جستجوی مقالات مرتبط با کلیدواژه « گیاه پالایی » در نشریات گروه « زیست شناسی »

Phytoremediation is a cost-effective and environmentally friendly method to remove heavy metals from contaminated soil and the environment and choosing the right plant for phytoremediation is important considering the increasing expansion of urban wastewater. In this regard, an experiment was conducted in the form of a completely randomized design with three replications for 14 months at Guilan University. In this study, the accumulation index of metals (MAI) including zinc, chromium, lead, copper, manganese, nickel, and magnesium was measured in three plants of Cyperus alternifolius L., Chrysopogon zizanioides (L.) Roberty and Aloe vera (L.) Burm.f. treated with urban wastewater, and some of their morphological and physiological characteristics were compared. The results showed that under urban wastewater treatment, the MAI in C. zizanioides and A. vera was higher than in C. alternifolius. In all three studied plants, the indices of root length, shoot length, total biomass, uptake index (UI), and tolerance index (TI) were significantly reduced compared to the control plant, and A. vera had the highest percentage of reduction. Also, the highest percentage of increase in total soluble sugar, total phenol, total flavonoid, total anthocyanin, total tannin, and DPPH radical-scavenging percentage was observed in C. zizanioides. Therefore, it can be said that C. zizanioide was more successful in terms of metal accumulation and morphological and physiological characteristic

Heavy metals, including nickel, are among the most important pollutants. Ni as a micronutrient is essential for plants, however, with increasing concentrations of nickel in the environment, excess of the element accumulated in plants and causing toxicity. Phytoremediation is a biotechnology, using the plant to remove or reduce environmental pollutants. In this study, to evaluate the nickel phytoremediation potential and accumulation, the effects of different levels of nickel on some growth and development characteristics of Mentha longifolia L., were studied. Various concentrations of nickel (0, 10, 50, 100 and 300 mg/l) were treated in hydroponic culture, and in this condition, the plant potential for nickel tolerance and nickel effects on some physiological and morphological characteristics of M. longifolia were evaluated. Experiments were conducted in a completely randomized design. Results analysis showed that characteristics: shoot and root length, leaf area, shoot and root dry weight, total chlorophyll, carotenoid, anthocyanins and soluble carbohydrates content of the plant were reduced by increasing the concentration of nickel in nutrient solution but total protein and shoot and root nickel content were increased. Overally, based on evaluating of the effects of nickel on vegetative and physiological characters of M. longifolia, in this study, it can be acknowledged that the plant is not resistance to nickel stress, and is not suitable for phytoremediation and removing excess amounts of nickel in the environment. Also, due to the sensitivity of the plant to nickel stress, it can be counted as an indicator of environmental nickel pollution.

Soil pollution due to urban and industrial effluents containing heavy metals is one of the most serious environmental problems, and phytoremediation is a bio-cost-effective method for removing heavy metals from contaminated soil and water. In this regard, choosing the suitable plant for phytoremediation according to the type of pollution is very important. Since in addition to the amount of heavy metal absorption, the morphological and physiological characteristics of plants are also important in phytoremediation, an experiment was designed to investigate some morphological characteristics and fluorescence parameters of chlorophyll and the content of photosynthetic pigments of three plants including C. alternifolius, V. zizanioide and A. vera under two types of urban and industrial wastewater treatments. The results showed that urban and industrial wastewater treatments caused significant changes in all of the examined parameters. The interaction of wastewater and plant species on fresh weight of roots and shoots, dry weight of shoots, F0, Fm, Fv, chlorophyll a, b as well as Chlorophyll a+b were significant and for the other evaluated parameters were not significant. In general, based on this study, regarding the phytoremediation potential of the examined plants, it can be said that in soils polluted with urban wastewater, V. zizanioide and C. alternifolius and in soils polluted with industrial wastewater, V. zizanioide and A. vera were more effective.

The increase of the entry of industrial effluents containing various types of heavy metals into water and soil leads to the ever-increasing spread of environmental problems. Therefore, it is necessary to find less expensive solutions to reduce the pollution. In this regard, in order to compare the effect of the removal of heavy elements on some of the morphological and physiological characteristics of C. alternifolius, Ch. zizanioides and Aloe vera plants, an experiment was conducted in the form of a randomized complete block design with three replications for 14 months at the University of Guilan. The results showed that under the treatment of industrial wastewater, the metal accumulation indices (MAI) of zinc, chromium, lead, copper, manganese, nickel, magnesium were higher in Ch. zizanioides and Aloe vera than those in C. alternifolius. In all three studied plants, the indices of root length, shoot length, total biomass and tolerance index (TI) had a significant decrease compared with those in the control plants, and Ch. zizanioides and A. vera plants had the lowest percentage of decrease. In addition, other investigated components including absorption index (UI), total soluble sugar, total phenol content, total flavonoid, total anthocyanin, total tannin, and DPPH free radical inhibition percentage increased in all three plants under industrial wastewater treatment. The highest percentage of increase in all investigated components, except DPPH free radical inhibition percentage, was observed in Ch. zizanioides. In general, it can be said that in terms of MAI and morphological and physiological characteristics, Ch. zizanioides and A. vera were more successful than the C. alternifolius. Therefore, it is recommended to plant the studied plants in the order of priority (Ch. zizanioides ˃ A. vera ˃ C. alternifolius) in soils contaminated with industrial effluents, in order to remediate the soil.

Lead and cadmium are among the most important heavy metals which have entered the life cycle of the earth as a result of human activities.  In this study, in order to evaluate the ability of Indian mustard to uptake heavy metals (cadmium and lead), a survey was performed as randomized complete block design in which each metal was added  to the plant in four concentrations zero (a control), 50, 100 and 200 mg/kg soil. The results showed that the highest concentration of lead in the root and shoot (aerial parts) of Indian mustard was 278.4 and 61.8 mg/kg, respectively, in the 200 mg/kg treatment, while the highest amount of cadmium in these two organs was 14.5, and 10.9 mg/kg respectively in the treatment of 100 mg/kg soil. Also, with the increase of lead concentration in the soil, the amount of this element in Indian mustard increased linearly with a high correlation coefficient, and the bio-concentration coefficient of lead in the plant roots was greater than one in all studied treatments. Finally, it was found that Indian mustard can be used as a bio-indicator of lead and stabilized it in its root, but it is not able to stabilize or extract significant amounts of cadmium from soil.

Particulate matters are among the most important air pollutants in urban environment which cause heart and respiratory diseases. Plants play a major role in aerosol removal. In this study, some of important shrub species of urban green space were investigated for their ability of reducing air particulate matter pollutants.

In present study, effect of five shrub species (including privet, oleander, barberry, cotoneaster, Spindle tree), which most planted in Tehran city and their roles to aerosol sedimentation, was investigated. Therefore, leaf surface pollutants were collected and weighed and evaluated relative to the leaf surface.

The results showed that barberry collects pollutants more than other mentioned plants, while the efficiency of oleander is less than other species.

It seems that the morphology of plant leaves is effective in pollutant absorption. In addition, the amount of aerosol in air can affect the efficiency and absorption of suspended particles.

Although nickel is an essential element for plants, it has toxic effects at high concentrations. White clover (Trifolium repens) is a widely cultivated forage crop with high biomass. On the other hand, nickel pollution on farms has increased. Accordingly, in this study, the effects of nickel treatments (at 0, 10, 50, 100, 200, 500, and 1000 μM levels) were investigated on seed germination characteristics of the plant in a growth chamber and then on biochemical and physiological parameters in hydroponic culture, in a completely randomized statistical design. The results showed that seed germination, percent and speed, seed vigor, and seedling length increased and decreased with low and high levels of nickel, respectively. Seedlings' death was observed at 100 μM and higher concentrations of nickel. Concentrations of 10 and 50 μM of nickel harmed biochemical parameters including chlorophyll, carbohydrate, protein, and peroxidase activity and raised the amounts of carotenoids. By increasing levels of nickel treatments, roots, and shoots nickel concentrations increased. In comparison to the control, treatments of 10 and 50 μM nickel concentrations led to an increase and decrease in stem dry weight, shoot length, leaf area, and leaf dry weight, respectively. It seems that 10 μM and 50 μM concentrations of nickel function as suitable and toxic levels for the growth of this plant, respectively. It also seems that white clover is a nickel-sensitive plant and not able to tolerate and accumulate nickel, and it is not a proper candidate for phytoremediation.

Phytorefining is a sustainable, natural, eco-friendly and widely applicable method for refining heavy metals in soil. Heavy metals are dangerous environmental pollutants that enter the food chain and cause harm to humans, plants, and other organisms. The purpose of this research was to investigate the effect of zinc on the physiological stress process of spinach plants. Research

In order to investigate the effect of zinc element on the physiological stress process of spinach plant, a pot experiment was carried out in a factorial form and in the form of a randomized complete block design with three replications.

The results showed that increasing the concentration of chlorophyll b did not have a significant effect on chlorophyll b values, but caused significant changes in root and aerial parts, chlorophyll a, total chlorophyll and leaf surface.

According to the findings of the research, this plant can be used in soils contaminated with zinc metal or lands under the wastes of industrial factories to refine this metal.

Vetiver plant is from Poaceae family with high resistance, environmental compatibility and high ability for pollutants absorption, so can be used in environmental pollutions removal processes. Among petroleum compounds, polycyclic aromatic hydrocarbons are known as primary pollutants due to their stability in the environment. Phenanthrene usually has the highest concentration and most polluting among the petroleum aromatic compounds. In this study, vetiver was planted in pot with phenanthrene concentrations of zero (negative control), zero with acetone (positive control), 250, 500, 1000, 2000 and 4000 mg/kg soil dry weight and its physiological effects were investigated. At the highest concentration of phenanthrene the amount of chlorophyll and carotenoids decreased 20% and 21%, respectively, but phenolic compounds, proline and antioxidant activity were increased. Root and shoot weight at a concentration of 250 mg phenanthrene was significantly reduced compared to the control, but at subsequent concentrations, its decreasing slope was reduced. Root length and root volume also decreased. As phenanthrene is accumulated in root, so shows more decreases compare to shoot. Maximum accumulation of phenanthrene in vetiver root was 519 ppm in 4000 mg/kg soil dry weight phenanthrene concentration. Due to the resistance of vetiver to high concentrations of phenanthrene and its accumulation in roots, this plant can be used as a very suitable plant for the phytoremediation process of petroleum compounds.

To investigate the effect of soil application and foliar application of iron on growth indices and its ability to be absorbed by Mirabilis jalapa, an experiment was conducted in a completely randomized design with three replications in greenhouses located in the Golgohar iron ore mine in Kerman. Different levels of iron chelate used in this experiment included soil application (zero, 15, 30 and 90 mg kg-1 soil) and foliar application (2, 4 and 6 mg l-1 ). Soil application of iron chelate was initially tested with potting soil and foliar application was applied at the stage of stem and flowering. The results of this study showed that iron had a significant effect on the evaluated traits, so that the highest fresh and dry weight of shoots and roots, plant height, root length, chlorophyll a, b and total in soil iron treatment of 90 mg kg-1 it was observed that also the highest uptake of iron in shoots and roots was obtained in soil application of 90 mg kg-1 soil. In general, the results showed that the application of iron increased the growth indices and photosynthetic pigments of Mirabilis jalapa. Also, soil application of iron (90 mg kg-1 soil) had a better result than foliar application, on the other hand due to its ability to absorb iron by aerial parts and roots of this plant can also be used as a purifier of iron-contaminated soils.

Today, water pollution is a global challenge that, in addition to developing countries, is also present in developed countries. This global challenge is linked to economic growth, environmental health, and the health of billions of people. Water can be consumed by living organisms directly or indirectly by entering agricultural products, and the quantity and quality of life of living organisms, especially plants and humans, will suffer from serious problems. Today, agriculture is still recognized as the most important source of water pollution in the world and industrial activities are an important complement to this pollution. Various factors can cause water pollution, the most important of which are microbial, chemical, and heavy metal pollution. Heavy metals generally reduce the growth and yield of plants, and their effects on humans can lead to a variety of diseases, including cancer. Although prevention is the most important way to control water and heavy metal contaminants, there are several ways to remove them from the environment, one of the most important of which is phytoremediation. Phytoremediation is a type of bioremediation in which the plant is used to reduce the concentration or toxic effects of pollutants in the environment. This article reviews the types of heavy metals and their sources, the effects of heavy metals on humans and plants, and methods for repairing soils contaminated with heavy metals.

The use of ornamental plants in phytoremediation has attracted a lot of attention due to preventing the entry of heavy metals into the food chain and their beauty in the environment.  Today, tissue culture technique is used as a model system to predict the plants response to environmental pollutants. In the present study to investigate the ability of Narcissus tazetta L. in remediating the environment of cadmium contaminants, in vitro micropropagation of this ornamental plant was done by three procedures: induction, proliferation and bulb production. Then these plantlets were treated by cadmium chloride in three concentrations (1, 2 and 5 mM) in solidified MS culture medium for two weeks. The results showed that Narcissus plantlets are able to accumulate large amounts of cadmium and by increasing cadmium concentration in the medium, its accumulation in plantlets increases; So that in 5 mM treatment, the amount of cadmium in the roots, bulbs and leaves of plantlets was 7502.84, 1971.45 and 398.60 µg g-1DW, respectively. Increasing the concentration of cadmium in the medium caused a decrease in dry weight, amount of pigments, uptake of zinc and peroxidase activity.  In 1 mM cadmium chloride treatment the tolerance index was 0.95 that by increasing cadmium concentration, the tolerance of plantlets decreased. Transfer factor of plantlets were less than one and bioconcentration factor was more than one, indicating that Narcissus can be suggested as a suitable alternative for cadmium contaminant phytostabilization of course requires further research on the soil.

This study was conducted to evaluate the ability to grow and reduce water salinity by quinoa and wheat plants in greenhouse and hydroponic. This research was conducted in the form of a two-factor factorial experiment based on a randomized complete block design with three replications. The treatments included 4 salinity levels of zero (control), 5, 10 and 15 dS / m and two species of wheat and quinoa. In this study, traits such as total plant dry weight, accumulation of calcium, magnesium, sodium, potassium and total plant chlorine and the efficiency of water uptake by plants were measured. The results of this study showed that quinoa has more ability to absorb and accumulate elements than wheat and is a plant resistant to salinity stress. The results showed that the concentrations of sodium, chlorine and magnesium per plant (5.48, 10.12 and 1.12 g for wheat and 10.76, 11.65 and 2.66 g for wheat, respectively). Absorption efficiency of sodium, chlorine and magnesium from water (12.28%, 11.30% and 20.22% for wheat and 23.12%, 14.60% and 24.79% for quinoa, respectively). The results also showed that the amount of sodium, chlorine and magnesium accumulated in the plant and the efficiency of phytodesalination of sodium, chlorine and magnesium from saline water significantly increased with increasing in salinity for both wheat and quinoa. In the case of calcium and potassium bioaccumulation and phytodesalination efficiency decreased with increasing salinity. As a result, quinoa showed a significant bioaccumulation efficiency in dry weight production, compared to wheat, so it can be considered as an alternative plant for cultivation in salinity and dry climate conditions.

To avoid more environmental pollution, it is important to find an appropriate way to reduce the accumulation of heavy metals in metropolitan cities. The use of ornamental plants is a good choice to replace edible crops in soils of heavy metals contaminated. So, the purpose of this study was to evaluate the effect foliar application of humic acid (0, 250 and 500 mg/l) and cadmium application in different concentrations (0, 50 and 100 mg/kg) on growth and cadmium accumulation of sport turfgrass as a factorial experiment based on completely random design. The results showed that cadmium at 50 mg/kg concentration reduced growth characteristics. The growth of shoots was reduced at 250 mg/l of foliar application of humic acid. These results revealed that foliar application of humic acid can be used to remediate cadmium from soil in sport turfgrass. So, the humic acid at 500 mg/l concentration was achieved the highest amount of shoot cadmium accumulation from soil contaminated at 50 mg/kg cadmium concentration. According to the results of this experiment, since the amount of accumulation in mowed shoot was higher than others organs, this turfgrass can be recommended in phytoremediation of cadmium in contaminated areas with this metal.

One of the environmental problems is soil pollution with heavy metals from urban and industrial wastewater, and the treatment of these pollutants by plants is a cost-effective and environmentally friendly method. In this study, an experiment was conducted to evaluate the phytoremediation rate of Aloe vera in terms of metal accumulation index (zinc, chromium, lead, copper, manganese, nickel, magnesium, cadmium, mercury) and its morphological characteristics under two types of urban and industrial wastewater treatment. The design was completely randomized with three replications. The results showed that urban and industrial wastewater treatments caused significant changes (P≤0.05) in all examined parameters including leaf fresh weight, leaf dry weight, relative leaf water content, leaf length, leaf gel weight, the ratio of gel to leaf, root fresh weight, fresh plant weight, total biomass, root length, plant height, number of ramets, ramets height, ramets weight and root tolerance index in Aloe vera. The highest index of metal accumulation was observed in plants treated by urban wastewater and all the mentioned parameters showed a more significant decrease by treatment of urban wastewater than industrial wastewater. In the industrial wastewater treatment, all parameters decreased, but the average number of ramets increased compared to the control. In general, based on the parameters studied in this study, it can be said that the Aloe vera plant had better performance in soils containing industrial wastewater than in soils containing urban wastewater. IntroductionOne of the environmental problems is soil pollution with heavy metals from urban and industrial wastewater. Human activities such as the disposal of household waste and industrial activities mainly import heavy metals into the soil (European Commission, 2013; USEPA, 2021). Heavy metal pollution of soil can harm human life and the ecosystem through direct intake or entering the food chain (soil-plant-human or soil-plant-animal-human) (European Commission, 2013). Phytoremediation is a biological and cost-effective method to remove or reduce environmental pollutants. Some plants can remove, stabilize or transfer contaminants of soil or groundwater (Gajic and Pavlovic, 2018). Therefore, choosing a suitable plant for phytoremediation can be a crucial step in eliminating pollution based on region and type of pollution and expansion of urban wastewater.The province of Guilan, located in the north of Iran, has a humid subtropical climate and is a fertile province in terms of agriculture. The increased urban population in this province can cause pollution transfer into the river or land fields. This problem threatens the agricultural products of Guilan and causes a critical challenge. It seems that the cultivation of plants with high phytoremediation ability and the creation of a green belt in the landfill site of urban and industrial wastewaters is the most feasible and low-cost method to decrease the risk of soil and water pollution. In this study, we examined the ability of Aloe vera for phytoremediation of urban and industrial wastewater (UWW and IWW) and the possible alterations of, its morphological and physiological characteristics under wastewater pollution. Materials and Methods For this study, Aloe vera plants gathered from the local nursery were planted in the pots containing 11 kilos of soil suitable for A. vera cultivation. After a month of transferring the plants to the pots and adapting them to the new conditions, they were divided into three groups. Each group was irrigated for 14 months (every twice a week) with 300 mL of one type of solutions consideredas treatments for this experiment, including urban water (drinking water), UWW collected from the landfill site of Saravan, and IWW collected from the paper factory. Moreover, pots without plants were irrigated like pots with plants to determine the amounts of heavy metals (zinc, chromium, lead, copper, manganese, nickel and magnesium) after wastewater addition to the soil and compare it with maximum standard levels, pots with plants.Soil samples were homogenized and dried in an oven at 30°C for 24h and the concentration of heavy metals was determined. The relative water content (RWC) of leaves was measured before harvesting plants (Barrs and Weatherley, 1962). After harvesting the whole plants, leaf fresh weight, leaf length, leaf gel weight, ratio gel to leaf, root fresh weight, plant fresh weight, root length, plant height, number of ramets, ramets height, ramets weight, and tolerance index were measured. Leaf dry weight and total biomass were determined after drying plant tissues (oven 50 ºC for 72 hours). All dried plant tissues were turned into powder. Then the concentration of metal elements in plant samples was determined using ICP-OES based on the method of Salt et al. (1998) and Al-Oud Saud (2003).Metal Accumulation Index (MAI) was calculated using the following formula to determine the amount of metals accumulated in plants. (Liu et al., 2007):  Results and discussionComparison of means showed that urban and industrial wastewater treatments caused significant changes in all examined parameters, including the fresh weight of leaf, root, whole plant, and ramets, dry weight of leaf, length of leaf and roots, the height of plants and ramets, relative leaf water content, leaf gel weight, ratio gel to leaf, total biomass, number of ramets and root TI. The highest index of MAI was observed in plants treated by UWW, and the reduction of all mentioned parameters was more under treatment with UWW than IWW. Under the IWW treatment, all parameters decreased, but the average number of ramets increased compared to the control.Considering that MAI shows the overall performance of plants for co-accumulation of metal elements (Liu et al., 2007), A. vera was successful in accumulating Zn, Cr, Pb, Cu, Mn, Ni, and Mg. Previous studies have reported that plant species with a high MAI value should be used as barriers between contaminated and vulnerable areas, such as parks and residential areas (Nadgorska–Socha et al., 2017). It has been reported that high levels of metals in the soil inhibit various metabolic functions of plants and cause a delay in growth. The toxicity of heavy metals in different plants varies according to factors such as the type of plant, the bioavailability of metals, and the amount of metal displacement in the plant organs (Wang et al., 2006; Usman et al., 2005).The results indicate that an increase in the concentration of heavy metals probably decreases the amount of plant production, the size of the cells, and the dry weight of the organs. (Sharma and Dubey, 2005; Yadollahi et al., 2016). ConclusionAccording to MAI, morphological and physiological characteristics of the A.vera under UWW and IWW treatments, A.vera can be a good refining plant for cultivating and creating a green belt in contaminated soils. Due to the remarkable purifying ability of A.vera in removing heavy metals from contaminated soils, it is recommended to cultivate A.vera in areas polluted with industrial and urban wastewater to prevent the spread of pollution to the surrounding lands.  AcknowledgementThis article is extracted from the results of Sareh Ebrahimi Nokande’s Ph.D. thesis from the Faculty of Sciences, University of Mohaghegh Ardabili, Ardabil, Iran. The authors would like to thank University of Guilan for the technical supports.

Iron is an essential element in many physiological processes of the plant, but in high concentrations, it contaminates water and soil, which can be cleaned by using appropriate ornamental plants. In order to investigate the effect of iron heavy metal on growth indices and phytoremediation ability of Althaea rosea in a completely randomized design with three replications in greenhouses located in Golgohar iron ore mine in Kerman. The different levels of iron chelate used in this experiment were zero, 15, 30 and 90 mg/kg soil. Soil concentrations of iron chelate were initially mixed with potting soil. The results of this study showed that with increasing different levels of iron, growth indices and plant chlorophyll content showed a significant decrease, so that the highest fresh and dry weight of shoots and roots, plant height, root length, chlorophyll a, b and total was observed in the control treatment, also the highest iron uptake in shoots (1.84 ppm) and roots (1.56 ppm) was observed in the treatment of 90 mg/kg soil. In general, the results of this study showed that due to the ability to absorb iron in the tissues of this plant, ornamental Althaea rosea can be used for phytoremediation of heavy metal iron.

This study was conducted to investigate the combined and independent effects of drought stress and copper on vegetative traits (root length, stem length, fresh and dry weight of seedling), essential oil content and copper accumulation in roots, shoots and distilled plant material of Fumaria parviflora Lam. In this study, different concentrations of copper (control, 50, 150, 300 and 400 mg /kg) and different levels of drought stress (control, 50% and 75% based on soil moisture percentage discharge) on seeds collected from two mineral regions in Kerman province (Askari and Rabar) and in each region four zones (Z1, Z2, Z3 and Z4) were used. The results showed that in all treatments, the concentration of 50 (mg / kg) copper without drought stress (control) led to the highest value in terms of vegetative traits.The highest percentage of essential oil (0.45) in the treatment with concentration 150 (mg / kg) of copper and medium drought stress in zone 3 of Askari copper mine and the highest concentration of copper in roots, shoots and distilled plant material in treatment with 400(mg /kg) copper and severe drought stress in zone 3 of Askari mine were observed. In this study, the Cu remained in the plant tissue during the distillation process and the concentration of copper in the distilled plant material was almost similar to the concentration of plant shoots before the distillation process. The best treatment for f. parviflora cultivation in terms of plant essential oil, 150 (mg / kg) copper and medium drought stress was evaluatedthese findings support the use of F. parviflora as an acceptable species for soils that are in moderation contaminated with copper. behaviors such as slow growth and severe decline in biomass at high concentrations of Cu, it is concluded that the F. parviflora cannot be a candidate species for the phytoremediation of copper contaminated soil.

Having carcinogenic and toxic effects, aromatic hydrocarbons cause serious damage to the environment and living organisms. These compounds are mainly discharged into the soil. For the remediation of contaminated soils, biological methods utilizing the efficient microorganisms isolated from the oil-contaminated soils as well as resistant plants are preferred. The aim of this study was to assess the effect of Conocarpus erectus and Pseudomonas aeruginosa on the removal efficiency of polycyclic aromatic hydrocarbons (PAHs) from contaminated and saline soils of the salt separation pond of a desalination unit during 275 days under non-laboratory condition. The study was conducted in a factorial experiment with two factors based on completely randomized design with three replications. The factors used in this experiment included four treatment types (plant, bacteria, plant-bacteria cultivated in the soil, and soil with no plant and bacteria (control)) and the concentration of contaminant (Bangestan crude oil) with 5 levels (0, 0.5, 1, 2.5, and 5 wt%). As hydrocarbon concentrations increased at all five levels, the percentage of PAHs removal, the dry weight of roots and shoots, and chlorophyll contents decreased. At 0 and 1 % concentrations, the highest percentages of removal were obtained as 99.43, 59.89, and 57.01 for bacteria-plant treatment and separate bacterial and plant treatments, respectively (p≤0.05). The plant and the bacteria showed almost equal efficiency in the removal of oil hydrocarbons (p≤0.05). Bacterial treatments led to increased chlorophyll content as well as higher dry weight of roots and shoots compared with the treatments without bacteria (p≤0.05). Results indicated that individual treatments of plant and bacteria had a positive effect on the decomposition rate of PAHs. However, the rate was more positively influenced by the synergistic activity of the bacteria and plants (p≤0.05).

Soil contamination by industrial pollutants has associated with increasing risks for human, the environment and other living organisms. Cyanide is considered as one of the most toxic and dangerous pollutants used for the extraction of gold. One of the most cost-effective methods to eliminate cyanide from the environment and soil is "Phytoremediation". In this research, the Physiological and biochemical responses as well as remediation, and resistance of Sorghum bicolor to different cyanide treatments were investigated Accordingly, the effluent from the gold mining was prepared from Mouteh gold mining of Isfahan and this soil was mixed with normal soil to prepare different concentrations of contaminated soil. Cyanide changes in soil, total protein content, proline and morphometric Stem length, leaf, plant length and stem diameter changes of the plants were measured after completing the vegetative phase of the plant. Plant could absorb cyanide of contaminated soils, Total protein and proline content of the plant were enhanced with increasing cyanide content. Raising the cyanide contaminated soil resulted in promoted protein and proline content in treated plants,reduced cyanide concentration in soil and increased cyanide absorption by plant Sorghum. Plant could tolerate 12.69 g/kg of cyanide. Reduction of soil cyanide as well as its accumulation in plant and morphometric changes showed that phytoremediation is an appropriate method for the remediation of cyanide contaminated soils. Therefore, Sorghum bicolor can be a useful phytoremediation plant for removing cyanide from soils contaminated with these type of pollutants.