This reflects light on the effects of Heavy metals on the contaminated soil & how to over come the ill effects by phyto remediation..or use of plants in reclaiming the soil...

5. Sources of heavy metal in the environment Municipal and Industrial waste Sediment from wastewater treatment plant

6. Leachate from solid waste treatment plant Mining wastes

9. Heavy metals prevailing in soil and their regulatory limits Source – Salt et al ( 1995 ) Elements Conc. Range (mg/kg) Regulatory limit (mg/kg) Lead 1-6900 600 Cadmium 0.1-345 100 Arsenic 0.1-102 20 Chromium 0.005-3950 100 Mercury 0.001-1800 270 Copper 0.03-15500 600 Zinc 0.15-5000 1500

15. Application of Phytoremediation

17. Soil Remediation (Schnoor, 2002) Application Description Contaminants Types of Plants Phytotransformation Sorption, uptake, and transformation of contaminants Organics, including nitroaromatics and chlorinated aliphatics Trees and grasses Rhizosphere Biodegradation Microbial biodegradation in the rhizosphere stimulated by plants Organics; e.g., PAHs, petroleum hydrocarbons, TNT, pesticides Grasses, alfalfa, many other species including trees Phytostabilization Stabilization of contaminants by binding, holding soils, and/or decreased leaching Metals, organics Various plants with deep or fibrous root systems Phytoextraction Uptake of contaminants from soil into roots or harvestable shoots Metals, inorganics, radionuclides Variety of natural and selected hyperaccumulators, e.g., Thalaspi,

18. Water/Groundwater (Schnoor, 2002) Application Description Contaminants Types of Plants Rhizofiltration Sorption of contaminants from aqueous solutions onto or into roots Metals, radionuclides, hydrophobic organics Aquatic plants, (e.g., duckweed, pennywort) Brassica, sunflower Hydraulic Control Removal of large volumes of water from aquifers by trees Inorganics, nutrients, chlorinated solvents Poplar, willow trees Phytovolatilization Uptake and volatilization from soil water and groundwater; conversion of Se and Hg to volatile chemical species Volatile organic compounds, Se, Hg Trees for VOCs in groundwater; Brassica, grasses, wetlands plants for Se, Hg in soil/sediments Vegetative Caps Use of plants to retard leaching of hazardous compounds from landfills Organics, inorganics, wastewater, landfill leachate Trees such as poplar, plants (e.g., alfalfa) and grasses

19. . . . . Phytoremediation can occur through a series of complex intereactions between plants, microbes, and the soil, including accumulation, hyperaccumulation, exclusion, volatilization, and degradation. Plants also stabilize mobile contaminated sediments by forming dense root mats under the surface.

21. Hyper-accumulators Plants, so called hyperaccumulator s are usually used, they take up 100 times the concentration of metals over other plants

24. Important and widely reported hyper accumulators used for metal remediation ELEMENTS Plant species Max. reported Conc . ( mg/kg) Cadmium Thlaspi caerulescens 500 Cupper Ipomoea alpina 12300 Cobalt Haumaniuastrum robertii 10200 Lead Thlaspi rotundifolium, Brassica juncea, Zea mays 8200 Nickel Alyssum lesbiacum, Sebertia acuminata 47500 Zinc Thlaspi caerulescens Brassica juncea, B. oleracea, B. campestris 51600 Selenium Brassica juncea, B. napus 900 Chromium Brassica juncea, Halianthus annus 1400

31. Costs * Jonathan Chappel 1997 Contaminant Phytoremediation Other Technologies Source Metals $80 per cubic yard $250 per cubic yard Black (1995) Site contaminated with petroleum hydrocarbons (site size not disclosed) $70,000 $850,000 Jipson (1996) 10 acres lead contaminated land $500,000 $12 million Plummer (1997) Radionuclides in surface water $2 to $6 per thousand gallons treated none listed Richman (1997) 1 hectare to a 15 cm depth (various contaminants) $2,500 to $15,000 none listed Cunningham et al. (1996)

41. Thank You..