جستجوی مقالات مرتبط با کلیدواژه « heavy metals » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

Heavy metals are major soil pollutants due to their toxicity and persistence. Mining activities are a significant source of pollution in natural ecosystems. With its numerous mines, the Khaf region is a case in point. Identifying plants capable of absorbing metals from contaminated soils is crucial for phytoremediation efforts. This study investigated the phytoremediation potential of three plant species – Artemisia sieberi, Salsola richteri, and Scariola orientalis – in the iron mine area of Khaf city, Razavi Khorasan province, Iran.

All plant species were first surveyed at distances 500, 1000, and 3000 meters from the mine to determine the dominant vegetation type. Three species belonging to this dominant type were then selected for heavy metal analysis. Plant samples were collected from different parts (leaves, roots) of these dominant species, along with soil samples from around their roots, at varying distances from the mine and in the direction of the prevailing wind. A total of 36 plant and 36 soil samples were analyzed for copper, iron, and lead using inductively coupled plasma (ICP) to determine metal contamination levels. Plant remediation potential was assessed using various phytoremediation indicators.

Significant differences in phytoremediation indicators were observed among the plant species. Salsola richteri exhibited the highest bioconcentration factors (BCF) for lead (1.38), iron (1.37), and copper (1.99), and the highest bioaccumulation coefficients (BAC) for lead (1.55), iron (1.72), and copper (1.95). This indicates Salsola richteri's strong ability to accumulate these metals.The highest lead soil pollution index (2.64) was found around Artemisia sieberi, signifying moderate lead pollution exceeding natural levels in this plant's habitat. The highest iron contamination was observed in the soil around Artemisia sieberi and Scariola orientalis.

Metal concentrations in shoots, roots, and soil were highest at 500 meters from the mine and decreased with increasing distance. Soil analysis revealed higher average concentrations of the studied elements compared to global soil values. Notably, high concentrations of copper (490 mg/kg), lead (343 mg/kg), and iron (49000 mg/kg) were observed.At 500 meters from the mine, Salsola richteri displayed BCF values of 1.4, 1.5, 1.45, and 1.02 for lead, iron, copper, and BAC values of 1.7, 1.8, 1.4, and 1.34, respectively. Based on these results, Salsola richteri shows promise as a suitable plant for decontaminating soils in the Khaf mine area.

The objective of this study is to investigate the quality of water resources in Tahroud region in the northwest of Bam city, Kerman province through hydrogeochemical studies. For this purpose, 13 water samples, including 5 samples from the agricultural wells, 4 samples of Ghanats, 3 samples from springs and 1 sample of Tahroud river were sampled and analyzed in the laboratory using Inductively coupled plasma mass spectrometry (ICP-MS) method. Based on the hydrogeochemical analysis, the water resources of the studied area have dominant Na-Cl facies and are classified as saline waters. The average concentration of EC (6230 µS/cm), TDS (4050 mg/L) as well as of Clˉ (1391 mg/L), Na+ (9031 mg/L) and SO42- (771 mg/L) in the investigated water samples were remarkably higher than the normal or recommended values. The highest amount of these soluble ions were observed in the water samples collected from the playa section of the catchment basin, which was mainly covered by the Quaternary fine-grained deposits. In addition to the hot and dry climate and the high evaporation rate, the existence of Neogene formations containing gypsum and sodium salt under these sediments is another important factor that increase the solutes in underground water sources in this area. Among the investigated potentially toxic elements, the concentration of arsenic with natural origin and higher than the permissible limit of drinking water was observed in some water samples. The evaluation of the water quality of the region using the Schuler diagram also showed that these water sources have an unfavorable to unusable quality for drinking and even for agriculture in some cases.

High concentration of heavy metals in soil directly affects soil and water quality and human safety. Therefore, decreasing mobility of metals, especially in contaminated soils by cost-effective amendments can solve environmental problems. The aim of this study was to evaluate the effect of nanobiochar on the mobility of lead (Pb) and zinc (Zn) in contaminated calcareous soils. This study was carried out as a factorial experiment based on a randomized complete design with two factors including: 1) type of bioadsorbents (4 type) and rate of bioadsorbents (3 rate) for 90 days in three replications. At the end of incubation period, Pb and Zn availability and their chemical fractions were measured. The results showed that the greatest reduction in Pb and Zn availability was observed in soil treated with Fe-NB. The Pb and Zn availability in Fe-NB-1% decreased by 34.65 and 15.38% compared to the control treatment, respectively. Application of biochar, especially in nano size, significantly (P<0.05) decreased the exchangeable fraction and increased iron and manganese oxide bound and residual fractions of the metals in comparison to the control treatment. The IR Values increased and MF values decreased with increasing biochars and nanobichars levels that indicating a decrease in the mobility of metals in the soil. In general, the addition of nanobiochar in soil causes the transformation of metals from unstable form (exchangeable and carbonate forms) to stable forms (iron and manganese oxide bound and residual forms) and further reduces the mobility of metals in the soil.

Environmental pollution with heavy metals is one of the inevitable human and environmental issues and threats that human societies are facing. The present research has evaluated the pollution level of Zoshk-Abardeh catchment basin with 11 heavy elements (Arsenic, Cadmium, Cobalt, Chromium, Copper, Iron, Molibden, Nickel, Lead, Vanadium and Aluminum). In this research, indicators such as enrichment factor, contamination factor, modified contamination degree, pollution load index, Geoaccumulation index and ecological risk index were used to measure pollution. The results of the calculation of the enrichment factor and contamination factor indicate that the studied elements have no enrichment or little enrichment in the region. According to the modified contamination degree, it can be said that all values ​​are below 1.5 and are in the category of no pollution to low pollution. The pollution load index also shows that the samples in the study area do not show any specific pollution. The results of the Geoaccumulation index indicate that all the studied elements in the study area have values ​​less than zero, which are in the non-polluted class. According to the coefficient of ecological risk potential, the basin has a low risk potential. The value of the ecological risk index was 87.13 that it can be said the ecological risk status of sediments in the studied area is low due to heavy elements. Considering that the study area is one of the target areas for tourism and human activities can increase the concentration of elements in sediments, protective and management planning should be done to control pollution.

While Iran’s soil is considered one of the richest soils in terms of mineral deposits worldwide, it is contaminated with heavy metals. On the other hand, some studies have recommended the use of native plants as a sustainable strategy to resolve the environmental problems caused by mining. In this regard, phytoremediation can be regarded as an economical, effective, economical, biological, and practical method for removing heavy metals from contaminated sites. Therefore, this study sought to investigate the potential of Seidlitzia Rosmarinus and Haloxylon Aphyllum desert species for the phytoremediation of heavy metals (i.e., Ni, Co, As, Cr, and V) found around the bauxite crusher of Jajarm alumina mine in the direction of the prevailing wind. 

Soil sampling was performed at distances of 450-700, 800-1200, 1400-2000, and 2500-5000 meters away from the center of the bauxite crusher and the control site. To this end, the seeds of the above-mentioned species were planted in pots with a 3:1:1 ratio of sand, dung, and soil, respectively. Then, the planted seeds were transferred, after two months, to the pots containing the soils sampled from target distances. Finally, upon the completion of the vegetative period, phytoremediation was carried out on the potential species using a factorial experiment in a greenhouse located at Gorgan University of Agricultural Sciences and Natural Resources, applying a completely randomized block design with three replications. The data analysis was then performed using the SPSS software, and Duncan's test was used to compare the obtained means for the significant results at the 5% level. To check the normality of the data, the Kolmogorov-Smirnov test. Moreover, the homogeneity of variances was checked via the Lyon test.

The results indicated that S. Rosmarinus and H. Aphyllum contained various amounts of heavy metals, with the amount of absorbed Arsenic (As), Chromium (Cr), and Cobalt (Co) being greater in aerial and underground tissues of the H. Aphyllum species than those of the S. Rosmarinus. However, the case was reversed in terms of Nickel (Ni) and Vanadium (V), that is, the number of such metals was greater in aerial and underground tissues of S. Rosmarinus tissues compared with H. Aphyllum.
 
On the other hand, while the transfer rate of As, Cr, and Co was higher in H. Aphyllum than that of S. Rosmarinus, the transfer rate of Ni and V was greater in S. Rosmarinus compared to H. Aphyllum. The results of the study also suggested that whereas the rates of Ni, As, Cr, and Co bioaccumulation factor was higher in S. Rosmarinus than those of H. Aphyllum, it was the bioaccumulation rate of Co that was greater in H. Aphyllum compared to the S. Rosmarinus.
In this regard, the average amount of Ni, Co, As, Cr, and V in H. Aphyllum were found to be 469.19, 172.74, 9.51, 21.59, and 23.07 mg/kg in the intended intervals, respectively. Moreover, the average transfer rates of such heavy metals in the species were reported as 1.09, 1.21, 1.08, 1.21, and 1.02, respectively, and the average bioaccumulation rate of metals was found to be 0.53, 0.26, 0.66, 0.50, and 0.30 mg/kg, respectively.
On the other hand, the study found that the average amount of Ni, Co, As, Cr, and Vanadium in S. Rosmarinus was 479.31, 169.34, 9.42, 21.18, and 30.85 mg/kg, respectively. Furthermore, the average rates of the transfer factor in the species were 1.20, 1.05, 1.01, 1.05, and 1.05, respectively, and the average rates of bioaccumulation were reported as 0.55, 0.24, 0.68, 0.54, and 0.39 mg/kg, respectively.
The results of the study also indicated a significant difference between the aerial and underground tissues of the intended species in terms of vanadium accumulation at a 1% significance level. Moreover, the transfer and bioaccumulation rates of Ni, Co, As, Cr, and V were greater and less than 1 in S. Rosmarinus and H. Aphyllum, respectively, indicating that the species had transferred metals to their aerial tissues. Therefore, as S. Rosmarinus and H. Aphyllum have low biochemical rates, they are appropriate for phytoextraction purposes in the phytoremediation process.

According to the results of the current study, S. Rosmarinus and H. Aphyllum are highly applicable for the extraction of Ni, Co, As, Cr, and V in the phytoremediation of the study area. On the other hand, as the intended species are indigenous to the study area, they can be planted in the area for clearance purposes. Moreover, after removing the aerial parts of S. Rosmarinus and H. Aphyllum for the preservation and clearance of the ecosystem, their remaining parts could be collected and burned under controlled conditions, using their ashes (as biological ore) for the re-extraction of metals or other economic purposes.
Therefore, the species are recommended for clearing the study area and similar areas of heavy metals. However, to conduct more comprehensive studies on the potential phytoremediation applicability of S. Rosmarinus and H. Aphyllum, it is necessary to necessary examine the species grown in pots in terms of field studies so that they can be used as a suitable model for phytoextraction and the revival of the lands contaminated with heavy metals.

Mining activities lead to the degradation of rangeland ecosystem structures and functions. Coal mining in rangelands generates substantial quantities of waste dumps, which serve as the primary environmental pollutants in the area and its surrounding ecosystems. Vegetation restoration in these mining areas can help reduce soil pollution and contribute to the overall landscape restoration. The aim of this study was to assess the physical and chemical properties of abandoned coal wastes in the rangelands of Kiasar, Mazandaran province, Iran. This information can be utilized to promote vegetation restoration on coal mine wastes by identifying the factors that limit plant growth and establishment on such substrates.

This study was conducted at the Kiasar coal mine in Sari, Mazandaran province, Iran. The mine site was established in 1983. The area is located at an elevation of 1030 m above sea level, with an average rainfall of 520 mm and a mean temperature of 13.2°C. A total of 10 coal waste dumps were abandoned in the area over the last three decades. Six age classes were identified based on the time since abandonment of these waste dumps in the surrounding area of the mine site. The identification process involved the assistance of experienced engineers and local workers. The age classes were categorized as follows: 4-6, 8-12, 15-18, 19-21, 22-24, and 25-27 years since abandonment. The control site consisted of natural rangelands around the mine, which are currently used for livestock grazing. Waste and soil samples were collected using a random-systematic method from a depth of 0-20 cm. The samples were then placed in plastic bags for subsequent chemical analysis. The soil samples were air-dried at room temperature, and various parameters, including texture, moisture, pH, EC, OC, CaCO3, N, P, K, Cu, Fe, Cd, Ni, and Pb, were measured in the laboratory. Data were analyzed using one-way ANOVA, and means were compared using Duncan multiple tests.

The analysis of variance indicated that all measured parameters of soil and coal, except nitrogen and potassium, exhibited statistically significant differences among the coal wastes and the nearby rangelands. The coal wastes had lower percentages of silt, clay, moisture, and lime compared to those in the surrounding rangelands. However, these properties did not show significant differences among the various abandoned coal wastes. Most of the abandoned wastes were characterized as neutral or alkaline, with an electrical conductivity (EC) less than 1.5 dS/m. An exception was found in the waste that was abandoned 22-24 years ago, which exhibited acidic pH

In conclusion, our study revealed that moisture availability is a crucial limiting factor for plant growth on coal wastes. This limitation can be attributed to the sandy and sandy-loamy texture, unstable slope of coal dumps, and high porosity of the substrate. Moreover, coal waste undergoing erosion and leaching exhibited high electrical conductivity (EC) and low pH levels. The levels of organic matter and available phosphorus were found to be insufficient for supporting optimal plant growth. However, the concentrations of heavy metals remained within the normal range, even after a significant period since the abandonment of coal wastes. We recommend the implementation of remediation treatments in similar restoration projects to enhance plant growth and establishment.

Potentially toxic elements (PTEs) contain two classes of essential and non-essential elements that are significant in toxicological ecology. These elements have high stability and have the ability to cause toxicity in living organisms. Phytoremediation has been considered as one of the most appropriate and efficient methods to uptake these elements. The aim of this study was to investigate the ability of different forage species to absorb PTEs and to be aware of the compatibility and resistance of each to contamination, a comparison between species with different biological conditions. This study was performed in a greenhouse environment and Dactylis glomerata, Festuca ovina and Medicago sativa species were considered. To measure PTEs (lead and cadmium), dry ash extraction method was used. Also, to determine the phytoremediation potential of plant indices TF, BCF and BAC were used. To compare the data statistically, multivariate analysis of variance test in the form of general linear model was used and for multiple comparison of means, Duncan test was used. The results showed that D. glomerata with increasing concentrations of lead (200 to 800 mg/kg) and cadmium (50 to 200 mg/kg) increased their concentration in shoots and roots by about 84% and 86%, respectively in the shoot and root. The root uptake of M. sativa increased with increasing lead concentration, and as a result, M. sativa is an extractive plant for both cadmium and lead. In Festuca ovina species, with increasing lead concentration, the rate of uptake by roots and shoots was 70% and 58%, respectively, and for cadmium was 79% and 73%, respectively. In general, in the studied species, the efficiency of phytoremediation of lead was higher in the aerial parts to the root, but cadmium of the roots of D. glomerata and F. ovina, had more phytoremediation efficiency than the aerial parts.

The present study was conducted to measure the heavy metals of Cu, Ni, Pb and Zn in sediments, roots, stems and leaves of mangrove tree (Avicennia marina) from five stations in Khamir port located in the southwest of Bandar Abbas with three replications in summer 2020. In addition, some geochemical parameters of the sediments of the bed of these mangroves such as Muller index, contamination factor and ecological risk index have been evaluated. The accumulation pattern of heavy metals in the sediment was obtained as Ni> Pb>Zn>Cu. This pattern for root, stem and leaf tissues were determined as Ni>Cu>Zn>Pb, Cu>Zn>Ni>Pb and Cu>Zn>Ni>Pb, respectively. According to the bio concentration factor, plant tissues can be a suitable bio-indicator for Cu in the region. Root can also be considered a good bio indicator for Pb and Ni metals. For Zn metal, leaf and stem tissues were also identified as suitable indicators in the region.Transfer factor was significant only for Cu and Zn metals in stem and leaf tissues, which showed a direct relationship between cu and Zn concentrations in roots and then in leaves and stems. Also, examination of metal concentrations in sediments in all stations showed that only nickel metal concentration was critical. Also, the findings of the study of environmental assessment index of heavy metals showed that the sediments of Khamir port are in the category of low ecological risk (RI<150) in terms of ecological pollution index. In general, the process of accumulation of metals in sediments and mangroves tissues showed that increasing the concentration of elements in sediments, the amount of these elements in plant tissues can also increases, so, A. marina can be a bioindicator for heavy metals in the studied ecosystem. In addition, this plant reduces the mobility and bioavailability of the studied metals in the sediments of this ecosystem.

Due to human activities, Shadgan wetland is always exposed to heavy metal pollution. The purpose of this research is to evaluate the environmental risk of Shadgan wetland caused by the entry of heavy metals lead and cadmium into the wetland. For this purpose, the water and sediment of the wetland were sampled and the concentration of metals in the water and sediment was measured by atomic absorption method and graphic furnace system using a device (Perkin Elmer 4100). The results showed that the concentration of lead and cadmium in the water was higher than the standards of the World Health Organization and the US Environmental Protection Agency (EPA). The concentration of these two metals in the lagoon sediment was lower than the standards. Using the outputs of the Ecofate model, risk assessment was done with the risk reduction (RQ) method. Based on the results, moderate risk was estimated for lead in water and in sediment, minimum risk for cadmium in water, and maximum risk for cadmium in sediments. Pearson's correlation coefficient showed a strong and significant relationship between cadmium in water and cadmium in sediment (P>0.05), so the ecological risk of the wetland caused by the accumulation of this metal in the sediments of the wetland has been brought about, so the correct environmental considerations in Shadgan wetland should always be taken into consideration.

Evaluating the metals concentration and their environmental risk for pollution monitoring is necessary to maintain the quality and the health of the ecosystem. In this study, the distribution and ecological risk assessment of heavy metals in the sediments of the estuaries around the petrochemical units were investigated. The purpose of this research is the pollution value and ecological risk assessment of heavy metals in the sediments in Shadgan wetland. A systematic method of random classification was used to determine the sampling points and 36 sediment samples were collected and transferred to the laboratory for analysis. Preparation and complete digestion of sediments were performed according to standard Mopam instructions. For analyze to of samples, was used ICP-OES model 730-ES device. Important environmental indicators such as the geochemical index (Igeo) and ecological risk index (ERi) were calculated. Based on the results obtained, mean concentrations of Ni, Pb, Hg, and V were 55.8, 8.5, 6.9 and 88.7µg/g, respectively. The research results showed that distribution pattern of heavy metals in the sediments was V>Ni>Pb>Hg. Based on Muller's geochemical index, pollution degree was severe contamination for nickel and lead, severe to very severe contamination for mercury, and moderate contamination for vanadium. The ecological risk index (ERi) analysis showed that the risk situation is considerable for Ni, Pb, and Hg and moderate for V. It can be concluded that the Shadgan wetland is contaminated with heavy metals due to the inflow of effluents from petrochemical industries. The use of modern treatment plants, decomposition of pollutants and the use of raw materials with a lower percentage of pollutants in wastewater management are necessary to reduce pollutants.

Soil contamination with heavy metals is a serious issue in all the world, and these heavy metals are released from both natural and human resources, especially agricultural activities in the environment. Therefore, in this study, the amount of heavy metals and the indicators of ecological risk potential and integrated pollution in soil samples before rice planting and after rice harvesting in Mazandaran province have been investigated. A mixture of nitric acid, hydrofluoric acid and perchloric acid was used for chemical digestion of soil samples and ICP-MS was used to measure the amount of heavy metals in soil samples. The results of comparing the levels of chromium, zinc, nickel and lead in the soil before rice planting and after rice harvesting with the national and international soil standard show that the levels of these metals in most stations are higher than Domestic and international standard limits were measured. Based on the results, the amount of ecological risk potential index in soil samples showed that in all studied stations ana sampling stages, the amount of this index was calculated in the range of low ecological risk (below 150). Also, the results of PI pollution index and integrated pollution index (IPI) for each studied station in soil samples before rice planting and after rice harvesting show the PI index for arsenic, chromium, cadmium, copper, nickel, zinc and mercury. In all stations in soil samples before rice planting and after rice harvesting in the range of low contamination was calculated, only the amount of this index for lead in all stations and sampling stages, in the range of moderate contamination was obtained. Also, the results of IPI for all studied stations in all stations and sampling stages, show that the level of this index was determined in the low pollution range. In general, the presence of heavy metals in the soil environment, followed by the accumulation of heavy metals in food, has detrimental and irreversible effects on human societies and food security, so more precautions are needed to reduce such effects.

Tea is not only known as one of the most common beverages in the world but also as a quite favorable and frequently consumed drink in Iran. Accordingly, studying the fresh tea leaves’ heavy metal content is an area of attention considering the environment quality assessment in addition to the public health issues. The research aimed at determining the concentration of heavy metals including lead, cadmium, zinc, nickel, cobalt, and chromium in the fresh leaves of tea and topsoils of the tea fields in Fouman County, Guilan, Iran. To do so, tea fresh leaves and respective topsoils were sampled at 5 sampling sites. After initial preparation, digestion of the taken samples was performed using HCl, HNO3, and H2O2 reagents. The concentration of heavy elements in the samples was determined by inductively coupled plasma (ICP). There have also been statistical tests such as one-way analysis of variance, T-test, principal component analysis (PCA) and cluster analysis (CA) performed using the SPSS software. Based on the results, the average concentrations of lead, cadmium, zinc, nickel, cobalt, and chromium in soil samples were obtained 3.94, 1.06, 60.29, 22.79, 9.49, and 2.77, mg/kg, respectively. According to the metal pollution load index (0<1), the soil quality of the study area was identified at an acceptable level. The levels of lead, cadmium, zinc, nickel, cobalt, and chromium in fresh leaves were obtained 0.44, 0.08, 22.58, 9.93, 0.23, and 0.36 mg/kg, respectively. Compared to the international standards (WHO / FAO), the amount of lead in fresh leaves was higher than permissible levels. By contrast, the amounts of cadmium, zinc, nickel, cobalt, and chromium were at acceptable values. As for soil samples, only the concentration of cadmium was higher than admissible levels based on the given standards. As such, the leaching process and biological uptake (happened by the rest of the flora) should have a part to play justifying the former results.

Many factors are involved in the production of healthy crop products and their monitoring requires a process-based and systemic approach at all stages from site selection to consumption. The present paper draws upon national and international experiences reflected in reviews in order to identify the most important factors affecting crop quality; the results will be expectedly exploited toward designing future studies and developing measures to improve crop qulity. Soil is the medium in which agricultural production takes place. Although geological formations with high concentrations of pollutants (especially heavy metals) might pollute soil resources, human activities inlcuding polluting industrial activities, improper application of agricultural inputs such as pesticides, chemical and organic fertilizers (especially phosphate fertilizers and non-standard sewage sludge), undertreated effluents, and atmospheric deposits (especially in urban and peri-urban areas) are some of the factors that expose soil and agricultural production more severely to the adverse of effects of such pollutants. Water pollution cannot be divorced from that of soil as they are closely related. While certain reports attribute soil pollution in parts of Iran solely to heavy metals with geohydrological origins, long-time crop irrigation using wastewater with high pollutant loads should not be ignored as a serious source of soil pollution. It should be noted that management plays a pivotal role in growing healthy products via using healthy inputs while maintaining biodiversity but that this cannot be achieved in the absence of such healthy basic resources as: a) soil, b) water, and c) air. In other words, unhealthy crops with pollutant loads result from both production processes and the environmental factors affecting them. A review of some domestic studies revealed that extensive background experience is required in the various sampling, measurement, and reporting skills, given the high sensitivity of these processes, to arrive at sound interpretations of the results of nitrate and heavy metals concentrations reported in some domestic journals. These studies have reported high concentrations of nitrate in spinach, lettuce, and celery but lower concentrations in such fruits as tomatoes, watermelon, and cantaloupe. Crops such as cucumbers, celery, and potatoes reportedly accounted for the highest nitrate concentration exceeding the allowable nitrate limits but minimum levels in tomatoes, watermelons, and cantaloupes. This is while heavy metal contaminations in plants have not been extensively reported on. Production of crops with allowable limits of pollutants presupposes due consideration of the factors outlined above. The approach proposed in this article requires soil fertility management, proper selection of crop species and cultivars, prohibited farming in contaminated lands, and avoidance of soil exposure to atmospheric deposition and polluted waters. These goals, in turn, may be achieved through accurate monitoring of agricultural product quality and identification of high-risk farming regions.

 Toxicity of heavy metals and their accumulation in soil, plant and food chains is one of the main environmental and health problems of today's societies. In this regard, the impact of these metals on valuable medicinal plants and forages that enter into the food chain through human and animal consumption is of particular importance. Glycyrrhiza glabra L. is one of the most valuable species which is important in the world due to the presence of important medicinal and nutritional compounds in its roots and rhizomes and has been considered by the pharmaceutical and food industries. The purpose of this study is to investigate the effect of heavy metals of lead and cadmium on the absorption of high consumption nutrients and also the accumulation of these elements in the tissues of the lichen plant.

  This research was carried out in a completely randomized design with two treatments of lead and cadmium in 4 replicates and 6 concentrations in pot culture (a total of 48 pots). The treatments consisted of concentrations of 0, 10, 20, 40, 80 and 160 (ppm) for cadmium and zero, 50, 100, 200, 400 and 800 (ppm) for lead. After preparing bedding and spraying a heavy metal salts solution of lead and cadmium with the above concentrations, rhizomes were cultivated in pots and placed in the greenhouse for 7 months under irrigation and care. Finally, samples of soil and plant (in two parts of the air and underground organs) were prepared and transferred to the laboratory for acid digestion and extraction of lead and cadmium. To assess the plant's ability, TF, BCF and BAC indices were also used to evaluate the accumulation capacity of these elements.

  The results of the comparison of the mean of lead and cadmium in the studied concentrations showed that increasing the concentration of these two elements in the soil did not have a significant effect on the amount of potassium, sodium, magnesium, calcium and organic matter in the aerial and underground parts of this plant. While the increase in the concentration of cadmium in the soil has a significant reducing effect on the amount of this metal in the air and underground organs and the amount of nitrogen in the air. Also, the increase in lead concentration has a significant effect on the amount of this metal in the air and underground organs and the amount of phosphorus and nitrogen in the air.

 The results of the study on the accumulation and transfer of cadmium and lead in the lichen plant showed that the plant could play the role of stabilizing plant and extractive plant in these two heavy metals, respectively

Sediments can be sensitive indicators for monitoring contaminants in aquatic environments. Therefore, understanding the mechanisms of accumulation and geochemical distribution of heavy metals in aquatic systems and providing basic information for judging environmental health risks, spatial study of metal concentrations in sediments and their comparison with non-contaminated bases is of great importance. One of the common methods of soil pollution assessment is the use of pollution factor index (CF). The calculation of this index requires determining the background of the elements under study. For this purpose, statistical methods based on mean and standard deviation of data are commonly used. Due to the skuwness of the distribution of geochemical data, the use of this parametric method is limited, so the use of methods resistant to outlier data can be proposed as an alternative approach. In the last two decades, the fractal method has been used to separate communities in data related to many disciplines of earth sciences. In order to evaluate the two mentioned methods, 770 samples of waterway sediments containing six metal elements of As, Cr, Cu, Ni, Pb and Zn were collected in an area that is located in the north of Khorramabad. The background of the elements was determined by both methods (statistical method resistant to outlier data and fractal method) and finally the CF index was calculated. This index based on statistical methods assessed at the intermediate level for arsenic, chromium, copper, nickel, lead and zinc 7.5, 0.8, 5.5, 0.5, 4.7 and 9.2 percent, respectively. For the mentioned elements based on fractal method, the medium level of contamination were 39%, 28.9%, 88.6%, 39.4%, 45.7%, 73.4% of the total sample, respectively. In addition, with the second method, 3% (copper), 0.1% (lead) and 4.3% (zinc) of the number of samples have been evaluated at a considerable level. The results showed that the use of statistical methods in determining the background of the elements, despite the selection of a statistical method appropriate to the distribution of data, has reduced the sensitivity of the pollution index and reduced the efficiency of the index in the separation of pollution classes. While the use of fractal method due to considering the spatial dimension (area) in separating different background communities from anomalies leads to better efficiency of CF index and thus improves regional pollution estimates.