Polytehnic University of Bucharest Faculty of Applied Chemistry

Polytehnic University of Bucharest Faculty of Applied Chemistry and Material Science Phytoremediation- the most effective method of remediating environmental factors using plants Coordinating teacher: Prof. Dr. Ing. Simina Daniela ȘTEFAN Student: Iuliana Adriana PREDOIU predoiu. iuli@gmail. com

Content: • I. Phytoremediation • II. How it works • III. Soil pollution • IV. Heavy metals • V. Different phytoremediation mechanisms • VI. Plants examples • VII. Advantages • VIII. Disadvantages • Bibliography

I. Phytoremediation • Phyto- plant • remedium- restoring balance defined as „the effecient use of plants for the remove, detoxify or immobilise environmetal contaminants in a growth matrix (soil, water, or sediments) through biological, chemical or physical plant activites and processes of the plants”

• Phytoremediation is an in situ remediation technology that utilises the inherent abilites of living plants. • The mechanisms and efficiency of phytoremediation depend on the type of contaminant, bioavailability and soil properties. • The root system provides an enormus surgace area that absorbs and accumulates the water and nutrients essential for growth, as well as other non-essential contaminants.

II. How it works? • Some plants are capable of removing or to descompose harmful chemicals from the ground when their roots take water and nutrients from contaminating soil, sediments and groundwater. • Plants can help clean contaminants as deep as their roots, which can go through natural processes to: § Depositing contaminants in roots, sterling or leaves; § Converted to less harmful chemicals in the plant or more frequently in the root area.

III. Soil pollution • Soil pollution is defined as the build-up in soils of persistent toxic compounds, chemicals, salts, radioactive materials, or disease causing agents, which have adverse of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons naphthalene and (such as benzo(a)pyrene), solvents, pesticides, lead and other heavy metals. The soil close to Yangzong Lake, soutwest China’s Yunnan Province was seriously polluted by Arsenic in 2009.

IV. Heavy metals are metallic chemical elements having atomic weight between 63. 54 and 200. 59, and a specific gravity greater than about 5. 0 g/cc. They are toxic, can damage living things at low concentrations and tend to accumulate in the food chain. The most common heavy metals contaminants are: As, Cd, Cr, Cu, Hg, Pb and Zn. Chronic problems associated with long-term heavy metals exposures are: • Arsenic – skin poisoning, and central nervous system • Cadmium – affects kidney, liver and GI tract. High levels of metals in soil can be phytotoxic. Poor plant growth and soil caused by mental toxicity can lead to metal mobilization in runoff water and subsequent deposition into nearby bodies of water. Furthermore, bare soil is more susceptibile to wind erosion and spreading of contamination by airbone dust.

V. Different phytoremediation mechanisms

VI. Plants examples • Many plants, such as mustard, alpine pennycress and gallop, have proven to be successful in over-contaminating contaminants at toxic waste sites. • Pennycress alpine Plant that has the role of tolerance and raising toxins in the soil. Can absorb high levels of cadmium and zinc from the soil. When compost is applied to contaminated soil, phytotoxicity decreases even more.

• For the decontamination of a lead-contaminated soil, a Brassica Juncea crop can be used with good results under the conditions of synthetic EDTAtype modifications. Lead concentrations in plant tissues are directly proportional to lead concentrations in the soil. Citric acid has the best ability to mobilize uranium from the soil and determine its absorption into Brassica juncea plant tissues.

• Citric acid has the best ability to mobilize uranium from the soil and determine its absorption into Brassica juncea plant tissues. The plants of the Arabidopsis family, Nicotiana tabacum, have good tolerance to metal ions, but especially to Zn.

VII. Advantages • Is less disturbing to the environment and does not involve waiting for new plant communities to recolonize the site • No storage space is required • Is more likely to be aesthetically accepted by the public than traditional methods • Avoid excavation and transport of polluted materials, thus reducing the risk of spreading contaminants.

VIII. Disadvantages • Slow growth and low biomass require a long-term commitment • Not possible to completely prevent the leaching of contaminants into the groundwater • The survival of the plants is affected by the toxicity of the contaminated land the general condition of the soil • Bio-accumulation of contaminants, especially metals, into the plants which then pass into the food chain, from primary level consumers upwards and/or requires the safe disposal of the affected plant material.

Bibliography: 1. „Phytoremediation: green techonology for the clean up of toxic metals in the environment”, Braz. J. Plant Physiol. Vol. 17 no. Londrina Jan/Mar. 2005 2. https: //homeopathtyler. wordpress. com/2010/06/18/phytoremediation-using-plants-to-remove-toxins/ 3. http: //www. unep. or. jp/Ietc/Publications/Freshwater/FMS 2/2. asp