Trees in Phytoremediation
Grete Gansauer
BZ 572
November 29, 2012
Outline
 Why trees make good phytoremediators
 Species currently used in phytoremediation
 Pollutant clean up and methods
 Organic Remediation
 Inorganic Remediation
 Some Case Studies
 Capturing Economic Value from projects
Why trees are awesome
 They *can* grow fast
 And use a lot of water (high transpiration
rates)
 They are large
 Their root systems are also large and deep
 Large, microbially diverse rhizosphere
 Potential for ecological restoration
 They are woody
 They grow in bad places
 They are perennials
 Their products have economic value
Tree species used for remediation
 Riparian tree species are
 Poplar
common
 Willow
 Genipa americana
 Mulberry
 Legumes
 Eucalyptus
 Evergreens?
 High transpiration and
water uptake rates
 Fastest growers
 Clean up pollution in water
 Not used for merchantable
timber
Species of Acacia accumulate Cadmium
Ornamental Mulberry
Methods of Tree-remediation
 Stabilization
 Rhizofiltration*
 Riparian Buffer Strips
 Extraction*
 Volatilization*
 Stimulation
 Degradation
 Detoxification
Riparian Buffer Strip in Wisconsin
Historical and Current Uses of Trees in
Phytoremdiation
 Use of trees in Phytoremediation since the early 1990’s
 Organic pollutant clean up:
 TCE, TNT, PAH, MTBE
 Inorganic pollutant clean up:
 Cr, Cd, Pb, Zn
 Phytoremediation in conjunction
with Biomass Fuels production
Willow being grown on contaminated
land for biomass production
Trees and Organic Remediation
 TCE
 Poplar volatilization, stabilization, stimulation
 Naphthalene
 Eucalyptus rhizodegradation
 MTBE
 Poplar hybrids
 Pines
 PAH
 Mulberry
Using Eucalyptus to remediate Naphthalene
Trees and Metal Remediation
 Potential for accumulation & phytoextraction
 Cadmium
 Willow
 Legumes (Acacia, Mimosa, Anadenantera)
 Genipa americana
 Lead
 Eucalyptus
 Legumes
 Mangrove
 Chromium
 Genipa americana
Genipa americana and Cr
 South American Rainforest Species
 Phytostabilization and Rhizofiltration of two
harmful Cr ions
Chromium in action
 Rhizofiltration of Cr3+ on roots
 Phytostabilization of Cr6+
 Cr6+ converted to Cr3+ in plant
 Adsorbed Cr on roots, but did
not translocate Cr to the shoot
 Cr lowered PS rate
 Lower K concentration in leaves w/ Cr
 Riparian Buffer potential?
 Rhizofiltration of Zn and Cd as well
Genipa americana
Meanwhile, in Europe…
 Phytoextraction and Biomass Fuels
Production
 Short-Rotation Coppice Willow plantations
 Biomass plantations on former agricultural
land (contaminated?)
 Irrigated with waste water
Trees are harvested every 3-5 years
Willows being irrigated with industrial wastewater
Willow coppice regeneration.
Phytoextraction with Salix viminalis
 Concentration of Cd in willow-planted
soil was 12% lower than control soil
(field study)
 Willow-planted soils had “significantly
higher Carbon”
 Microbial stimulation potential?
 Negligible difference in soil pH
 Willows in alkaline soils accumulated the
most Cd
Willows planted on former
agricultural land near a
wastewater treatment plant.
 High irrigation rates…even with waste
water!
 High accumulation of Zn and Cd in
willow leaves
 Removed 5% Zn and 20% Cd from the
soil (greenhouse study)
Biomass Biproducts
 Metals accumulated in
shoot, shoot harvested
for fuel
 Burned in a Fluidized
Bed Reactor
 Metals not combusted,
still found in ash
 Don’t re-scatter
contaminated ashes onsite for fertilizer!
Questions!
 What are two reasons that trees good candidates for
phytoremediation?
 Name one Tree species I mentioned and how it can be used
for phytoremediation.
References
1.
Arnold, C.W. 2007. Phytovolatilization of oxygenatied compounds from gasoline-impacted groundwater at an underground storage tank site via conifers.
International Journal of Phytoremediation. Vol. 9, iss. 1. pp. 53-69.
2.
Aronsson, P. & Perttu, K. 2001. Willow vegetation filters for wastewater treatment and soil remediation combined with biomass production. Forestry Chronicle,
Vol. 77 iss. 2. pp 293–299
3.
Barbosa, Rena Mirian T. et al. 2007. A physiological analysis of Genipa americana: a potenital phytoremediator tree for chromium-polluted watersheds.
Environmental and Experimental Botany. Vol. 61, iss. 3. pp. 264-271.
4.
Burken, J.G. 1996. Hybrid poplar tree phytoremediation of volatile organic compounds. Americal Chemical Society. Vol. 212. pp. 106-110.
5.
Dimitriou and Ioannis et al. 2012. Changes in organic carbon and trace elements in the soil of willow short-rotation coppice plantations. Bioenergy Res. Vol. 5.
pp
563-572.
6.
Hong, M.S. 2001. Phytoremediation of MTBE from a groundwater plume. Environmental Science. Vol. 35 iss. 6. pp. 1231-1239.
7.
Klang-Westin, E. & Eriksson, J. 2003. Potential of Salix as phytoextractor for Cd on moderately contaminated soils. Plant and Soil, Vol. 249, iss. 1. pp 127–
137.
8.
Ma, X.X. 2004. Phytoremediation of MTBE with hybrid poplar trees. International Journal of Phytoremediation Vol 6., iss. 2. pp 157-167.
9.
Peng, X.C. 2012. Lead tolerance and accumulation in three cultivars of Eucalyptus urophyllaXEgrandis: implication for phytoremediation” Environmental Earth
Studies. Vol. 67, iss. 5. pp. 1515-1520.
10.
Pereira, A.C.C. 2012. Heavy metals concentration in tree species used for revegetation of contaminated area”. Revista
43, iss. 4. pp.
641-647.
11.
Santana, Kaline B. et al. 2012. Physiological analyses of Genipa americana reveals a tree with ability as phytostabilizer and rhizofilter of chromium ions for
phytoremediation of polluted watersheds. Environmental and Experimental Botany. Vol. 80. pp 35-42.
12.
Souza, V.L. et. al. 2010. Morphophysiological responses and programmed cell death induced by cadmium in Genipa americana (Rubiaceae). Biometals. Vol. 24. pp:
59-71
13.
Stomp, A.M. et al. 1993. Genetic improvement of tree species for remediation of hazardous wastes. Tissue Culture Association, In Vitro Cell Division of
Biology. Vol. 29. pp 227-232.
14.
Syc, Michael et al. 2012. Willow trees from heavy metals phytoextraction as energy crops. Academy of Sciences of Czech Republic Journal of Biomass and
Bioenergy. Vol. 37. pp 106-113.
15.
Xingmao, M. et al. 2004. Phytoremediation of MTBE with hybrid poplar trees. International Journal of Phytoremediation. Vol. 6, iss. 2. pp 157-167
Ciencia Agronomica. Vol.