جستجوی مقالات مرتبط با کلیدواژه "آلودگی خاک" در نشریات گروه "اکولوژی"

Phytoremediation is a kind of natural and sustainable technique, easy, low-cost, eco-friendly, environmentally friendly and applicable in wide areas, in which resistant plants are used to purify soils contaminated with organic and mineral compounds. This research was carried out with the aim of evaluating the phytoremediation ability of tree species  such as Locust tree (Robinia peseudoacacia L.), Elm tree (Ulmus carpinifolia var umbraculifera Rehd.), Tree of Heaven (Ailanthus altissima) and Judas tree (Cercis siliquastrum) in soils contaminated with lead and cadmium heavy metals in Eynak Wetland in ​​Rasht. For this aim in polluted sites and controlled site, Considering the main wind direction, one Transect is selected and sampling from leaves and surface roots was done with statistical method in completely randomized plot design with three replicates. Then lead and Cadmium content density in each samples was determined by Atomic absorption instrument model Perkin-Elmer 3030.Results indicated that the concentration of lead and cadmium in polluted sites tree more than the control sites. Also Locust tree, Tree of Heaven and Judas tree species have the highest translocation factor of Lead (0.59 ppm, 0.56 ppm, 0.19 ppm) and Cadmium (0.56 ppm, 0.38 ppm, 0.19ppm) respectively. According to this issue and appropriate adaptation conditions, these species can be widely used in Phytoremediation projects of soils contaminated with lead and cadmium under the same conditions.

Heavy metals enter the environment directly and indirectly with the development of various industries of metal smelting, mining, and chemical industries. Physical and chemical methods of soil purification from heavy metals are used due to high costs and less time-consuming. Phytoremediation is a low-cost and relatively fast solution to soil pollution and increases biodiversity, reduces erosion, and increases soil fertility. In this study, the phytoremediation potential of the Camelina plant in removing heavy metals Pb and Cd from soil was investigated. The experiment was conducted in a completely randomized design with Cd (0, 3, 5, and 10 mg/kg) and Pb (0, 100, 300, and 600 mg/kg) treatments with 3 replications in the greenhouse of Razi University in Kermanshah. The results showed that with increasing the concentration of Pb and Cd, the accumulation of these elements in the roots of the Camelina plant increased significantly. Most soil biological properties at the highest concentrations of Cd and Pb were significantly reduced compared to the control. The high concentration of Pb and Cd in the roots of the plant and the low transfer factor of these elements, indicate the greater efficiency of this plant for use in plant stabilization techniques, and we cannot be used to extract heavy metals lead and cadmium from soil.

Ethiopian (Brassica carinata) and Indian (B. juncea) mustards from Brassicacea are important oily crops. Ethiopian mustard with a deep root system is resistant to drought and heat and Indian mustard is a promising plant for metal phytoremediation. Accordingly the potential for the absorption, tolerance and remedation of lead (Pb) by these species grown in contaminated soils were investigated. Plants were grown in greenhouse in soils contaminated with 15, 300 and 600 mg kg-1 of Pb, harvested after 7 weeks and analyzed for parameters including length, dry weight, leaf area, photosynthetic pigments and Pb concentration. Both species had great stress tolerance indices to Pb. Furthermore, Pb treatments did not significantly affect root and shoot lengths, dry weights and specific leaf area in both mustards. Although photosynthetic pigments in Ethiopian mustard remained unaffected by Pb treatments, the contents of chlorophylls and carotenoids decreased in 600 mg kg-1 Pb treatment in the Indian mustard. Root Pb concentrations of both Ethiopian and Indian mustard significantly increased with rise in lead contamination, so that the ratio of Pb concentration of root to soil (bioconcentration factor) increased. Pb concentration in the shoot of Ethiopian mustard was significantly increased in 600 mg kg-1 of Pb, which this amount in the control and treatment of 600 Pb was 7 and 30 mg kg-1, respectively. However, there was no significant change in other treatments. Both plants displayed low translocation factor for Pb. Thus, with regards to biomass, stress tolerance indices, high Pb concentration in root and thereby, high bioconcentration factors both Ethiopian and Indian mustards can be useful in phytostabilization Pb contaminated soils and remediation of these soils in urban and industrial areas.

Heavy metal pollution in soil is one of the major environmental problems throughout the world. Since metals uptaken by plants and fruits are transferred to humans, this problem is more serious in agricultural and garden soil. The object of the present study was to investigate and assess heavy metals in vineyards soil of Malayer plains. Random sampling system was used in this study. Totally, 25 soil samples were collected from the depth of 0-20 cm. Soil samples were analyzed by HR-CS AAS with flame method. The mean concentrations of Copper, Lead, and Zin in the soil samples were 7.36, 6.91, and 54 mg/kg respectively which were lower than the world average and earth crust for these metals. The results showed that positive and significant correlation between Cu - Zn, Cu - Pb, Zn - Pb and pH – EC. It seems that in addition to geology and parent materials, chemical fertilizers and animal manure are the sources of metals to vineyrads soil. In addition, copper fungicides have not played any role in the increase of the concentration of copper with regard to the application of sulphur as fungicide. At present these heavy metals are serious risk for these vineyard soils.

The so-called phytoextraction in which hyperaccumulator plants are used to remediate the contaminated soils is proven to be an efficient method. The objective of this study was to investigate the capability and efficiency of spinach for phytoremediation of cadmium from Cd-contaminated soils. For this purpose, a completely randomized design with five treatments including 0, 15, 30, 60 and 120 mg Cd/ kg soil and three replications was established in natural conditions. After contaminating the experimental soils with different levels of cadmium, the seeds of spinach were planted. When plants were fully developed, plants were harvested and their cadmium contents in shoots and roots as well as the soil-cadmium were measured. The results indicated that by increasing Cd concentration in soil, the most Cd accumulation was occurred in the roots rather than shoots. Maximum cadmium concentration within the shoots and roots was 73.7 and 75.86 mg.kg 1 soil, respectively. According to spinach ability to absorb high concentration of cadmium in the root zone and its high biomass and capability of cadmium accumulation in shoots, this plant can be used as a hyperaccumulator to remediate cadmium from Cd-contaminated soils. But, according to minimum remediation time and maximum dry matter for the 30 mg Cd/ kg soil, maximum Cd extracted by shoots in hectare/year was in 30 mg Cd/ kg soil. It can be concluded that spinach is a suitable plant for phytoremediation of slight to moderately cadmium contaminated topsoils.

Climate change, especially an increase in CO2 concentration and soil pollution due to heavy metals, has changed plant growth and metal uptake by them. This research was carried out in order to investigate the impacts of increasing atmospheric CO2 concentrations on Fe, Cu and Zn uptake and the growth parameters of wheat and sorghum at two levels of CO2 (400 and 900 μL L-1) and four levels of cadmium (0. 10, 2 and 40 mg kg-1). After 60 days, the plants were harvested, and the results showed that increasing CO2 concentration led to significantly increased plant height, leaf area, root and shoot dry weight (p< 0.01). Increasing CO2 concentration caused increase concentration and uptake of Cd, Fe, Cu and Zn in sorghum shoot and root. In contrast, uptake of these elements in wheat decreased. Among nutrients, the greatest increase in concentration for shoots of sorghum was in Zn (14-25%) and in root was related to Fe (16-25%). For wheat, Cu showed the greatest decrease in concentration in shoot (19-25%) and root (10-15%). Decreasing the uptake of Cd in wheat can be a factor for higher stress tolerance but, on the other hand, a decrease in micronutrient concentrations, especially of Zn, in crops such as wheat that has been used widely, can create problems associated with plant growth conditions and food production. For sorghum, although an increase in the uptake of nutrients was seen, increased Cd uptake is a problem that must be noted within the context of human and food safety.

Remediation of heavy metals polluted soils by physical and chemical methods requires large investments and complicated technologies. Phytoremediation is a relatively new technology that employs plants to decontaminate soils، water، sediments and atmosphere. This technology، compared to other technological approaches، is an environmental-friendly، easy to use and inexpensive method. Modeling Phytoremediation process is needed for further understanding the governing process and also to manage the contaminated soils. The objective of this study was to present a macroscopic phytoremediation model for of Ni-Polluted Soil. For this purpose، a new formulation was derived based on soil and plant responses to Ni pollutants. This approach assumes that relative yield reduction function can resemble the total Ni concentration in the soil. Combining the related functions of soil and plant responses to soil Ni concentrations، the phytoremediated amounts of Ni were predicted. In order to verify the proposed models، large quantities of soil was thoroughly polluted with Ni. After achieving soil and pollutants equilibrium، the contaminated soils were then carefully packed into pots. Upland Cress (Lepidum sativum) seeds were germinated in these pots. The Ni of soil samples and plant materials were extracted by 4M HNO3 oxidation and wet oxidation methods، respectively. Ni concentrations in the soil extracts and plant digestion were measured by Atomic Absorption Spectrometer (Shimadzu، AA 670-G) and Inductively Coupled Plasma Optical Emission Spectrometry (Varian Vista-PRO). The results indicated that relative yield reduction function followed a non-linear reduction trend. The results indicated that the proposed model for quantifying Ni concentration in plant can simulate the experimental data well (R2>0. 93(. The results also indicated that combining the non-linear relative yield reduction function and the proposed power model for Ni concentration in plant، provides a reasonable performance to predict Ni phytoremediation (R2>0. 93).