جستجوی مقالات مرتبط با کلیدواژه « phytoremediation » در نشریات گروه « زراعت »

In order to investigate the feasibility of phytoremediation of cadmium nitrate-contaminated growth substrates with weeds, a factorial experiment was conducted in the form of a completely randomized design in the spring of 2021-22.

The experimental factors included weeds (Portulaca oleracea, Chenopodium album, and Amaranthus retroflexus) and the gowth substrate contamination with cadmium nitrate comprising levels of zero (control), 25, 50, and 75 miligrams per kilogram of soil.

The results showed that with increasing consumption of cadmium nitrate, the amount of cadmium in the shoots, roots and biological factors exhibited an increasing trend. The amount of root cadmium was higher in P.oleracea, but the concnetration of shoot cadmium in Ch.album and A.retroflexus showed a significant increase compared to that of P.oleracea. Therefore, in purslane, the transfer of cadmium from the roots to the shoots was probably less than that of Ch.album and A.retroflexus. With the increase in cadmium nitrate concentration, ion leakage displayed an increasing trend, and  leaf relative water content and chlorophyll content displayed declining trends. On the other hand, the catalase and ascorbate peroxidase enzymes in leaves showed an increasing trend with increasing cadmium nitrate consumption. Also, the highest activity of antioxidant enzymes was observed in A.retroflexus weeds.

Generally, with the mentioned characteristics, ther P.oleracea plant can be considered as a hyperaccumulator, and Ch.album and A.retroflexus can be considered as moderate accumulators of cadmium metal.

In order to evaluate the ability of forage sorghum (Sorghum bicolor L.) to remediate the heavy metal cadmium with biochar and Pseudomonas putida, a factorial experiment has been conducted based on completely randomized design accomplished in greenhouse conditions with four replications at Sari Agricultural Sciences and Natural Resources University, in the summer of 2019. Results show that the presence of cadmium in the medium of sorghum reduce the dry weight of root and shoot. However, adding biochar and bacterial inoculation significantly increase the mentioned traits. Bioconcentration factor and bioaccumulation factor have increased from 25 to 100 mg of cadmium, when the highest shoot bioaccumulation factor (2.31) is observed at a concentration of 100 mg Cd per kg soil and in the simultaneous application of Biochar and Pseudomonas putida, which is a significant increase of 28.33% compared to the control. The lowest translocation factor of sorghum (1.000) is related to non-application of biochar, non-inoculation of Pseudomonas putida and without cadmium contamination, itslef reduced by 20% compared to the control, while the highest translocation factor (1.94) is observed at a concentration of 25 mg of cadmium per kg of soil and treatment of non-application of biochar and non-inoculation of Pseudomonas putida. Plant tolerance index has decreased by increasing cadmium concentration, while the use of biochar and inoculation of Pseudomonas putida has increased this index when the highest tolerance index (1.22) is related to the treatment of combined use of biochar and bacteria with no cadmium, increased by 22% compared to non-application of biochar and non-inoculation bacteria. As the tolerance index of forage sorghum in all concentrations of cadmium is more than 0.60, this plant can be classified in the highly-tolerant group to the heavy metal cadmium stress and sorghum could be used for cadmium phytoremediation.

 Heavy metals refer to a group of metals or semi-metals whose atomic density is greater than 4 or 5 grams per cubic centimeter. What has caused concern about environmental pollution today is the accumulation of the chemical waste in the soil. Although copper is a micro-element for plants, it is toxic at high concentrations. This element causes structural, morphological, physiological, and biochemical changes in plants. Today, the phytoremediation technique is used as a suitable method for cleaning and removing water, soil, and air pollution. More than 400 species of overgrown plants have been identified. Studies have shown that Aegilops tauschii is a drought-resistant plant. Since, the stress of heavy metals can cause secondary drought stress.

This research was performed to investigate the effect of the heavy metal copper on some physiological, morphological, and biochemical parameters of Aegilops tauschii. Therefore, the effect of different concentrations of copper (zero, 5, 25, and 125 micromolar) was studied on the physiological, biochemical, and morphological characteristics of 37 genotypes of Aegilops tauschii in the greenhouse condition.

 The results showed that increasing copper concentrations decreased the amount of chlorophyll b, carotenoid, cell membrane stability, seed diameter, relative leaf water content, leaf retained water and single plant yield; while total chlorophyll, chlorophyll a, carbohydrate, proline, relative leaf water loss, root length, and root weight increased significantly. In terms of biochemical parameters, Genotypes 11, 58, and 85 with the highest values of morphological, physiological, and biochemical indices were resistant to copper. Among the mentioned genotypes, Genotype 58 with the highest yield as a resistant genotype, and Genotype 23, 28, 30, 52, 99 and 123 were subjected to copper stress more than other genotypes based on the morphological, physiological and biochemical indicators, among which Genotype 99 with the lowest yield could be introduced as the most sensitive genotype.

According to the results, it seems that some genotypes of Aegilops tauschii were resistant to the heavy metal copper. Resistant genotypes could be recommended for phytoremediation in copper-contaminated areas.

One of the important environment pollutants can cited to element lead (Pb) that effected on absorption of nutrients in plants. This investigation was conducted in order study effect zeolite and Mycorrhiza on quality and quantity soyben plant on soil polluted with Pb in greenhouse Faculty of Agriculture, University of Lorestan. The experiment was carried basic factorial in from to random completly design with three repeat. Treatments were incloud; Mycorrhiza fungus in two level (control and application Mycorrhiza) and zeolite in three level (0, 5% and 10% W/W). Soil’s all plots were polluted with concentration 200 mg/kg Pb (NO3)2. Result this investigation indicued, exept height plant, number grain per pod, number pod per plant and number of branches that influenced by main effect Mycorrhiza and zeolite, in other traits intraction was significant. Application zeolite 10% with Mycorrhiza resulted improve LAI (84%), catalase (150%), superoxide dismutase (220%), 1000 grain-weight (51%), grain yield (94%), biological yield (51%) and harvest index (34%) and decreased accumulation of lead in root (43%) and shoot (44%), TF(75%) and BCF in root (43%) and shoot (43%). Heighest grain yield (3609 kg.ha-1) and biological yield (9026 kg.ha-1) was obtained from use Simultaneous zeolite 10% and Mycorrhiza. Overall application Mycorrhiza and zeolite in addition to decline effects heavy metals in the soil and improve quantitative and qualitative yield of the product can be effective in phytoremediation of heavy metals.

In regions with severe limitation of fresh water, salinity poses a serious threat to agriculture production due to its toxicity to most plants. Salinity tolerant plants that can survive and grow in high-salinity conditions are called halophytes. Halophyte cultivation has the potential to restore saline environments, provide for global food demands, produce medicine and biofuels, and conserve fresh water. Two approaches are presented to developing tolerant plants of seawater salinity; the first is increasing tolerance of conventional plants, and the second is choice from the large pool of halophytes, which already have the requisite salt tolerance. The difference between the upper limit of salt tolerance of conventional plants and required tolerance level to seawater salinity is huge. It has been shown that Salicornia spp. has the potential to tolerate salinity of seawater. Salicornia is a genus of succulent, halophyte flowering plants in the family Amaranthaceae that grow in salt marshes, on beaches, and among mangroves. Pickleweed (Salicornia bigelovii Torr.) is an obligate halophyte that has been considered as a promising plant due to the tolerance to hypersaline water and economic values such as forage production, oilseed production and fresh consumption. This study evaluated the response of Salicornia bigelovii to different water salinity treatments, determines its salt tolerance threshold and shows trend of the accumulation of Ca2+, Cl-, Na+ and K+ ions in the plant shoots.

This experiment was conducted as a completely randomized design with 4 replicates in the greenhouse of the National Salinity Research Center, Yazd, Iran. Saline water treatments included 2, 5, 8, 11, 14 and 17 dS m-1, which were prepared using dilution of Persian Gulf water. Salinity treatments were applied as irrigation of pickleweed (Salicornia bigelovii) plants with related saline water treatments. The 10 uniform seeds were sown in pots and were kept in a controlled environment with 26/18 °C (±3) day/night temperature regimes. The 84 days plants were harvested and were immediately transferred to the laboratory. Fresh and dry weight, dry matter, ash content and concentration of calcium (Ca2+), chloride (Cl-), sodium (Na+) and potassium (K+) were measured in shoots. Data were subjected to analysis of variance, and the means were compared using LSD at 5% probability level. Response cure was used to determine the threshold level of reduction after reaching the peak.

The results showed that salinity treatment was significant on all traits, except dry matter percent and potassium concentration. The results showed that increasing salinity up to 8 dS m-1 increased fresh and dry weight, however higher salinity levels were associated with reduction. The threshold level of reduction after reaching to the peak were 8.65 and 7.01 dS m-1 for fresh and dry weight, respectively. The amounts of reduction in fresh weight in 2, 5, 11, 14 and 17 dS m-1 treatments compared to 8 dS m-1 treatment were 26.9%, 9.5%, 12.0%, 20.0% and 35.8%, respectively. These reductions were 23.4%, 20.7%, 27.4%, 38.9% and 41.7%, respectively in dry weight. With increasing salinity of water, the ash content of shoots had an ascending and significant trend. The lowest and the highest shoot ash were related to 2 and 17 dS m-1 water salinity, by 24.8% and 41.3%, respectively. As salinity was increased, the concentration of chlorine and sodium in shoots were enhanced, while the concentration of calcium and potassium were reduced. Correlation and stepwise regression analyses revealed that concentration of calcium and potassium were the most important traits in salinity tolerance of salicornia. It seems that salinity tolerance in salicornia occurs by osmotic regulation as the accumulation of salts in its tissue.

According to the results of this study, it can be concluded that the capability of ions accumulation strengthens the phytoremediation ability of salicornia, however increasing in ash content could have a negative effect on the forage value of the plant. Therefore, determining the nutritional value of salicornia and feed analyzing in the presence of livestock require further evaluation.

 Aeluropus is one of the native halophytes of Iran that can absorb, transfer and excrete salt through the saline glands. Bisphenol A (BPA) is found in the effluents of municipal and industrial wastewater treatment plants, surface, and groundwater and due to estrogenic activity, it increases testicular and breast cancer. Grass species are suitable for phytoremediation because of their root system.   

 This study was conducted to investigate the Morphophysiological response of Iranian native Aeluropus littoralis to BPA in symbiosis with mycorrhizal as a factorial experiment in a completely randomized block design with 48 pots. Treatments included 4 concentrations of BPA (0, 5, 10, and 15 ppm), 2 levels of mycorrhizal inoculation (non-mycorrhizal plants, and plants inoculated with glomus mosseae) and 3 repeats (2 plants per repeat). The seeds were placed in a transplant culture tray containing a mixture of sand, vermiculite, and soil (1: 1: 1) and irrigated 1 month. In the next step, the seedlings were transferred to another pot (bucket 4) to perform mycorrhizal fungal treatments, so that 5 g of mycorrhiza was added to the soil of each pot, and then the BPA pollutant was treated with irrigation water for two months.  

 The results showed that the effect of BPA was different depending on the concentration. Leaf area, number of stems, number of leaves and height increased at a concentration of 5 ppm and this concentration did not show a significant difference with 10 ppm treatment, but with increasing concentration to 15 ppm, a decreasing effect on these traits was observed. As the BPA concentration increased to10 ppm, the root dry weight, root area, and root volume increased. Root length, chlorophyll concentration, ion leakage up to 5 ppm did not differ significantly, and at higher concentrations the root length and chlorophyll concentration decreased and ion leakage increased. Root wet weight and RWC increased with increasing contamination to a concentration of 10 ppm, but decreased at concentrations of 10 and 15 ppm. As the concentration of BPA increased, the percentage of BPA soil uptake by the plant decreased and the cumulative amount of BPA (leaf and root) increased. With a threefold increase in the concentration of the contaminant, leaf bisphenol A doubled. The effects of mycorrhiza on all non-height traits were significant. Plants inoculated with mycorrhiza had lower ionic leakage than non-inoculated plants, and the rest of the traits evaluated in inoculated plants increased.  

 In plants inoculated with mycorrhiza, the BPA in the leaves and the absorption of BPA from the soil were 30% and 40% higher, respectively, than the non-inoculated plants. The inoculated plants were able to absorb more BPA. Aeluropus can absorb up to 80 percent of the soil's BPA and excrete it through its salt glands through its transfer to the shoots, indicating this plant's high compatibility and resistance to BPA contaminants.

In contaminated soils, poor plant establishment and plant biomass reduction decrease the efficiency of phytoremediation. In this study, pretreatment effect of potassium humate (300 mg/L) and compost tea (5:1) on sunflower tolerance under different concentrations of cadmium (0, 50 and 100 mg/kg soil) was evaluated. A factorial experiment based on a completely randomized design was conducted with four replications, in 2016. Results showed that increasing cadmium concentration significantly reduced root, stem and leaf dry weight, as well as the amounts of chlorophyll a and b, and increased carotenoids, proline and electrolyte leakage. Seed priming with potassium humate and compost tea improved the negative effect of contaminated soil with cadmium on the above parameters, but their effects on the measured traits were different. Root , stem  and leaf dry weight, chlorophyll b, proline content and root  and shoot cadmium concentration were increased due to the application of potassium humate under cadmium contamination. However, compost tea significantly increased chlorophyll a and carotenoid as well. Both priming treatments significantly increased cadmium transfer factor for sunflower plant. In general, it can be concluded that, with potassium humate and compost tea the tolerance of sunflower plant improves in contaminated soils through photosynthesis pigments and proline content increment and electrolyte leakage decline.

During past centuries and industrial activities of human that have been include of agriculture, military and disposal of industrial wastes caused that wide region specially, developed countries face with high concentrations of heavy metals and pollutants. Moreover, negative effects on ecosystems and other natural regions, these regions created too many risks for human health because of food pollution by usage of agricultural productions and drinking water. The aim of this research, discussion about phytoremediation with use of local techniques and those potentials is as a corrective technique that from natural capability of biotic plants use for removal and purification of pollutant components of environment. This research was done as completely randomized blocks design with 3 replications during 2011for evaluation of efficiency amount and amplitude of usage of herbal exploitation method by offensive plant Chrozophora tinctoria for purification of around solis of Iralko complex. At first Zn, Ni and Cr elements measured in soil, then in the control treatments, 2.5, 5 and 10 fold of sample mean concentration, the amount of uptake and storage in different plant organs were investigated. The results showed that the highest amount of Zn (61.63%) and Chromium (67.33%) were found in leaf and stem, respectively. According to the results, it can be stated that Chrozophora tinctoria have an effective role in the removal of Zn and Cr in the complex surrounding soils.

Industrial pollutants entering into the soil leads to the accumulation of excessive heavy metals such as lead, cadmium, copper and zinc in the soil. Phytoremediation is a method to remove heavy metals from the soil. Phytoremediation is one of the most important methods and technologies has been developed during the last two decades to solve the problem of metal pollution in different countries, Where the cultivated plants to clean, absorb and remove contaminants from the soil is presented. The chemical reaction of metals in soil is one of the key issues in the discussion of phytoremediation of heavy metals so in phytoremediation using chemical and organic substances increase the solubility of contaminants and in this way to improve the efficiency of the refining of pollutants by plants. Add chelating agents can increase the efficiency of metal uptake by plants. Soil application of chelating agents Such as Ethylene diamine tetra-acetic acid, increased the concentration of metals Such as lead in plants through increased solubility of metal and increased transfer it from the roots to stems. Ammonium molybdate has the ability and potential to precipitate Pb and Zn and reduces the toxicity of these metals in the plant. Ammonium molybdate has ability to producing chelate to form more soluble sections with Cd, Cu and Ni, this feature increases the bioavailability of these metals to the plant. The objectives of this study are evaluation of the effects of ammonium molybdate to increase the bioavailability of lead in corn plant and compare it with Ethylene diamine tetra-acetic acid for the removal of contaminants from the soil. For this experiment was conducted in a completely randomized design with factorial arrangement with three replications in greenhouse of Agriculture and Natural Resources Research Center of Kerman province, Iran. Experimental factors included four levels of lead (zero (Pb0), 150 (Pb1), 300 (Pb2) and 450 (Pb3) milligrams of lead per kilogram of soil from the source of lead chloride) and two types of chelating agents, Ammonium Molybdate (concentration of Mo 10 mg per kg of soil) (AM) and Ethylene diamine tetra-acetic acid (one gram per kilogram of soil) (E) and control. Some of the physical and chemical properties of the soil were measured. In order to contaminated samples of soil, the required value of lead, Ethylene diamine tetra-acetic acid and ammonium molybdate were added to the soils by spray method. After preparing the soil samples, the seed of corn plant (Zea mays L.) was cultivated in soils contaminated by experimental treatments. After harvesting, plant samples transfer to the laboratory, was dried, weighed and milled. Plant samples were digested by dry digestion and were measured the amount of lead in the shoots and roots. Soil samples were transferred to the laboratory for next analysis. Parameters was measured such as dry weight of shoot and root, the concentration of lead in shoot and root, absorption of Pb in shoot and root and availability of Pb in soil by DTPA method. Analysis was performed by using SAS statistical software and figures were drawn in Microsoft Excel. The highest available lead content in soil (extracted by DTPA) is related to Ethylene diamine tetra-acetic acid treatment which it was higher than 29.5% compare to control. The results showed that different levels of lead and form chelates have significant effect (p<0.01) on dry weight of root and shoot, relative concentration of lead in root and shoot and total absorption of lead in root and shoot. Ammonium molybdate was significantly increased dry weight of root and shoot. According to the results of the highest dry weight of root and shoot of corn plant is related to the level of unleaded (Pb0), the chelate of ammonium molybdate. The highest relative concentration and total absorption of lead in root and shoot was obtained Ethylene diamine tetra-acetic acid-treated at 450 mg per kg of lead (Pb3). Ammonium molybdate compared with Ethylene diamine tetra-acetic acid had a less ability to absorption of lead. Obtained results of the comparison amounts of lead of roots and shoots of plants under the effect of use of ammonium molybdate and Ethylene diamine tetra-acetic acid, showed that Ethylene diamine tetra-acetic acid was more effective in increasing concentrations of the element in the corn plant.

In the contaminated soils, the poor plant establishment and reduction in  plant biomass will reduce the efficiency of phytoremediation. In this study the effect of sunflower seed pretreatment with salicylic acid (100 mg/L) and potassium nitrate (2%) on its enhancing tolerance under different concentrations of cadmium (0, 50 and 100 mg/kg) were evaluated. Results showed that increasing of cadmium concentration significantly reduced the root dry weight, stem dry weight and leaf dry weight, chlorophyll a, chlorophyll b and increased carotenoids, proline content and electrolyte leakage. Seed priming with salicylic acid and potassium nitrate improved the damage effect of contaminated soil with cadmium on mentioned parameters. Under cadmium stress, potassium nitrate increased stem dry weight, leaf dry weight, chlorophyll a, aboveground cadmium concentration, and translocation factor. However, salicylic acid increased root dry weight, chlorophyll b and root cadmium concentration. Under highest concentration of cadmium, electrolyte leakage and proline content were reduced by salicylic acid (by 18%, 22%, respectively). In general it can be concluded that salicylic acid and potassium nitrate with increasing photosynthesis pigments and proline content and reducing electrolyte leakage increased of sunflower tolerance in contaminated soils with cadmium

Among the major environmental pollutants, lead is the most substantial contaminant due to causing toxicity in plants and organisms. Recently, the remediation of these metals has been considered in plants. Plant in vitro culture is a key tool in phytoremediation research. In general, Plant tissue culture and in vitro selection techniques are used to increase the tolerance and the accumulation of heavy metals which have been reported in numerous plant species and populations. The application of ornamental plants for phytoremediation in metal-contaminated soil is a new alternative. Ornamental kale is an important bedding plant in many landscapes of cold temperate regions. The present study was aimed to evaluate the Pb resistance and remediation of Brassica OleraceaVar. Acephala affected by in vitro culture as a bedding plant. This experiment was carried out in 2016 at Arak University.
  In this study, the stalk explants of Brassica OleraceaVar. Acephala was used for callus induction. Callus and plantlet were exposed to different concentrations of lead in the media. The Callus induction medium was MS (Murashige and Skoog) supplemented with 0.1 mgL-1 2,4-D and BA. The regeneration medium was MS medium supplemented with 0.5 mgL-1 NAA in combination with 1 mgL-1 BA. The rooting medium was half-strength MS medium without plant growth regulators and sucrose. All of the media containing 30 gL-1 sucrose, 7 gL-1 agar, and pH were adjusted to 5.8. All of the regeneration stages from callus induction to rooting and the acclimatization stages were done by different concentration of Pb(NO3)2 (0, 10, 25, and 50 mgL-1). The traits, such as callus browning, fresh and dry weight, callus formation, survival rate, root and shoot length, leaf number, and the lead accumulation, were evaluated during various stages of callus regeneration and rooting in plantlets. A Completely Randomized Design (CRD) arrangement with three replications was used in this experiment. Data were analyzed using the ANOVA procedure of SAS statistical software (version 9.2).
  Based on the results, not only did different concentrations of lead not have the toxic effects but also they had a stimulation effect in some concentrations on callus growth and regeneration. Lead concentrations increased leaf number and length of shoots in the regenerated ornamental kale. Lead accumulation in cultures was increased by increasing the concentration of lead in the medium at all stages of the regeneration. The highest accumulation of Pb was obtained 2395.7 ppb in callus treated by 25 mg L-1 Pb in media.
  The results of the present study showed the occurrence probability of the somaclonal variation due to 2,4-D supplemented in the media. In the regenerated plant, results revealed that the growth traits and Pb uptake were affected by Pb concentrations. Some in vitro derived plantlets showed an increase in uptake potential of lead in their organs (6.1 to 2.7 times compared to the control) and that it is remarkable and suitable for phytoremediation studies.

Microcosm experiments were conducted under controlled environmental conditions in order to estimate growth response and phytoremediation ability of A. japonica and A. pinnata. Plants were exposed to solutions of different Cu-concentrations [Cu] (0, 1, 2, 5 and 7 mg L-1) and Zn-concentrations [Zn] (0, 0.5, 1, 2 and 4 mg L-1) under different incubation periods (0, 3, 6, and 12 days) along with control treatments. Lower metal concentrations [< 2 mg L-1 (Cu) and < 1 mg L-1 (Zn)] enhanced plant growth; however, growth was significantly inhibited at higher concentrations during Longer Incubation Periods (LIPs). Azolla species showed substantial metal removal capacity (on an average, Removal efficiency> 80% for Cu and > 60% for Zn during LIPs). The higher the metal concentrations with LIPs, the higher the metal removal amounts. Plant`s exposure to high (Cu) and (Zn) during LIPs showed changes in color and detachment of the roots that might result in plant death due to phytotoxicity effect. Highly significant relationships (r= 0.91** & 0.82** for Cu and r= 0.93** & 0.92** for Zn in case of A. pinnata and A. japonica, respectively) between metal removal amounts and metal concentrations in biomass indicated that phytoaccumulation was the possible mechanism for phytoremediation because the metals removed from solutions were actually accumulated into the plant`s biomass. The high value of bioconcentration factor indicated that Azolla species were hyperaccumulators, and can be deployed effectively for phytofiltartion of Cu and Zn.

Contamination of soils with heavy metals is often resulted from human activities and phytoremediation is an effective and economic strategy to remove toxic metals from soils. Heavy metals are significant environmental pollutants, and their toxicity is a problem of increasing significance for ecological, evolutionary, nutritional and environmental reasons. The term ‘‘heavy metals’’ refers to any metallic element that has a relatively high density greater than 4 g/cm3, or 5 times or more, greater than water and is toxic or poisonous even at low concentration. However, chemical properties of the heavy metals are the most influencing factors compared to their density. Heavy metals include lead (Pb), cadmium (Cd), nickel (Ni), cobalt (Co), iron (Fe), zinc (Zn), chromium (Cr), iron (Fe), arsenic (As), silver (Ag) and the platinum group elements. Plants experience oxidative stress upon exposure to heavy metals that leads to cellular damage. In addition, plants accumulate metal ions that disturb cellular ionic homeostasis. To minimize the detrimental effects of heavy metal exposure and their accumulation, plants have evolved detoxification mechanisms. Such mechanisms are mainly based on chelation and subcellular compartmentalization. Chelation of heavy metals is a ubiquitous detoxification strategy described in wide variety of plants. The aim of this study was to investigate the effect of different compounds to reduce the toxicity and accumulation of heavy metals in the planting bed is pinto beans. In order to evaluate the effects of different growing substrates on reducing toxicity and phytoremediation bean (cv. Sadri) under heavy metals, a greenhouse experiment was conducted as a factorial for four heavy metals (Cd(NO3)2, Pb(NO3)2, Ni(NO3)2 and CuSO4) seperately, based on CRD design with three replications in Yasouj University, 2013. The first factor included of four levels of different growing substrates (control, compost, vermicompost and Populus sawdust) and the second factor included of two levels of heavy metals (heavy metals with 50 mg kg-1 soil concentration and control). Analysis of variance showed that the effect of organic compounds and cadmium nitrate in the soil and their interactions on amounts of cadmium accumulation in roots, shoot and grain was statistically significant. Compost and vermicompost significantly increased cadmium. Vermicompost can be used to remove metals from contaminated soils used because it is linked with metals and increases nutrient uptake by providing. A cadmium concentration in shoot tissue was more than adequate at all levels of the leveas (0.2-0.05 mg/kg dry weight). Lead levels in the tissues of roots, shoots and seeds in all treatments were the detection limit. It seems that due to the low accumulation of lead in beans can be attributed to the low mobility of lead in soil and plant. Means comparison showed the highest accumulation of nickel in the root of the control (normal soil) with an average of 14.45 mg/kg dry weight of roots and the lowest value of this attribute in use of poplar sawdust with an average of 11.42 mg/kg root dry weight that using compost and vermicompost was not significantly different. Analysis of variance showed that the effect of organic compounds in soil, copper sulfate and their interactions on the amount of copper metal roots was significant. When the low copper concentration in soil, compost and vermicompost with the stabilization of copper available and disabling decrease copper absorption and accumulation by the plants, but the high concentration of copper in the soil, add compost, vermicompost and poplar sawdust will not be enough to stabilize all accessible copper. In this study, the use of poplar sawdust to accumulate the highest amount of copper in copper sulphate roots in levels zero and 50 mg per kg dry weight soil. The results showed that the use of compost and vermicompost increased amounts of cadmium accumulation in shoot and root. On the other side, compost and Populus sawdust decreases the amount of nickel in the bean shoot and root. Also, the highest accumulation of copper in roots of beans was achived by application of the Populus sawdust and compost. Accumulation of heavy metals in roots far more than shoots and seeds. In general, the results of this study showed that due to low accumulation of heavy metals in the seed of bean and high absorption by the root and shoot, this plant is suitable for cultivation in contaminated areas and if possible leaving the roots and shoots is also appropriate for the purification.

  The increase in population and the increase of scientific and technical knowledge and the development of industries without observing environmental issues and standards has contributed to the pollution and collapse of the soil biomass balance. Cadmium is a heavy metal, an inessential and toxic element for plants that it enter to the earth by different human activities. Phytoremediation is one of the more efficient proposal methods in pollution effacement. The advantage of Phytoremediation is adding organic, nutrient elements and oxygen to the soil that improve the quality and structure of the soil in purging places. Plants also, create a cover for the soil and their roots stabilize the soil and thus reduce the wind and water erosion. There are reports about potassium fertilizer with plants for absorption of cadmium and Phytoremediation preferment. The cadmium ion can formed by permanent complexes with chloride quickly. Chlorides are very fluid and can be an important factor in cadmium distribution of the soil in the specific conditions. The aim of this research is investigation the effect of using chloride and potassium sulfate fertilizer to absorption of cadmium and Phytoremediation preferment by canola plant. This research performed into factorial and completely random design with 4 potassium levels (0, 100, 200 and 300 mg/gr K2O) from sources of potassium chloride and potassium sulfate, separately and 3 levels of cadmium (0, 15 and 30 mg/kg) from the source of cadmium nitrate in 3 replications at canola plant in glasshouse of center research. As far the results of analysis of variance of effects of Cadmium and Potassium fertilizers and their interaction have significant effect on the amount of Cadmium of root and shoot, root dry weight and Potassium of root. Also, according to the results, the main effects of cadmium and potassium fertilizers have significant effect on dry weight and Potassium of shoot, whereas the effect of their interaction on dry weight and Potassium of shoot isn’t significant. In the treatment of 15 mg/kg, at 200 and 300 mg/gr levels of Chloride Potassium and 300 mg/gr level of Potassium sulfate into control, increase the content of Cadmium of the root but the content of Cadmium in shoot in 200 and 300 mg/gr levels of Chloride and Potassium sulfate into control increase significantly. The results of interactions in levels of Cadmium and Potassium fertilizers on dry weight of root show that highest amount of the dry weight of root exists in 0 Cadmium treatment (control) in 200 mg/gr level of Potassium sulfate and the lowest amount of dry weight of root has been observed in 30 mg/Kg Cadmium treatment on 300 mg/gr Potassium sulfate level. Highest and lowest amount of dry weight of shoot is related to the control treatment of Cadmium and 30 mg/Kg Cadmium treatment respectively. Also the result of Cadmium treatment shows that the Potassium of shoot decrease significantly with increasing of Cadmium and all levels shows the significant reduction. Highest and lowest amount of Potassium of shoot is related to the 0 level of Cadmium and 30 mg/Kg level of Cadmium respectively. Investigation of the levels of Potassium fertilizers show that adding Potassium fertilizer increase the absorption of the Potassium of shoot has been observed in 300 mg/gr level of Potassium sulfate. In this research, there is significant difference between Potassium fertilizers (sulfate and chloride Potassium), whereas highest amount of the absorption of Cadmium has been observed in 300 mg/gr level in chloride Potassium, so according to the results of the glasshouse experiment, the efficiency of Phytoremediation improved however continuity of researches seem to be imperative in the farm conditions

Considering the increasing environmental pollution, especially heavy metals, it is necessary to find new and inexpensive methods to clean up contaminated soils and waters. The lead is one of the most important environmental pollutants which disturbed nutrient uptake by plant. In order to investigate the potential of some biological agents in phytoremediation of lead and the absorption of nutrients by annual alfalfa in lead-contaminated soil, a factorial experiment was conducted based on completely randomized design with four replications. In the present experimental, the first factor was the heavy metal levels of lead containing lead concentrations (17.5, 417.5 and 817.5 milligram/kilogram) and the second factor was the treatment combinations including the application and non-application of superabsorbent nano polymer, humic acid and bacteria. The results showed that increased lead concentration in the soil reduced the biomass and the relative water content of the leaves and toxic in the plant. But simultaneous use of bacteria and superabsorbent which caused the absorption of water and the application of humic acid, increased the plants efficiency in food intake. The highest amount of transfer factor was observed in treatment of application of 817.5 milligram/kilogram lead and its lowest amount in the treatment of non-application of lead. Also, the use of humic acid and bacteria increased the transfer factor. The results of the present research showed that lead refining is possible by alfalfa plant, and humic acid as a chalking compound with superabsorbent and bacteria can well reduce the effects of lead toxicity in alfalfa.

Although Zn is an essential element for plants, but it is poisonous in high concentrations and affect growth disturbance. This study was performed in 2013 to investigated the effects of different concentration (0, 100, 200 and 400 mg/L) of the Zn and also done a fixed amount (750mg) of SNP on growth and some physiological parameters in Pinus eldarica. Results showed the accumulation of Zn (without SNP) in root, stem and leaves increased when concentration of Zn in soil increased. The most were measured in root (538.80mg/kg) and lowest in leaves (105.73mg/kg). Different concentration of Zn did not significantly effect on Chlorophyll a, b, and total Chlorophyll, MDA, and proline but increased soluble sugar in root and leaves. Also, SNP increased concentration of Zn in soil significantly increased in the root, stem, leaf and root and were measured most in root (662.36 mg/kg) and lowest in leaves (46.16 mg/kg). Generally, due to good resistance in 400 ml/l concentration and also the better accumulations in roots rather than shoots in Pinus eldarica, we can use as refinement in pollutant soils.

IntroductionHeavy metals, as one of the most important factors contaminating natural environments and agricultural ecosystems, are found in almost all industrial regions. Toxic effect of high concentration of heavy metals is also observed in plants. One of the specific characteristic of heavy metals which has high influence in occurrence of toxicity of heavy metals is their bioaccumulation. Heavy metals are not biologically inseparable and decomposable and remain in environment which finally threaten human health. Therefore, removing, or at least, reducing their concentration in agronomical systems is closely related to human health. Cadmium is a heavy metal which is an unnecessary element for plants and enter agronomical systems through pesticides usage. However, cadmium is easily absorbed by plant roots and its toxicity is 20 times more than that of other heavy metals. There are chemical, physical and biological methods for removal of heavy metals from agronomical soils. Phytoremediation is a low cost and environmental compatible method for heavy metal removal from soils. This research was aimed to compare the ability of wheat, clover and rapeseed for removal of cadmium from agronomical soils to achieve the goal of reduction of heavy metal for incoming crop in rotation.
Materials and methodsThe current research was conductedas3×3 factorial experiment based on randomized complete block design with three replications. The first factor was plant type including wheat, clover and rapeseed and the second factor was heavy metal concentrations including 0.0, 50 and 100 mg kg-1 soil. Soil samples were contaminated with cadmium concentrations of 0.0, 50.0 and 100 mg per kg soil. Experimental plots (with height and diameter of 40 cm) were filled with 10 kg contaminated soils. Four weeks after planting, all plants parts (including root and shoot) were harvested and oven dried at 75°C for 72 hours. Finally, cadmium concentration was determined in all plants.
Results and discussion The highest cadmium uptake was observed in wheat under the concentration of 50 and 100 mg kg-1 soil. Increasing cadmium concentration from 50 to 100 mg kg-1 soil had not significant effect on the ability of wheat, clover and rapeseed for cadmium uptake from soil. Plants with high biomass are capable for more heavy metals uptake which is line with the findings of this research where wheat with higher biomass removed more cadmium from soil in comparison with clover and rapeseed. However, nonsignificant difference between clover and rapeseed for cadmium uptake was not compatible with this opinion where rapeseed produced higher biomass. Although different physical, chemical and biological methods are used for removal of heavy metals from soils, phytoremediation has the highest effect for removal of cadmium from soils.
ConclusionThe current research confirmed the results of other experiments about the ability of phytoremediation for removal of cadmium from soil. Furthermore, the results revealed that wheat, in addition to its nutritional value, has a high ability for reduction of cadmium from contaminated soils and can be considered as a good crop in crop rotation programs.