khadijeh khermandar

Industrial development and human activities intensify the propagation of various contaminants in the environment. Heavy metals from various sources, such as industrial and agricultural activities, cause serious environmental hazards for the ecosystem. Environmental dusts are sometimes manmade, due to the activity of industries and human units, known as industrial dusts. The purpose of this study was to investigate the effect of industrial dust emitted from the Bauxite crasher located in the upstream of Jajarm Alumina Factory on the level of soil pollution. The study is focused on two heavy metals: Arsenic (As) and Nickel (Ni).

In this research, with regard to the wind roses of the area, first the direction of the dominant and erosive winds was determined. Then, two transects were considered: a transect in the direction of erosive wind (transect A) with 3 km length, and a transect in the direction of the dominant wind (transect B) with 5 km length. Samples from the soil surface (at a depth of 0-2 cm) were taken on these transects at regular intervals from the source of dust, i.e. Bauxite crusher. In total, 46 soil samples were collected. The concentration of Arsenic and Nickel in the soil samples was determined by the method of Inductively Coupled Plasma - Optical Emission Spectrometry (ICP-OES), after acid digestion by chemical means in the laboratory. Finally, the indicators of land accumulation, pollution, comprehensive pollution and enrichment were used to determine the contamination level. Significance of increase in Arsenic and Nickel concentrations, as well as the other contamination coefficients were analyzed in SPSS software using ANOVA and T-test.

The Earth's accumulation index in the direction of erosive wind for Arsenic, at a distance of 200 to 250 m from the source, showed a medium to severe contamination. For nickel, from the source of dust production to 350 m distance, the area was identified unpolluted to medium contaminated. For Arsenic, in the dominant wind direction at a distance of 150 m and 250 to 450 m, moderate to severe pollution was determined. For Nickel, up to 900 m from the source of dusts, the area was identified unpolluted to medium contaminated.For Arsenic and Nickel, The pollution index in the direction of erosive wind up to 450 meters from the source of dust production shows a high to medium pollution level. And show medium and low to end transect, for Arsenic and Nickel. By this indicator, the high pollution levels in the dominant wind direction were determined for Arsenic up to 1200 m from the source of dusts, and medium pollution levels of the index of pollution was determined for Nickel, from the source of dust production up to 500 m far apart. And show medium and low to end transect, for Arsenic and Nickel. Comprehensive index of pollution in the case of erosive and prevailing winds for Arsenic and Nickel showed high and medium pollution levels, respectively. Enrichment factor in the direction of erosive wind indicated medium concentration of Arsenic at 350 and 400 m from Bauxite crusher, and a low enrichment for Nickel at all points. In the dominant wind direction, a medium enrichment factor for Arsenic was observed up to 250 m from bauxite crusher, while the level of Nickel enrichment at all locations was low. Finally, the statistical analysis justified the significance of the measured concentrations of Arsenic and Nickel, as well as the other coefficients of pollution level in the direction of prevailing and erosive winds.

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.

Soil contamination by heavy metals is a significant environmental problem worldwide. Human activities, including mining, are a source of pollution to natural resources. In this study, the phytoremediation potential of rangeland species including, Artemisia sieberi Besser, Zygophyllum atriplicoides Fisch. and C.A. Mey for the absorption of heavy metals of Ni, Co, As, Cr and V was investigated around the bauxite crusher of the Jajarm alumina mine in the direction of the prevailing wind. Soil sampling was performed at the distances of 450-700, 800-1200, 1400-2000 and 2500-5000 meters from the center of the bauxite crusher, and the control site. For this purpose, the seeds were planted in pots with a 3:1:1 ratio of sand, fertilizer and soil. Two-months later, they were transferred to pots with soils sampled from target distances. After completing of a vegetative period, the phytoremediation potential of the species was performed a factorial experiment in a completely randomized block design with three replications in greenhouse conditions. Results indicated that As, Ni, Cr, and Co absorption in above/underground of A. sieberi tissues were higher than Z. atriplicoides. But V absorption in above/underground of Z. atriplicoides tissues were higher than that for A. sieberi and between the vanadium accumulation in the aerial and underground organs of the target species and distances a significant difference was observed at the level of 1%. The amount of heavy metals transfer factor for A. sieberi and Z. atriplicoides was more and less than one in turn. Therefore, in terms of the transfer factor, A. sieberi has a potential for phyto-extraction and Z. atriplicoides has a potential for phyto-stabilization. The results also showed that A. sieberi and Z. atriplicoides were recognized as hyper-accumulating of nickel and cobalt metals. These species can therefore be recommended for the ecological restoration of soils polluted by heavy metals, especially nickel and cobalt in similar regions.

One of the most critical environmental problems globally is soil erosion, which leads to several problems in the field of economy and sustainable development. This study aims to use new methods in soil science studies of the paired sub-catchments to update service descriptions in Dehgin, Hormozgan Province. For this purpose, to select sampling sites of pedons and soil samples, the conditional Latin Hypercube sampling (cLHS) method was used using environmental covariates (digital elevation model), which derivate from unmanned aerial vehicles (UAV), phantom4 pro, and multirotor. The results showed two main land types in the study area, including hills, plateaus, and high terraces. Soil development in the region is mainly influenced by elevation, and the soils of the hill lands are directly related to the type of parent material and slope percentage. In the areas containing wooded pasture and areas with silt loam texture class, the aggregate stability values are higher, which are auxiliary covariates essential and influential parameters in the aggregate stability map. The RMSE and R2 values are 0.32 and 0.26, respectively, for the evaluation map criteria. The values of cation exchange capacity (CEC) and nitrogen in both control and sample sub-catchments are small and the maximum amounts of soil organic carbon in the sample sub-catchment are higher than in the control sub-catchment. The use of new methods including UAV, accurate sampling methods using high-resolution environmental covariates, and digital soil mapping can reduce the number of soil samples, increase the accuracy of output maps, and provide more accurate erosion estimation results, which has reduced time and cost compared to the old methods.

In this study was purposed to investigate the absorption of zinc by Acacia victoriae. ‎The one year old shrubs were randomly selected in 3 replications and exposed by Zinc-sulfate in four concentration (0, 50, 250, 500 mg/l). Some of the morphological and physiological properties such as plant height, collar diameter, leaf number and area, green and dry weight of plant, tolerance index, grade of growth inhibition and chlorophyll content as well as bioaccumulations of Zn in different plant tissues ‎were evaluated. Results showed that the properties were significantly affected by Zn. However, the effect of high concentration of Zn ‎had slight decrease in the properties, that didn't have any series effects on tree as well as the signs of toxicity with zincwas not observed. In addition, the amounts of accumulation of Zn in the roots were higher than above-ground tissues, so that about 80% of Zn (4794.5 mg/kg), more than 13% of Zn (797.9 mg/kg), and about ‎7% of Zn (488.35 mg/kg) were accumulated in the root tissues, the stem tissues, and the leaves, respectively. The bioaccumulation and transfer factors were also measured to higher one and lower one, respectively. Generally, the result demonstrated that the Acacia victoriae ‎could be affected‏‎ as a phytoremediation‎ in‏ ‏reduction of soil pollution to Zn‏.

As a result of human activities, metal pollution has become one of the most important challenges in soil and water conservation area today. Phytoremediation utilizes plants to uptake contaminants and can potentially be used to remediate metal contaminated soils and waters. This study was carried out with the aim of assessing the ability of Acacia victoriae three months old seedlings in the accumulation of cadmium in their parts (stem and root), transfer it from the roots to the stems and to understand the effect of Cd accumulation on some morphology attributes of the plant. For this purpose, 12 seedlings of A.victoriae three months old seedlings were exposed to Cd in 4 different concentrations: 0, 10, 50 and 100 (mg/l) for period 45 days in completely randomized design with 3 replicates per treatment were considered. The results showed significantly reduction of height, biomass and resistance were observed, compared to the control plants and also symptoms of toxicity in the leafs which become thin, yellow and with brwon spots in high concentrations of Cd were notably. Also Cd accumulation in roots and aerial parts increasing trend with increasing Cd supply up to 100 (mg/l) and root tissue concentration regards to Cd concentration was higher than stem tissues concentration at all treatments. Cdwere accumulated in the roots, stems and leafs of seedlings, more than 72% (19433.33 mg/kg), under 17% (4630 mg/kg) and under 11% (2853.33 mg/kg) exposed to 100 (mg/l), respectively. Bioconcentration Coefficient root and stem, Translocation Factors, Enrich Coefficient and Uptake Index were determined 184.9, 71.20, 0.39, 0.014, 7697.73 mg/kg in high concentrations of Cd, respectively. Indeed, the results confirmed that A.victoriae had the ability to accumulate Cd in the roots so that prevented Cd toxicity symptom. Generally, this desert plant can be used in the process of remediation of Cd soil polluted by way of phytostabilization.

Aim & back ground: Nowadays, one of the major issues in the world is cleaning up soils contaminated with inorganic pollutants. Phytoremediation is one of the methods that due to economic reasons and environmental friendly action which attracted much attention in recent decades. The aim of this study: To assess the potential Zn accumulation in different parts of ornamental palm. In this study one year old ornamental palm seedlings in a randomized design with three repetition, were exposed to ZnSO4 in 4 different concentrations: 0, 50, 250 and 500 (mg Zn2+ L-1) for 45 days. Subsequently Zn2+ uptake was quantified in roots, shoots and leaves of the seedlings by Atomic Absorption Spectroscopy (AAS). In addition, some morphological and physiological parameters such as biomass production, shoots and roots length, plant appearance and some other elements were measured. The results of analysis of variance (ANOVA) showed that the traits such as fresh and dry weight tolerance value, collar diameter, plant height, tolerance stress, index of plant resistance, relative water content and deficiency saturated absorption cell, had been significantly effected by Zinc treatments. The results also showed that ornamental Palm seedlings have the ability to accumulate zinc manifold in roots than shoots and leaves. In addition, the species has the coefficients of bioaccumulate more and transport factors less than one unit. Based on these results, we can recommend the ornamental Palm as stabilizer species for the cleanup of contaminated soils with zinc heavy metal.