Phytoremediation 1 What is Phytoremediation Phytoremediation The process

Phytoremediation 1

What is Phytoremediation? • Phytoremediation : The process of removing contamination from soil or water using plants. • phyto = plant • remedium = restoring balance. 2

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Phytoremediation consists of mitigating pollutant in concentrations contaminated soils, water, or air, with plants 4

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Advantages of plants: Phytoremediation is cost effective. It is suited to remediation of large areas of soil. It is environmentally friendly. Phytoremediation sites are more aesthetically pleasing Phytoremediation sites are low maintenance. It involves no noisy and expensive equipment 6

Disadvantages Phytoremediation is limited to sites with lower contaminant concentrations. Toremediation is restricted to sites with contamination as deep as the roots of the plants being used. Not as effective for sites with high contaminant concentrations Phytoremediation is slower than conventional methods It does not work through the winter (Seasonally effective) The food chain could be adversely affected by the degradation of chemicals. The air could be contaminated by the burning of leaves or limbs of plants containing dangerous chemicals. 7

Phytoremediation The most important phytoremediation? 6 CO 2 + 6 H 2 O single act of C 6 H 12 O 6 + 6 O 2 8

How Does Phytoremediation Work? Plant roots take contaminants from the ground into the "body" of the plant. The plant root zone is referred to as the rhizosphere, this is where the action occurs. This soil supports large populations of diverse microorganisms. This is due to chemicals exuded by plant roots which provide carbon and energy for microbial growth. This combination of plants and microorganisms appears to increase the biodegradation of compounds. 9

This graphic shows a typical process diagram of phytoremediation. 10

Heavy metals • Arsenic Cadmium Lead Aluminum Beryllium Copper Iron Mercury Nickel These persist in soils and are toxic to animals even in small quantities

Various phytoremdiation processes 1. Phytoextraction or phytoconcentration, where the contaminant is concentrated in the roots, stem and foliage of the plant, 2. Phytodegradation, where plant enzymes help catalyze breakdown of the contaminantmolecule, 3. Rhizosphere biodegradation, where plant roots release nutrients to microorganisms which are active in biodegradation of the contaminant molecule, 4. Volatilization, where transpiration of organics, selenium and mercury run through leaves of the plant, 5. Stabilization, where the plant converts the contaminant into a form which is not bioavailable, or the plant prevents the spreading of a contaminant plume.

phytoremdiation Plants used to decontaminate soils must do one or more of the following: • Take up contaminants from soil particles and/or soil liquid into their roots, • Bind the contaminant into their root tissue, physically and/or chemically, • Transport the contaminant from their roots into growing shoots, • Prevent or inhibit the contaminant from leaching out of the soil. 14

Types of Vegetation Used Some of the plants used in phytoremediation are: • Alfalfa • Hybrid Poplar Trees • Blue-green Algae • Arrowroot • Sudan Grass • Rye Grass • Duck Weed • Bermuda Grass • Alpine Bluegrass • Yellow or White Water Lillies 15

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