Showing 13 results for Sediment
Z Bagheri, Ar Riyahi Bakhtiari,
Volume 7, Issue 1 (7-2014)
Abstract
Background and Objectives: The present study was designed to determine total mercury concentrations in sediment and the soft tissues of two bivalve species, Saccostrea cucullata and Callista umbonella, in coastline of Bandar Abbas in 2011. Materials and Methods: Generally, 67 bivalves and 10 sediment samples were collected from two stations (terminal of Bandar Abbas and tourism park of Soro). We measured total mercury concentrations in each sample using Mercury Analyzer (Leco AMA 254). Results: Means of mercury concentration were 145.58 and 151.13 (ng/g dw) in soft tissues of oyster S. cucullata and 34.5 and 63.95 in the soft tissues of Clam C. umbonella in two stations, terminal of Bandar Abbas and tourism park of Soro respectively. Total mercury concentrations were 30.27 and 20.55 (ng /g dw) in the sediment samples in two stations, terminal of Bandar Abbas and tourism park of Soro respectively. A significant difference was found in mercury concentrations between soft tissue of the two species (p <0.01). Conclusion: Considering higher concentration of mercury in the soft tissues of oyster S. cucullata than clam C. umbonella, lower coefficient of variation in soft tissue of oyster relative to clam C. umbonella, and also significant correlations between mercury levels in the soft tissue of oyster and sediments, it can be concluded that the soft tissues of oyster S. cucullata can be used as biomonitoring agent for mercury in intertidal zone of Bandar Abbas. In comparison with food safety standards (FDA, EU Commission and NHMRC), mercury concentrations in oysters were well within the permissible limits for human consumption.
Rokhsareh Azimi Yancheshmeh, Ali Reza Riyahi Bakhtiari, Samar Mortazavi,
Volume 7, Issue 2 (10-2014)
Abstract
Background & Objectives: In recent years, enterance of oil contaminants especially polycyclic aromatic hydrocarbons (PAHs) to Anzali Wetland, has seriously threatened organisms life. Therefore, the current study was conducted to determine and compare concentration of PAH compounds with multiple sediment quality assessment indice to evaluate the ecological toxicity of surface sediments of Anzali Wetland and present appropriate management strategy. Materials & Methods: We randomly collected 22 surface sediment samples each sample was dried and extracted based on the soxhlet method. Then during two-step of column chromatography the PAH compounds were separated and analyzed by gas chromatography equipped with a mass spectrometry detector (GC-MS). Results: Total concentrations of these compounds ranged from 212 to 2674 ng g-1 d.w. with the mean of 907 ng g-1 d.w. The highest concentrations of PAHs was reported from stations (3-1 and 4-1) located in the vicinity of urban areas with shipping activities. In comparison with sediment quality guidelines (SQGs) used in this study, the concentrations of most PAH compounds in the majority of stations situated in low range values of adverse biological effects. Only in a few stations (3-1, 3-2 and 5-3), the concentrations of some of PAH compounds exceeded the low range of adverse biological effects. Conclusion: In comparison with sediment quality guidelines (SQGs) used in this study, the concentrations of most PAH compounds in Anzali Wetland rarely lead to adverse biological effects. However, concentrations of some of these compounds can cause acute toxic effects. Therefore, further studies including toxicity and bioaccumulation tests and survey of benthic community composition, especially in areas exceeded SQGs are essential for proper management.
A.a Babaei, Z Nazari, E Ahmadpour, M Hosseinzadeh,
Volume 7, Issue 4 (1-2015)
Abstract
Background and Objectives: alkylphenol poly ethoxylates (APnEOs) and their metabolites enter environment through discharging wastewater and are of particular concern due to their persistence, toxicity to aquatic organisms, and a potential endocrine disruptor. In this work, we focused on the determination of nonylphenol (NP) and nonylphenol polyethoxylate (NPnEOs) in sediment samples collected from Karun River, Khoozestan Plain, Iran. Materials and Methods: Sample collection of Karun River sediment was carried out on rainy and dry seasons from 10 hydrometric stations. The sediment samples were prepared and extracted using solid phase extraction procedure and were analyzed using HPLC-FLD. Results: We found that NP and NPnEOs concentrations in sediment samples of Karun River were 0.21-2.43 and 0.18-0.91 µg/g respectively. This study revealed that NP concentration in sediment samples of Karun River was higher than the other alkyphenolic metabolites. Conclusion: The results indicated accumulation of endocrine disrupting contaminants (EDCs) in the Karun river sediments. The results showed significant difference between mean concentrations of these compounds in the upstream and downstream stations of Ahwaz Megacity (p-value<0.05).
M Zamani, N Khorasani, A.r Riahi Bakhtiari, K Rezaei,
Volume 7, Issue 4 (1-2015)
Abstract
Background and Objectives: This study was performed to determine and identify the origin, concentration and source of perylene entry and some PAH compounds in surface sediments of Ghalam Goodeh (A), Siyah Kashim (B), and Talab Markazi (C) in Anzali wetland. Materials and methods: We collected 22 samples of sediments (from each region) and 2 samples of soils (from A region) in April of 2012. Sampling was performed from soil for proving the condition of concentration and origin of perylene in under investigating sediments. GC-MS was applied for extraction of PAH compounds using organic solvents and 2-phase column chromatography. Diagnostic ratios of Ph/An, Flu/Pyr, Flu/Flu+Pyr, BaA/BaA+Chr and IP/IP+BghiP were used to determine the origin of PAH compounds. Results: In all sediment samples, the origin of perylene and PAH compounds were found to be natural and petrogenic, respectively. The total concentration of PAH compounds were ranged between 560.05 to 1051.93 ng/g dry weight and perylene concentration were obtained between 70.65 to 204.41 ng/g dry weight. Total concentration of PAHs and perylene was significantly more in area A compared with other two area, whereas no relationship was found between normalized values of PAHs and TOC in sediments of all areas. Conclusion: With respect to the petrogenic source of PAHs in the surface sediments, the main sources of the PAH compounds entry are the discharge of domestic and industrials wastewater, the port and shipping activities, the exploration, excavation and refining activities of crude oil in offshore region and transportation of fishing and tourism boat but diagnosis of natural origin of perylene in the samples of surface sediment and soil implicated that this compound can be produced in terrestrial section due to activity of termites and fungi on the woody and cellulosic materials of forest floor, decaying wood and their fossilized remains and then their discharge to the wetland.
A Bazzi,
Volume 8, Issue 1 (8-2015)
Abstract
Background & Objectives: This paper, discussed the concentrations of heavy metals such as cadmium, copper, lead, zinc, nickel, chromium, iron, and magnesium in surface sediments of the Gulf of Chabahar. Materials & Methods: Samples of coastal sediment and shallow waters were collected from five different stations in summer and winter, 2013. Results: The research found that the concentrations of heavy metals in sediments is more than water, although the concentrations of metals in sediment and water from different stations followed a general trend. Seasonal variation had effect on the concentration of metals, so that in winter, the concentration of heavy metals such as copper, lead, zinc, cadmium, and nickel was more than of the summer season. Conclusion: Generally, concentration of heavy metals in the study area was less than the quality guidelines for sediments and water. However, between different stations, higher concentrations of heavy metals were found in stations nearby the fishing ports. The results show that increase in the concentrations of heavy metals can contribute considerable impacts on the pollution level due to fishing boats in the study area although some metals are also of natural origin.
S Alidoust, N Bahramifar, A Esmaeli Sari,
Volume 10, Issue 1 (6-2017)
Abstract
Background and Objective: Mercury (Hg) is considered as a global pollutant that is widely dispersed in the environment. Monitoring of total mercury (THg) concentration in the sediments without determination of organic mercury (OHg) and selenium (Se) is an unreliable approach to evaluate the precise toxicological effects of Hg. In the present study, concentrations of THg, OHg and Se in the surface sediments of the eastern and western parts of Anzali wetland were investigated. In addition, the correlation of THg and OHg with Se and total organic carbon were analyzed.
Materials and Methods: Forty surface sediment samples were collected from the eastern and western parts of the wetland. Analysis of total and organic mercury in the sediment samples were done with Advanced Mercury Analyzer and the concentration of selenium was measured using inductively coupled plasma atomic emission spectroscopy (ICP-OES).
Results: The average concentrations of THg in the East and West wetlands were 109.53 and 68.39 ng/g dw, respectively. The average concentration of THg in the sediments of the eastern part of Anzali Wetland was significantly higher than that of the western part (P<0.001). The mean concentrations of OHg in East and West wetland were about 34.91 and 28.84 ng/g dw, respectively. There was no significant relationship. The ratio of OHg to THg showed significant differences in the two studied areas. The average concentrations of Se in East and West wetlands were 156.25 and 163.75 ng/g dw, respectively. There was a significant negative correlation between the concentration of selenium and organic mercury in sediments of the western part of wetland (P<0.05).
Conclusion: The THg concentration in the sediments of Anzali wetland was lower in comparison to other studied regions of the world. However, the percentage of OHg in the Eastern and Western part of wetland was high. Therefore, bioavailability and toxicity of Hg would be high in the sediments and aquatic environment. In this study, in spite of high molar ratio of Se to THg, there was relatively high content of OHg. We recommend to measure the various Se-species that are effectively bound to inorganic Hg and to determine the amount of Se and Hg in aquatic organisms.
H Malvandi, N Hassanzadeh,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: Heavy metals contaminations are readily bioaccumulated in aquatic systems and lead to increased concentrations in food chains, posing a serious threat to human health, water-related organisms and aquatic ecosystems. The purpose of the present study was to determine the concentration of heavy metals in surface sediments of CheshmehKile River, to evaluate environmental and ecological risk and to determine the degree of contamination of the elements studied.
Materials and Methods: In this study, 25 samples of surface sediment were collected from the CheshmehKile River. The heavy metals content of the samples was measured by inductively coupled plasma-optical emission spectrometry. According to the content of heavy metals in sediment samples, environmental and ecological risk indices were calculated. Also, river contamination was evaluated by comparing the elements studied values with the sediment quality guidelines values.
Results: The mean concentration of chromium, manganese, iron, cobalt, nickel, zinc and arsenic were 41.27, 356.35, 16756.32, 9.17, 11.87, 41.24 and 24.60 µg/g, respectively. Based on the values of the CF and Igeo indices, all of the elements, with the exception of arsenic, showed a low degree of contamination. The indices of Eir and RI also showed the lowest ecological risk at all stations.
Conclusion: The results of this study showed that the surface sediments of CheshmeKile River in Mazandaran province were somewhat contaminated with arsenic. However, fortunately, the river sediments were of good quality from the point of view of the content of chromium, manganese, iron, cobalt, nickel and zinc.
P Nourozifard, S Mortazavi, S Asad, N Hassanzadeh,
Volume 11, Issue 3 (12-2018)
Abstract
Background and Objective: Marine sediments are the most important component of monitoring the health of aquatic ecosystems. The present study uses sediment quality indices to determine the contamination status in Qeshm ecosystems and to evaluate the toxicity of the elements studied for its organisms.
Materials and Methods: Sampling of surface sediments of seven stations was carried out on Qeshm coastal areas. The samples were digested by a combination of nitric acid and perchloric acid, and the concentration of metals was measured by atomic absorption spectrometry.
Results: The results of modified Hazard Quotient indicated a high pollution rate for copper and nickel metals in most stations, which was consistent with the results of the Potential Contamination Index in relation to nickel metal. Additionally, the results of the Potential Contamination Index and Contamination Factor agreed with the amount of lead element. According to the results, the pollution index of Hamoon Lake and Zakeri pier was highly contaminated and Modified Pollution Index demonstrated a contamination in Romacha, Hamoon Lake, Zakeri pier and Nazes areas. The enrichment factor associated with contamination regarding most of the heavy metals confirmed the indices used to evaluate the comtamination in the study area.
Conclusion: Due to the higher concentrations of the heavy metals in the sediments than that of the quality guidelines, the high toxicity of sediments for the aquatic ecosystems was confirmed. The Romachah, Hamoon, Zakeri stations showed higher pollution levels and sever toxicity for aquatic life. Copper, nickel and in some cases lead, were the main heavy metals that contaminated the sediments in the region.
F Bateni, A Mehdinia, M Seyed Hashtroudi ,
Volume 11, Issue 4 (3-2019)
Abstract
Background and Objective: This study conducted to assess ecological risk of an important group of pollutants called polycyclic aromatic hydrocarbons (PAHs) in offshore sediment of the Persian Gulf deposits in Bushehr province. The aim of this study was to model the toxicity of PAHs for aquatic organisms in the study area.
Materials and Methods: In the first step of the applied risk assessment model in this study, the unit of toxicity for each PAH and solubility were calculated by Quantitative Structure-Activity Relationships (QSAR) model. In the second step, the pore water concentration of all compounds in sediment was calculated as an available fraction. Finally, the proposed model was used to evaluate the offshore sediments of the Persian Gulf. Sediments in 19 stations and 7 transects were studied to assess the ecological risk of 21 PAHs. The extraction and clean up method was based on pressurized liquid extraction (PLE) with packed clean up cell. Compounds were analyzed by GC-MS.
Results: The toxicity and solubility of PAHs were modeled. The Pearson correlation for the predicted and measured data was more than 0.93. The amount of total toxicity was introduced as a risk index. The maximum and minimum total toxicity values for the sediments were found as 0.018 and 0.147, respectively. The results from this study indicated that although the concentration of PAHs in the sediments may not cause significant concern in the study area, they may affect benthic organism at the sub-lethal levels. According to the applied risk assessment model for 21 unsubstituted PAHs, the offshore sediments of Bushehr are in low-risk range.
Conclusion: The result of this study indicated a low risk of the sediments. The hazard index decreased as the distance from coastal and oil and gas industry increased, indicating the high impact of anthropogenic activities on the contamination of the study area.
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.
Arezoo Khalijian, Bahareh Lorestani, Soheil Sobhanardakani, Mehrdad Cheraghi, Lima Tayebi,
Volume 14, Issue 4 (3-2022)
Abstract
Background and Objective: Soils and sediments contamination with trace and toxic elements lead to potential ecological risk and adverse effects on human health and so have been the cause of increasing concern worldwide. Therefore, this study was carried out to potential ecological risk assessment of As, Cd, Ni and V in surface sediments of Khazar Abad, southern parts of Caspian Sea in 2019.
Materials and Methods: In this descriptive cross-sectional study, a total of 36 surface sediment samples were collected from 12 sampling sites. After samples preparation, the elemental contents were determined using ICP-OES. Also, potential ecological risk factor (Eir) and cumulative potential ecological risk index (RI) were calculated. All statistical analyses were performed by SPSS software.
Results: Based on the results obtained, the mean contents of As, Cd, Ni and V in analyzed samples were found to be 12.7, 0.191, 35.0, and 31.9 mg/kg, respectively. The computed values of Eir showed that factor values were decreased in the order Cd > As > Ni > V. Additionally, the mean values of RI with 53.7 indicated that all the examined elements have the "low potential ecological risk".
Conclusion: Accordingly, although the examined elements have shown a low potential ecological risk, cadmium with 46.4% and arsenic with 45.4% mean values of RI can cause for concern. Therefore, source identification and management of organic and inorganic pollutants and also periodic monitoring of water and sediments as the sink of environmental pollution are recommended.
Fatemeh Kakouei Dinaki, Mehrdad Cheraghi, Bahareh Lorestani, Soheil Sobhanardakani, Atefeh Chamani,
Volume 16, Issue 3 (12-2023)
Abstract
Background and Objective: Monitoring and remediation of metal contaminants in aquatic ecosystems is of particular importance to estimate, control, and reduce the level of threats to alive creatures and humans. Therefore, this study was conducted to evaluate metal contamination of surface sediments and the ability to monitor and bioremediation of iron, lead, and copper by aerial and underground tissues of Typha Latifolia and Nasturtium microphyllum located along the aquatic ecosystem of the Lar River, Tehran, Iran in 2021.
Materials and Methods: In this descriptive study, after selecting four sampling sites, 48 plant samples and 12 sediment samples were collected. After preparation and acid digestion of the samples in the laboratory, the contents of the elements were determined using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Also, pollution index (PI), pollution load index (PLI), bioconcentration coefficient (BCF), bioaccumulation (BAF), and translocation factor (TF) were calculated. Statistical analyses of the results were performed using SPSS statistical software.
Results: The highest values of Fe, Pb, and Cu (mg/kg) in sediment samples were 11.8 ± 0.665, 0.915 ± 0.030, and 0.710 ± 0.026, respectively, and belonged to station 4; and in plant tissues 11.4 ± 1.25, 0.578 ± 0.180, and 0.298 ± 0.095, respectively, and were belonged to the roots of T. Latifolia. The PI values showed that the pollution of Fe, Pb, and Cu was "low" and the average PI values for the elements followed the descending order of Pb > Cu > Fe. The average values of PLI also vary from 0.003 to 0.006, indicating the quality conditions of "no pollution" in all the studied stations. On the other hand, T. Latifolia had a BCF > 1 and TF < 1 for Fe.
Conclusion: Based on the results obtained, it can be concluded that T. Latifolia is a suitable species for stabilizing Fe in sediments and could be used to monitor and remediate potentially toxic elements from polluted aquatic ecosystems.
