Phytoremediation of heavy metal contaminated soils. Metal hyperaccumulation is a rare phenomenon that occurs in terrestrial plants. Processes include using plants that tolerate and accumulate metals at high levels phytoextraction and using plants that can grow under conditions that are toxic to other plants while preventing, for example, soil erosion phytostabilization. Accumulation of metals by roots in a hydroponic setup, followed by harvesting of the plant biomass is termed rhizofiltration dushenkov and kapulnik, 2000. Effect, mechanism, toxicity, and fate of chelating agents. Some plant species can take up heavy metals and concentrate them in their tissue. They can lead to accumulation of heavy metals in the soils of urban areas, which represents a serious threat to human and animal health. Metal phytoextraction metal phytoextraction is a branch of the concept of phytoremediation chaney, 1983 based on plants ability to work as a solardriven pump, extracting and concentrating particular elements from the environment. Role of mycorrhization in the phytoremediation of heavy. At the time of disposal, contaminants are typically concentrated in the much smaller volume of the plant matter than in the initially contaminated soil or sediment. Heavy metal contamination of soil is a major issue in the current scenario. But the slow growing and small biomass of most heavy metal accumulator species limit the use of hyperaccumulator plants for a large scale remediation. Phytoextraction, rumex dentatus, pbcontaminated soil introduction heavy metals occurrence in the soil, air, streams and food is an issue due to their detrimental effects on the health of human even at low concentration.
Role of phytoremediation in treating heavy metal pollution. Phytoremediation techniques and phytoextraction efficiency. Phytoremediation of heavy metal contaminated soils 3. As willow has some specific characteristics like high transport capacity of heavy metals from root to shoot,huge amount of biomass production, can use also for production of bio energy in the biomass energy power plant. Assisting phytoremediation of heavy metals using chemical. To date, over 400 plant species have been identified as natural metal hyperaccumulators, representing to treat the effluents under. These metals can enter into our body through consumption of foods, beverages, skin exposure and inhaled air. Some recommended plants which are commonly used in phytoremediation and. The application of chelating agents has shown positive effects in increasing the solubility of heavy metals in soil and therefore in enhancing phytoextraction. A number of metals including chromium, iron, arsenic, zinc, cadmium, mercury and copper are known to significantly compromise. New methods of cleaning up heavy metal in soils and water. Phytoextraction is a potential, innovative and costeffective technology for non destructive remediation of heavy metalcontaminated soils. The industry of mining and processing metals is a major source of farmland heavy metal contamination 26.
The phytoextraction of heavy metals from metalliferous soils. Such contaminants in waste water is one of the problems facing humans 1. This paper aims to compile some information about heavy metals of arsenic, lead. Evaluation of lead phytoremediation potential of rumex. Brooks rr 1998 plants that hyperaccumulate heavy metals their role in phytoremediation, microbiology, archaeology, mineral exploration, and phytomining. Chemically assisted phytoextraction of heavy metal. Phytoextraction of heavy metals a graphical representation.
Some metals, such as zn and cd, occur primarily in exchangeable, readily bioavailable form. It is further hypothesized that schizachyrium scoparium will be more effective at phytoextraction of heavy metals than pancium virgatum because schizachyrium scoparium was found growing along tar creek. Pdf heavy metals are considered as the major classes of a contaminant in nature. Heavy metals arsenic cadmium lead aluminum beryllium copper iron mercury nickel these persist in soils and are toxic to animals even in small quantities 12. It is grown either as a monoculture or in mixtures with kidney vetch anthyllis vulneraria and crimson clover. Due to their elemental character, hm cannot be chemically degraded, and their detoxification in the environment mostly resides either in stabilization in situ or in their removal from the matrix, e. Heavy metal phytotoxicity metals are natural components in soil. Phytoremediation is one of the safer, economical, and environmentfriendly techniques in which plants are used to recover polluted soils. Phytoremediation of heavy metal contaminated soil by. These species of plants have high tolerance to heavy metals and are capable of absorbing larger amount of metal in comparison.
Figure 2 shows a series of several revegetation test plots on the chat piles in galena, kansas. Only metals associated with fractions 1 and 2 above are readily available for plant uptake. Remediation options for soils contaminated with heavy metals 3. So far, two phytoextraction strategies have been developed. Phytoextraction has been growing rapidly in popularity worldwide for the last twenty years or so. Phytoremediation for heavy metal free download as powerpoint presentation. However, metal phytoavailability is a complex phenomenon that is dependent on a cascade of. Pdf phytoextraction of heavy metals from contaminated soil, water. The heavy metals such as cadmium, nickel, copper, zinc and lead from soil has been transferred to the shoots of the. Bioavailability depends on metal solubility in soil solution. The required time for soil cleaningup is usually 1015 years or longer. The plant tissues were also examined to see whether heavy metals.
For heavy metal phytoremediation and phytoextraction in pa rticular, bioavailability of metals in contaminated soils, is a crucial factor regulating heavy metal uptake by plant roots 5052. The effect of various extractants on the solubility of heavy metals in some soils was tested. Soils contamination by heavy metals and metalloids has become a serious environmental issue today. Another way plants can be used to clean up heavymetal contaminated soil is called phytoextraction. Typically, phytoextraction is used for heavy metals or other inorganics.
Contaminated soil was obtained from tar creek superfund site for this test. Heavy metal contamination from fertilizers, metal mining. There are a number of pollutant metals including iron, zinc, chromium, copper, arsenic, mercury and cadmium. Phytoextraction has emerged as a novel approach to clean up metalpolluted soils in which plants are used to transfer toxic metals from soils to shoots. Index termschromium, iron, phytoextraction, psoralea pinnata. Phytoextraction of heavy metals has garnered much attention in the past several decades since the initiation of its field trials, mainly conducted on important heavy metals, cadmium, and zinc usepa, 2000. The study is divided into three sections, bioavailability, phytomining, and phytoremediation. Heavy metal accumulation potential in the biomass and different plant parts of the selected species of energy crops cultivated on contaminated soil was evaluated. The phytoextraction of heavy metals from metalliferous soils a thesis presented in partial fulfilment of the requirements for the degree of doctor of. Phytoremediation mechanisms of heavy metal contaminated.
Finally heavy metal influence on biomass utilization possibilities. This study concerns the investigation of the potential use of plants to remove heavy metals, in particular nickel, zinc and cadmium, from soils. Phytoextraction is the use of plant to take up metal contaminants from soil through the absorption by plant roots. Although phytoextraction using hyperaccumulating plants is seen as a promising technique, a lack of understanding of the basic physiological, biochemical, and molecular mechanisms involved in heavy metal hyperaccumulation prevents the optimization of the phytoextraction technique and its further commercial application. The accumulation of metals in shoot tissue, followed by harvesting of shoot biomass, is called phytoextraction blaylock and huang, 2000. Among different heavy metals, chronic exposure to low doses of cancercausing heavy metals may induce many types of cancer. Pdf a method for remediation of soils contaminated with oil and heavy metals has been described. Certain plants called hyperaccumulators absorb unusually large amounts of metals in comparison to other plants. Phytodegradation and phytoextraction by hyperaccumulator plants are suitable methods to use in the remediation of soils with pollutant levels marginally above acceptable standards hortresearch, 2002. Chelatorenhanced phytoextraction of heavy metals from contaminated soil irrigated by industrial wastewater with the hyperaccumulator plant sedum alfredii hance yuebing sun a,b, qixing zhou a,c. Phytoextraction of heavy metals from sewage sludge by plants 29 soils, andor a good greenmanure crop. These metals displace the vital nutritional minerals from their original place, and hinder their biological function. It is hypothesized that both pancium virgatum and schizachyrium scoparium will be effective in the phytoextraction of heavy metals. Chelate assisted phytoextraction of heavy metals from soil.
Innovative approach to contaminated soil phytoremediation. Chelatorenhanced phytoextraction of heavy metals from. Phytoremediation for heavy metal treatment, bring you some principles. Cadmium and zinc, using alpine pennycress, a hyperaccumulator of these metals at levels that would be toxic to many plants. First place student essay phytoremediation of contaminated. Chemically assisted phytoextraction of heavy metal contaminated. Heavy metal phytoextraction by sedum alfredii is affected.
Heavy metals in the soil from anthropogenic sources tend to be more mobile, hence bioavailable than pedogenic, or lithogenic ones 19 24 25. Phytoremediation for heavy metal environmental issues. Processes include using plants that tolerate and accumulate metals at high levels phytoextraction. Phytoextraction is a subprocess of phytoremediation in which plants remove dangerous elements or compounds from soil or water, most usually heavy metals, metals that have a high density and may be toxic to organisms even at relatively low concentrations. For phytoextraction to occur, contaminants must be bioavailable ready to be absorbed by roots. The heavy metals that plants extract are toxic to the plants as well, and the plants used for phytoextraction are known. Nickel ni, has a special place between heavy metals, is a component of ni urease, unlike some heavy metals, and are required for some plant species in a small amount 0. Phytoextraction or phytoconcentration, where the contaminant is concentrated in the roots,stem and foliage of the plant, 2. Pdf accumulation of heavy metals hms in soil, water and air is one of the major environmental concerns worldwide, which mainly occurs. Phytoextraction potential, biomass yield and qualitative parameters of bioenergy plants grown on heavy metal contaminated soil has been measured. Phytoextraction phytoextraction, also called phytoaccumulation, refers to the uptake and translocation of metal contaminants in the soil by plant roots into the aboveground portions of the plants. Phytoremediation, and in particular phytoextraction, can be adopted in urban areas in order to remove harmful pollutants from the soil and to reduce the environmental footprint of urban activities. Pdf chelate assisted phytoextraction of heavy metals.
Recent techniques article pdf available in african journal of biotechnology 86. Phytoremediation of heavy metals from soils springerlink. Background information previous study in a previous study schizachyrium scoparium little bluestem and panicum virgatum switchgrass were tested for their ability to remove heavy metals from soil through phytoextraction. Phytoextraction of cadmium and zinc from a contaminated soil. Pollution by heavy metals hm represents a serious threat for both the environment and human health. It may be applied to metals such as zn, cd, ni, cu and pb. The lowcost, plantbased phytoextraction technique has often been described as a promising technique to remediate heavy metal contaminated agricultural land. Phytoextraction of metals and metalloids from contaminated.