Showing 9 results for Rastegar
َahmad Joneidi Jafari, Ayooob Rastegar, Mahdi Farzadkia, Roshanak Rezaee Kalantary, Zahra Rezaee Gozalabad,
Volume 6, Issue 4 (3-2014)
Abstract
Background and Objective:Application of compost containing heavy metals can increase the concentration of metals in soil and groundwater. Therefore,the aim of this study was to investigate leaching lead, chromium,and cadmium from three soils (a sandy loam, a sandy clay loam and silt clay loam) amended with compost from the municipal solid waste. Material andMethod:First, the selected soils were repacked into columns (with an inner diameter of 100mm and a height of 600mm). Treatments included(a) low metal content compost (LMCC), (b) enriched metal content compost (EMCC) and (c) control. Then soil columns were incubated at room temperature for 9 days and were irrigated daily with deionized water to make a total of a 250 mm. Leachates were collected and analyzed for pH, EC, Pb, Cr, and Cd concentration. Results: It was found that the application ofEMCCwas significant (p≤0/05) on reducing pH, increasing electrical conductivity and leakage of metalscompared withcontrolin all three soils. But application of LMCC was not significant (p≥0/05) on the metals leaching compared withcontrolin all three soils. The overall quantities of metals leached followed the sandy loam> sandy clay loam> silt clay loam. Conclusion: The concentration of metals in the leachates depended on the soil characteristics and on the type of compost added to the soil. Therefore,application of enriched metal content compost on the soils containinga high percentage ofsandmay pose a risk in terms of groundwater contamination with heavy metals.
M Rastegari, M Saeedi, A Mollahosseini,
Volume 8, Issue 2 (8-2015)
Abstract
Background & Objectives: Polycyclic aromatic hydrocarbons (PAHs) are considered as important organic contaminants due to their high toxicity and carcinogenic properties. Among PAHs, phenanthrene is found in most contaminated sites. Sorption and desorption of phenanthrene in soil affect the fate of the contaminant in soil-water system. Presence of organic matter (OM) in the soil matrix can also affect sorption and desorption of phenantherene. In this research, effect of soil organic matter on sorption of phenanthrene in kaolin soil was studied. Materials & Methods: The sorption of sorption of phenanthrene in kaolin clay was assessed in the presence and absence of organic matter. These two soil types were used in batch sorption experiments of Phenanthrene to determine the sorption properties. Results: It was found that organic matter increases the cation exchange capacity, water content, and pH of the soil. Sorption of phenantherene in both kaolin and OM-added kaolin was better fitted with Freundlich linear model. Moreover. soil organic matter increased phenanthrene sorption in soil. Conclusion: It was observed that with 41.04% increase in OM, distribution coefficient of phenanthrene sorption in soil increased by 36.69%.
A Jonidi Jafari, F Ghorbannezhad, A Rastegar,
Volume 12, Issue 2 (9-2019)
Abstract
Background and Objective: Humans are always exposed to ionizing radiation that could potentially have harmful effects. The aim of this study was to evaluate the background gamma dose rate, the estimated annual effective dose, and the excess cancer risk assessment in Dargaz.
Materials and Methods: This study was a cross sectional study which was conducted in January- March and July – September 2016. In this study, 5 stations (4 in the main geographical directions and 1 in the center city) were selected based on the map of the city to determine the dose rate of background gamma radiation in outdoor areas. A dosimeter was used (Geiger Müller detector STEP OD-02 with sensitivity of 0-2000 mSv/h) to measure gamma rays. The device was designed to monitore X-rays, gamma rays and beta rays.
Results: The results showed that the maximum and minimum mean values of background gamma dose rate were 147±12 nSv/h and 113±11 nSv/h in the center and west-direction of the city, respectively. The annual effective dose for Dargaz residents in outdoor was determined to be 0/15 mSv/yr, and the amount of excess lifetime cancer risk was estimated as 0.6×10-3.
Conclusion: The results indicated that there are significant differences between the rates dose in the center and other parts of the city (p≤0.05).
Omid Lahijani, Meisam Rastegari Mehr, Ata Shakeri, Mina Yeganeh Far,
Volume 13, Issue 1 (4-2020)
Abstract
Background and Objective: Heavy metals contamination, particularly in aquatic environments, is an important concern. Since Mahbad river is the source for supplying drinking water to the city and the dam established on it is used for catching fish and sale in the market, heavy metals concentrations in the sediments of Mahabad River and the Dam, and the possible health risk of the fish consumption were investigated.
Materials and Methods: Sediment samples from 21 sites in Mahabad dam, and river, and 16 fish samples (Sander lucioperca and bramis brama species) were collected. After preparation, the samples were analyzed using ICP-MS method. For data analysis, enrichment factor (EF), potential ecological risk index (RI), health risk indices, principal component analysis (PCA) and Mann-Whitney test were used.
Results: The EF and RI values of the studied heavy metals in the sediments were low. The max concentrations of lead, zinc, copper, arsenic and manganese were 36, 162, 74, 22.8 and 3221 mg/kg, respectively. This was more obvious in the samples taken from the downstream of the dam. However, accumulation of the heavy metals in fish tissues resulted in high values for total hazard quotients (THQ), particularly for As (1.19); high hazard index (above 1); and high estimated daily intake (EDI) for copper (1.64) in the study area.
Conclusion: The results of this study revealed that the conditions for elements’ mobility and bioavailability was suitable in the river and Mahabad Dam. Therefore, assessing the mobility and bioavailability of the heavy metals in the sediments of the region, and measurement and continuous monitoring of the heavy metals concentrations in the water, sediment and fish of the study area are needed.
Mina Yeganeh Far, Ata Shakeri, Meisam Rastegari Mehr, Omid Lahijani,
Volume 13, Issue 1 (4-2020)
Abstract
Background and Objective: Microplastics (MPs) pollution are considered as a major growing global environmental problem in the past few decades. Dams could be an important reservoir for microplastics accumulation, therefore, in this study the presence of microplastics in sediments of Taleqan Dam and its upstream river was investigated in order to: 1) determine the local status of microplastic pollution and 2) determine the abundance and characteristics of the identified microplastics.
Materials and Methods: Sediment sampling was performed at 15 stations in the upstream of the river and the dam reservoir. After the sample preparation, separation method based on density difference was used for separation of the microplastics from the sediment, and stereo microscope and SEM-EDX were used for counting microplastics and investigation of their characteristics.
Results: Based on the results, maximum of the counted microplastic particles were observed in Taleqan City area with 2050 particles/300 g and minimum number was observed in the dam reservoir with 478 particles/300 g of sediment. The dominant shape, color, and size of the counted particles were polyhedral, colorless (transparent), and 100-250 μm, respectively.
Conclusion: The results showed that the concentration of microplastics in the stations near the urban and rural areas were higher due to the entry of sewage and the release of municipal solid wastes. Also, their concentrations were high in the stations close to the dock area of the dam due to the greater traffic of the locals and tourists and dumping of wastes in the shoreline of the lake.
Samane Zeraatkari, Ata Shakeri, Meisam Rastegari Mehr,
Volume 14, Issue 1 (5-2021)
Abstract
Background and Objective: Due to the importance of Mordab river, the concentration and distribution of heavy metals in sediments and part of Caspian sea coast, mostly affected by the Mordab river, were evaluated. Additionally, considering the possibility of heavy metals release from sediments to water column and transfer to crops, the health risk of rice consumption in the region was assessed.
Materials and Methods: 21 sediments samples and 4 rice samples from paddy fields along the Mordab River were collected. Heavy metal contents of the samples were measured using ICP-MS. Data analysis was performed using enrichment factor (EF), ecological risk index (RI), health risk index, principal component analysis (PCA) and Mann-Whitney test.
Results: The maximum concentrations of elements was higher in coastal sediments than the Mordab River. The results showed low to moderate risk of elements in most stations except for two coastal stations which exhibited considerable risk of contamination with regard to Cr. Principal component analysis categorized the elements into three components of different origin. Moreover, the estimation of weekly intake of elements through rice consumption were less than their permissible concentration set by World Health Organization.
Conclusion: The concentration of chromium in sediments, especially coastal sediments, is high, which may be partly due to the concentration of heavy minerals (chromium) in this fraction. Therefore, the origin of elements, particularly chromium, should be determined through sequential extraction methods. On the other hand, despite the pollution of river sediments and high consumption of rice among the residents of the study area, there is no danger to rice consumers in terms of heavy metals.
Fateme Rezaee, Meisam Rastegari Mehr, Ata Shakeri,
Volume 16, Issue 3 (12-2023)
Abstract
Background and Objective: Water resources deficiency has caused the use of effluents to be considered as a source for re-use in the form of haloculture projects. An attempt has been made to investigate the possibility of using effluent produced by sugarcane production companies in the implementation of haloculture projects, from the viewpoint of the most used pesticides.
Materials and Methods: Ten water, four sediment, two plant, and two fish samples were analyzed using gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) to determine the concentration of pesticides. In order to assess the ecological risk, toxic unit (TU) and risk quotient (RQ) were calculated.
Results: Glyphosate and Ametryn in all liquid, solid, and biological samples had concentrations below the detection limit. 2.4.D, Metribuzin, and Atrazine had detectable concentrations in the samples. However, their concentrations are lower than the standard values. Metribuzin and Atrazine had high concentrations in the stems and leaves of reeds in the region, which may indicate the role of these plants in the remediation of water and sediment from these compounds.
Conclusion: Using effluent from Amirkabir and Mirzakouchak Khan agro-industrial complexes to implement the haloculture project does not pose a particular problem from the viewpoint of contamination with the studied pesticides. This is confirmed due to the small concentrations of the studied compounds in the liver and below the detection limit in the muscles. However, it is necessary to carry out more studies to evaluate the quality of effluent in terms of the other types of pollution.
Majid Hashemi, Mohammad Javad Agah, Amir Mahmoud Rastegar,
Volume 17, Issue 1 (6-2024)
Abstract
Background and Objective: Paying attention to antibiotic residues in milk is important due to its health effects on the occurrence of microbial resistance in consumers, as well as its harmful effects on the dairy industry. This study was carried out with the aim of determining the amount of oxytetracycline, enrofloxacin, and penicillin G in raw milk samples produced in Fars province, which were detected as contaminated during screening with a rapid kit.
Materials and Methods: The samples were first examined with a rapid commercial kit for the presence of antibiotic residues. Then the amount of oxytetracycline, enrofloxacin and penicillin G antibiotics in the positive samples belonging to the middle month of each season was determined using the liquid chromatography-tandem mass spectrometry method.
Results: Antibiotic residues were found in 121 (7.7%) samples by the commercial Eclipse kit. Both season (p<0.001) and region (p<0.01) of sampling had a significant effect on antibiotic residues in raw milk. In the chromatographic method, antibiotic residues of oxytetracycline and enrofloxacin were detected in 6 (27.3%) samples, none of which exceeded the permissible limit determined by the Iranian Veterinary Organization.
Conclusion: Although the amount of antibiotics detected from raw milk from Fars province was much lower than the permissible limit, it is necessary to implement further executive, educational, and research measures to minimize these residues in raw milk due to the possibility of the presence of other antimicrobial substances.
Fariba Asghari, Ayoob Rastegar, Mohammad Hossien Saghi,
Volume 17, Issue 4 (3-2025)
Abstract
Background and Objective: Composting is a sustainable solution for recycling organic solid waste (OSW). Various compounds can be used to enhance the quality of compost. This study aimed to investigate the effects of zeolite on the physical and chemical characteristics of compost produced through the anaerobic process.
Materials and Methods: This analytical study was conducted in 1402 at Kimia Sabzevar Company, located 5 km from Rudab Road. Cow manure and natural clinoptilolite zeolite were used in varying proportions (0%, 5%, 10%, 15%, and 20% of the total reactor volume) to prepare fertilizer via the anaerobic method. After 30, 45, and 60 days, a total of 90 samples were collected and sent to the laboratory for analysis. Parameters such as pH, electrical conductivity, temperature, carbon-to-nitrogen ratio, and nitrate content were measured to evaluate the quality of the fertilizer product.
Results: The results showed that in the early stages, pH changes were less pronounced in treatments with varying zeolite percentages, ranging from 7.9 to 8.57. The addition of zeolite in the composting process influenced temperature dynamics, with higher zeolite percentages maintaining elevated temperatures. Moreover, the nitrate content increased by 15% during the process.
Conclusion: The findings indicate that adding zeolite to fertilizer enhances temperature stability, accelerates the composting process, and reduces the time required for fertilization. Additionally, zeolite improved the physicochemical properties of the fertilizer produced through the anaerobic process.
