to successive droughts (Dehghani, 2007). Considering that heavy metals are among the most important pollutants of the environment, their survival time is high in sediments (Ullah et al., 2017). Also, these metals have harmful effects on aquatic ecosystems, and sediments are both a source of and a place to store these elements. Acquiring information about these metals is important (Bhuiyana et al., 2010). Materials and methods: The purpose of this study was to estimate the level of contamination of Perishan wetland sediments with the heavy metals copper, iron, manganese and zinc using the enrichment index, geochemical accumulation index, degree of contamination and the comprehensive pollution factor index. In this study, 40 sediment samples with a weight of 200 g were systematically harvested. After acid digestion and filtering to read the concentration of toxic metals liberated in each sample, an AAS atomic absorption device by the Thermo Company (UK) was used. In this study, because of the lack of any specific standard for soil contamination in our country, standards from other countries were used. The average concentration of the metals studied in the region is lower than the maximum acceptable concentration (mg / kg) for the countries of Poland, Canada and Australia.Results and discussion: The changes in pH and electrical conductivity (Ec) were calculated in the range of 2.7-9.2 and 4.2-34, respectively, and the concentration of heavy metals based on mg/kg was found in most samples including manganese (2.18-3.71), iron (3.6-4.26), zinc (2.15-8.3) and copper (5.3-8.13), respectively. The background concentration for manganese, copper, iron and zinc was 950, 50, 41000 and 75 mg/kg, respectively. The geochemical accumulation index, the pollution factor and the comprehensive pollution factorindex were all used to determine contamination levels in the area. The geochemical accumulation index was less than zero for all metals, which shows the non-contamination class of the area. In addition, the factor of contamination index for most of the samples was in the class unpolluted, and the contamination factor for all metals was less than one, so that all data were placed in the non-contaminated class. The results also showed that the elements of manganese, copper, iron and zinc have a geological and agricultural origin, while the concentration of metals in the soil was related to their natural origin.Conclusion: Finally, it can be stated that the studied area has the lowest risk of contamination with heavy metals. In fact, it can be said that the copper, iron, manganese and zinc found in this region have a geological origin and they change through the natural processes of geology and through springs in the wetland.
Mahdi Rajabi; Milad Biranvand
Volume 13, Issue 4 , January 2016, , Pages 9-16
Abstract
Dust storms often occur in arid and semiarid regions of the world and carry a huge quantity of materials; hence, they are recognized as one of the most important environmental issues on regional and international scales. This study aimed to evaluate the heavy metal content of dust-fall particles in the ...
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Dust storms often occur in arid and semiarid regions of the world and carry a huge quantity of materials; hence, they are recognized as one of the most important environmental issues on regional and international scales. This study aimed to evaluate the heavy metal content of dust-fall particles in the cities of Sanandaj, Khorramabad and Andimeshk in western Iran. Sampling the dust-fall particles was conducted every 10 days from 20 June 2012 over one year simultaneously in these three stations using the Deposit Gauge Method and the concentration of metals was measured using Flame Atomic Absorption Spectroscopy for Fe and Mn and Furnace Atomic Absorption Spectroscopy for Zn, Cu, As, Ag, Pb, Cd, Cr, Ni . Pollution levels for the heavy metals were then evaluated using the Geo-Accumulation Index (Igeo) and Index Enrichment Factor (EF). The results obtained for the Igeo index and EF index demonstrated that levels of Ag and Cu pollution among the dust-fall particles from the three stations were higher than for other heavy metals, while concentrations of other heavy metals were not evaluated as contaminant. Although the mean of dust-fall particles on area unit in Sanandaj station was less than Khorramabad and Andimeshk, heavy metal concentrations among the sampled dust-fall particles was relatively higher. The highest amount of dust falling on a unit area was obtained from Andimesh station, more than at the Khorramabad station and, lastly, the Sanandaj station. Moreover, the maximum and minimum levels of dustfall descending on the three stations were obtained in May and January respectively.
Hamed Arfania; Farrokh Asadzadeh
Volume 13, Issue 3 , October 2015, , Pages 1-10
Abstract
The kinetics of release of heavy metal ions zinc, lead, nickel, copper and cadmium from the depth of 0 to 10 cm of downstream river sediment located in Hamedan Province, polluted with nitrate salt of these metals, were studied using the leaching column method. The rate of desorption of heavy metals from ...
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The kinetics of release of heavy metal ions zinc, lead, nickel, copper and cadmium from the depth of 0 to 10 cm of downstream river sediment located in Hamedan Province, polluted with nitrate salt of these metals, were studied using the leaching column method. The rate of desorption of heavy metals from polluted sediments was initially rapid and, then, gradually declined over time; the behavior of Pb was different and it was released in a gradual and continuous manner. In general, the release of heavy metals from clayey sediments polluted by an inorganic source conformed to a two-site model of first order kinetics; however, the release of Zn, Cd and Pb from sediment (1) and Pb from sediment (2) could also be adequately accounted for by a single-site model. The average coefficients of determination and RMSE for metals in the first order kinetics were 0.905 and 0.054 for a single-site model and for a two-site model were 0.986 and 0.046, respectively. Considering the total heavy metal content of sediments, the cumulative quantity of leached metals was low, indicating a high retention capacity of the sediments for heavy metals. This statement can be elucidated by the low values of the apparent coefficient of desorption in the first order kinetics model.
Leila Tabrizi; Siavash Mohammadi; Mojtaba Delshad; Babak Moteshare Zadeh
Volume 13, Issue 2 , July 2015, , Pages 37-48
Abstract
Rosemary (Rosmarinus officinalis L., Lamiaceae) is a perennial medicinal plant used in pharmaceutical, cosmetic, food, and beverage industries. In order to study growth and yield of this plant in symbiosis with arbuscular mycorrhizal fungi under Pb and Cd stress, a twofactored pot experiment was carried ...
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Rosemary (Rosmarinus officinalis L., Lamiaceae) is a perennial medicinal plant used in pharmaceutical, cosmetic, food, and beverage industries. In order to study growth and yield of this plant in symbiosis with arbuscular mycorrhizal fungi under Pb and Cd stress, a twofactored pot experiment was carried out based on a randomized complete block design with 4 replications in greenhouse of Department of Horticultural Sciences, University of Tehran, Karaj, Iran in 2011- 2012. The first factor was arbuscular mycorrhiza (inoculation and noninoculation), and the second factor was heavy metal contamination as listed here per mg/kg of soil: Without contamination, Pb 150, Pb 300, Cd 40, and Cd 80. The parameters plant height, number of lateral branches per plant, length of lateral stem, number of leaves, leaf area, crown diameter, shoot fresh and dry weights, leaf dry weight, leaf dry weight/shoot dry weight ratio, and essential oil content and yield were measured. The results showed that growth and yield of rosemary diminished with increasing concentration of the heavy metals in the medium; however, mycorrhizal inoculation donated a tolerance to the heavy metal stress, thereby improving growth and yield of rosemary in such a stressful situation. The highest fresh and dry weights were observed in mycorrhizal plants grown in non-pollution medium, whereas non-mycorrhizal plants grown under Cd 80 had the worst values, which were decreased respectively by 57.6% and 79.5% as compared to those of mycorrhizal plants grown on non-polluted medium. Moreover, the highest content of essential oil was recorded in non-mycorrhizal plants grown under Pb 300; nevertheless, the highest essential oil yield was found in mycorrhizal plants grown on noncontaminated medium.
Mitra Cheraghi; Alireza Safahieh; Ali Dadolahi Sohrab; Kamal Ghanemi; Abdol Majid Doraghi
Volume 11, Issue 4 , January 2014
Abstract
A. marina from aquatic plants is widely distributed throughout Bardestan estuary (Bushehr, Iran). This study examined the uptake of some metals by A. marina and their translocation from the roots to other parts of the plant.For this purpose, samples of sediment, and mangrove roots and leaves were taken ...
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A. marina from aquatic plants is widely distributed throughout Bardestan estuary (Bushehr, Iran). This study examined the uptake of some metals by A. marina and their translocation from the roots to other parts of the plant.For this purpose, samples of sediment, and mangrove roots and leaves were taken from the Bardestan mangrove. Samples were dried in the laboratory and digested in concentrated acids and their metal content was measured using Atomic Absorption Spectrophotometry. The enrichment coefficients in leaves of A. marina were smaller than 1.0 for all the studied metals. Similarly, theenrichment coefficients of all the metals (Zn, Ni, Cu, Pb, Cd), in roots of A. marina were smaller than 1.0. This study demonstrated that A. marinabehaves as an excluder plantand could be considered as either a bio-indicator or a bio-accumulator in sediments and waters polluted by heavy metals.
Mahmood Khoramivafa; Zahra Ahmadpour; Saeede Jalali Honarmand; Kianoush Choghamirza; Masoomeh Khanahmadi
Volume 11, Issue 3 , October 2013
Abstract
Two RCD factorial experiments were carried out to evaluate the ability of two aquatic plants including watercress and pennyroyal to biosorption of lead and cadmium from polluted water in hydroponic conditions. First factor was plant species (watercress and pennyroyal) and second factor was consist of ...
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Two RCD factorial experiments were carried out to evaluate the ability of two aquatic plants including watercress and pennyroyal to biosorption of lead and cadmium from polluted water in hydroponic conditions. First factor was plant species (watercress and pennyroyal) and second factor was consist of lead (50, 100, 150 mg/L) and cadmium (3, 6, 9 mg/L) in first and second experiment respectively. Root and shoot of both plants dried in an electric oven at 48hrs and 50 ○C after 14 days. 0.2 gr of plant powdered samples used for assessment of lead and cadmium accumulation by atomic absorption The highest lead accumulation in roots of pennyroyal and watercress was obtained by concentrations of 150 and 100 mg/L in (185348 and 3261 mg/kg dry weight respectively). The highest lead accumulation in pennyroyal and watercress shoots was 295.5 and 201.5 mg/kg respectively. Low translocation factors in both plants (lead 0.06 and 0.002 respectively and cadmium 0.4 and 0.004 respectively) mean less transport of metal to shoots and more accumulation of them in root consequently. There is a privilege characteristic because harvest of aquatic plants and root/shoot separation is easy.
Reza Bashiri Khuzestani; Bubak Souri
Volume 11, Issue 2 , July 2013
Abstract
Emission of dust-fall particles in western Iran has been considered as one of the most important environmental issues in recent years. Additionally, presence of heavy metal in these particles due to their toxicity and health problems has been an issue of interest by researches. Therefore evaluation of ...
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Emission of dust-fall particles in western Iran has been considered as one of the most important environmental issues in recent years. Additionally, presence of heavy metal in these particles due to their toxicity and health problems has been an issue of interest by researches. Therefore evaluation of the contamination level of this kind of pollution and then determination of proper management strategies for controlling their emission is very important. In fact, the main scope of this research was to evaluate the contamination level of heavy metals in dust-fall particulates precipitated in western Iran using Geo-accumulation index (Igeo). In this research these particles were sampled through passive deposit gauge method for a period of one year, from April 2010 to March 2011, in Sanandaj city, western Iran, where has been reportedly the third highly polluted city of the world in 2010 for dust-fall particles. The results demonstrated that mean ± SD of the concentration of heavy metals were 14003.570±915.3 for Fe, 497.731±29.817 for Mn, 61.307±5.414 for Cu and 18.287±1.955 for As in mg/Kg based on dry weights of dustfall particles. Also the analysis of the Geo-accumulation index showed that the maximum amounts of Igeo values were -1.751 for Fe, -0.63 for Mn, 0.848 for Cu and 1.249 for As, which were evaluated as uncontaminated for Fe and Mn and moderate contamination Cu and As.
