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About: Phytoremediation is a(n) research topic. Over the lifetime, 8302 publication(s) have been published within this topic receiving 246842 citation(s).
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Journal ArticleDOI
TL;DR: Biological mechanisms of toxic metal uptake, translocation and resistance as well as strategies for improving phytoremediation are also discussed.
Abstract: Toxic metal pollution of waters and soils is a major environmental problem, and most conventional remediation approaches do not provide acceptable solutions. The use of specially selected and engineered metal-accumulating plants for environmental clean-up is an emerging technology called phytoremediation. Three subsets of this technology are applicable to toxic metal remediation: (1) Phytoextraction--the use of metal-accumulating plants to remove toxic metals from soil; (2) Rhizofiltration--the use of plant roots to remove toxic metals from polluted waters; and (3) Phytostabilization--the use of plants to eliminate the bioavailability of toxic metals in soils. Biological mechanisms of toxic metal uptake, translocation and resistance as well as strategies for improving phytoremediation are also discussed.

2,087 citations

Journal ArticleDOI
01 May 2013-Chemosphere
TL;DR: This review article comprehensively discusses the background, concepts and future trends in phytoremediation of heavy metals.
Abstract: The mobilization of heavy metals by man through extraction from ores and processing for different applications has led to the release of these elements into the environment. Since heavy metals are nonbiodegradable, they accumulate in the environment and subsequently contaminate the food chain. This contamination poses a risk to environmental and human health. Some heavy metals are carcinogenic, mutagenic, teratogenic and endocrine disruptors while others cause neurological and behavioral changes especially in children. Thus remediation of heavy metal pollution deserves due attention. Different physical and chemical methods used for this purpose suffer from serious limitations like high cost, intensive labor, alteration of soil properties and disturbance of soil native microflora. In contrast, phytoremediation is a better solution to the problem. Phytoremediation is the use of plants and associated soil microbes to reduce the concentrations or toxic effects of contaminants in the environments. It is a relatively recent technology and is perceived as cost-effective, efficient, novel, eco-friendly, and solar-driven technology with good public acceptance. Phytoremediation is an area of active current research. New efficient metal hyperaccumulators are being explored for applications in phytoremediation and phytomining. Molecular tools are being used to better understand the mechanisms of metal uptake, translocation, sequestration and tolerance in plants. This review article comprehensively discusses the background, concepts and future trends in phytoremediation of heavy metals.

2,047 citations

01 Jan 2000-
TL;DR: Why Use Phytoremediation?
Abstract: Why Use Phytoremediation? (B. Ensley). ENVIRONMENTAL POLLUTION AND GREEN PLANTS. Phytoremediation's Economic Potential (D. Glass). Phytoremediation and Public Acceptance (R. Tucker & J. Shaw). Regulatory Considerations for Phytoremediation (S. Rock & P. Sayre). TECHNOLOGIES FOR METAL PHYTOREMEDIATION. Phytoextraction of Metals (M. Baylock & J. Huang). Phytostabilization of Metals (S. Cunningham & W. Berti). Phytofiltration of Metals (Y. Kapulnik & S. Dushenkov). The Use of Plants for the Treatment of Radionuclide (M. Negri & R. Hinchman). Photostabilization of Metals Using Hybrid Poplar Trees (J. Schnoor). Phytoreduction of Environmental Mercury Pollution (C. Rugh, et al.). The Physiology and Biochemistry of Selenium Volatilization By Plants (M. de Souza, et al.). BIOLOGY OF METAL PHYTOREMEDIATION. Metal Accumulating Plants (R. Reeves & A. Baker). Mechanisms of Metal Hyperaccumulation in Plants (D. Salt & U. Kramer). Mechanisms of Metal Resistance: Phytochelatins and Metalothioneins (C. Cobbett & P. Goldsborough). Molecular Mechanisms of Ion Transport in Plant Cells (M. Guerinot).

1,614 citations

Journal ArticleDOI
TL;DR: The high metal accumulation by some cultivars of B. juncea suggests that these plants may be used to clean up toxic metal-contaminated sites in a process termed phytoextraction.
Abstract: A small number of wild plants which grow on metal contaminated soil accumulate large amounts of heavy metals in their roots and shoots This property may be exploited for soil reclamation if an easily cultivated, high biomass crop plant able to accumulate heavy metals is identified Therefore, the ability of various crop plants to accumulate Pb in shoots and roots was compared While all crop Brassicas tested accumulated Pb, some cultivars of Brassica juncea (L) Czern showed a strong ability to accumulate Pb in roots and to transport Pb to the shoots (1083 mg Pb/g DW in the roots and 345 mg Pb/g DW in the shoots) B juncea was also able to concentrate Cr{sup -6}, Cd, Ni, Zn, and Cu in the shoots 58, 52, 31, 17, and 7 fold, respectively, from a substrate containing sulfates and phosphates as fertilizers The high metal accumulation by some cultivars of B juncea suggests that these plants may be used to clean up toxic metal-contaminated sites in a process termed phytoextraction

1,368 citations

Journal ArticleDOI
Abstract: Metals including lead, chromium, arsenic, zinc, cadmium, copper and mercury can cause significant damage to the environment and human health as a result of their mobilities and solubilities The selection of the most appropriate soil and sediment remediation method depends on the site characteristics, concentration, types of pollutants to be removed, and the end use of the contaminated medium The approaches include isolation, immobilization, toxicity reduction, physical separation and extraction Many of these technologies have been used full-scale This paper will review both the full-scale and developing technologies that are available Contaminants can be isolated and contained to minimize further movement, to reduce the permeability of the waste to less than 1×10−7 m/s (according to US guidelines) and to increase the strength or bearing capacity of the waste Physical barriers made of steel, cement, bentonite and grout walls can be used for isolation and minimization of metal mobility Another method is solidification /stabilization, which contains the contaminants in an area by mixing or injecting agents Solidification encapsulates contaminants in a solid matrix while stabilization involves formation of chemical bonds to reduce contaminant mobility Another approach is size selection processes for removal of the larger, cleaner particles from the smaller more polluted ones To accomplish this, several processes are used They include: hydrocyclones, fluidized bed separation and flotation Addition of special chemicals and aeration in the latter case causes these contaminated particles to float Electrokinetic processes involve passing a low intensity electric current between a cathode and an anode imbedded in the contaminated soil Ions and small charged particles, in addition to water, are transported between the electrodes This technology have been demonstrated in the US full-scale, in a limited manner but in Europe, it is used for copper, zinc, lead, arsenic, cadmium, chromium and nickel The duration of time that the electrode remains in the soil, and spacing is site-specific Techniques for the extraction of metals by biological means have been not extensively applied up to this point The main methods include bioleaching and phytoremediation Bioleaching involves Thiobacillus sp bacteria which can reduce sulphur compounds under aerobic and acidic conditions (pH 4) at temperatures between 15 and 55°C Plants such as Thlaspi, Urtica, Chenopodium, Polygonum sachalase and Alyssim have the capability to accumulate cadmium, copper, lead, nickel and zinc and can therefore be considered as an indirect method of treating contaminated soils This method is limited to shallow depths of contamination Soil washing and in situ flushing involve the addition of water with or without additives including organic and inorganic acids, sodium hydroxide which can dissolve organic soil matter, water soluble solvents such as methanol, nontoxic cations, complexing agents such as ethylenediaminetetraacetic acid (EDTA), acids in combination with complexation agents or oxidizing/reducing agents Our research has indicated that biosurfactants, biologically produced surfactants, may also be promising agents for enhancing removal of metals from contaminated soils and sediments In summary, the main techniques that have been used for metal removal are solidification/stabilization, electrokinetics, and in situ extraction Site characteristics are of paramount importance in choosing the most appropriate remediation method Phytoremediation and bioleaching can also be used but are not as well developed

1,280 citations

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