Presentation Outline Traditional Engineering Solutions The - - PDF document

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The Phytoremediation of Heavy Metals using Mycorrhizae g y

Andrew Fraser and Evan Henrich

Presentation Outline

• Traditional Engineering Solutions
• Hyperaccumulation by plants
• Intro to mycorrhizae and Heavy Metals
• Analysis of recommended reading (study)
• Thoughts on practical application

Engineering Solutions

• Soil Excavation and Removal

– Pros

• Oldest method
• Causes the quick complete removal of the contaminant

– Con

• Merely moves contaminants elsewhere to be monitored

Merely moves contaminants elsewhere to be monitored

• Expensive
• Metal Fixation

– Pros

• Quick
• Less expensive then excavation
• Reduces health risks on site

– Cons

• Contaminate is still present
• Not necessarily non toxic, just less toxic

Chelates

• Makes metals more bioavailable to plants for

uptake

• Problem
• Problem

– Chemicals could leach into groundwater instead up uptaken

Hyperaccumulation

• The use of plants to

accumulate one or more toxic elements to extraordinarily high concentrations (i.e. 100x) compared to other i ( kk l vegetation (Bakker et al. 2000)

• Useful for As, Cd, Co, CU,

Pb, Mn, NI, Se, and Zn

• About 450 species have

been identified of doing this naturally (Bakker et al. 2000)

El Mehdawi & Pilon‐Smits (2012)

Thalspi caerulescens

• Small perennial plant
• Found in Western US,

Scandinavia, Europe

• Extremely effective in

Extremely effective in uptake up of heavy metals

• Slight problem‐ low

biomass, shallow roots, and slow growing

Image from Dr. Doty Phytoremediation power point

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Sebertia acuminata

• From New Caledonia,

archipelago 930 miles east of Australia

• Hyperaccumulates nickel‐

especially in leaves especially in leaves

• Sap is 10‐25% Ni on a

wet‐weight basis (Jaffre et al. 1976)

• Provides protection

against insects

Coppicing

• A traditional method of

woodland management

• Takes advantage of

trees making new

• Allow tree to grow, cut

to base, allow regrowth, repeat

• Effective with alders,

shoots when cut willows, oaks, birch

Background ‐ Mycorrhizae

What are they?

• Fine root – fungal

association

• Often symbiotic –

y exchange nutrients for carbon

• 90% of plants have

mycorrhizal connections

Background ‐ Mycorrhizae

Different Types? Arbuscular – fungal hyphae inside plant cell (96%) (vascular plants) Ectomycorrhizae fungal hyphae outside cell (3%) Ectomycorrhizae – fungal hyphae outside cell (3%) (Gymnosperms / Angiosperms)

Background – Mycorrhizae

• How are they different

from endophytes?

– Not bacteria – May have fruiting bodies y g (mushrooms) – Can actively transport nutrients / minerals to plant roots through hyphal network – Can only break down simple substrates

The Contaminants

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Zinc

Characteristics‐ Hard and brittle metal Commonly found with other base metals in ore Uses‐ Galvanizing, alloys, batteries, rubber catalysts, paint pigments, Health Effects‐ Lewis acid build up, Damage to nerve receptors‐ anosmia Lethargy, ataxia, hemolytic anemia Damage to liver, kidneys fungicides, nuclear reactors, fire retards Biologically: essential trace element for live. Deficiency can cause multiple health disorders‐ NIH 2001 Sources‐ Mining and smelting Industrial waste

Cadmium

Characteristics Soft malleable metal Water insoluble, if powdered and burned will release toxic fumes Use PVC stabilizers color pigments Health Effects Kidney damage and renal failure, skeletal damage, carcinogenic PVC stabilizers, color pigments, alloys, batteries, ancticorrosion agents, fertilizers Source Smelting, industrial emissions, agriculture, sewage, smoking, food

Lead

Characteristics Soft, malleable poor metal Use Building construction, batteries, ammunition, weights, alloys, radiation shielding, formerly paint pigment Health effects Harmful to many organs and tissues Interferes with development of the nervous system Symptoms – abdominal pain, f h d h pigment Source Paints, cooking implements, fuel emissions, smelters, industrial waste Potential exposure also from ingestion of contaminated, soil, dust or lead based paint, food or water confusion, headache, anemia, irritability, seizures, coma and death

Iron

Characteristic First transition metal Fourth most common element in Earth’s crust Uses Open a history book and look around you Health effects Overabundance ‐> free radicals = damages DNA, proteins, lipids Lethal dose‐ 60 milligrams per kilogram around you Trace element found in almost all life – proteins, enzymes especially hemes Source Meats, vegetables, mining, industrial waste

Background – Phytorem. Mkt.

• What are the needs for remediation of heavy

metals and how does phytoremediation fit in?

– Lots of heavy metal contamination (2 4 to 2 8 $bil / yr) (2.4 to 2.8 $bil / yr) – heavy metal often found co‐contaminated with

• rganics

($4.6 – 5.2 $bil / yr)

Background Phyto Rem Mkt

• When is Phytorem appropriate Tech?

– Accessible and static HM

• Contamination depth within reach of roots
• Ground / surface water pollution not imminent threat

Ground / surface water pollution not imminent threat

– Plants can survive / produce adequate biomass

• ver time
• Can plants survive HM and co‐contaminant levels?
• Can the plants uptake the heavy metals at a sufficient

rate over time?

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Effects of Endo‐ and Ectomycorrhizal Fungi on Physiological Parameters and Heavy Metals Accumulation of Two Species from the Family Two Species from the Family Salicaceae

• L. Mrnka et al

Experimental Design

• Pot experiment

– 8 incoculation treatments – 2 Salicaceae tree species (Willow and Poplar)

6 th d ti

• 6 month duration
• Initially weekly watering then water 2‐3x a

week after 8 weeks

• Randomized pot location every 4 weeks

Experimental Treatments

• AMI ‐ Glomus intraradices
• AMC ‐ G. claroideum
• EMH ‐ Hebeloma

mesophaeum

• EMP ‐ Paxillus involutus
• AMIC ‐ mixed AMI and

AMC

• EMHP ‐ mixed EMH and

EMP

• AMEM ‐ mixed AM and

EM

• CON ‐ control variant

Measured Parameters

• # of plants shoots‐ monthly
• Plant mortality‐ monthly
• Photosynthetic activity (Poplars only, measured twice)
• Photosynthetic pigments
• Leave spectroscopy
• Microscopy of root colonization‐ At harvest (250 tips a

plant)

• Assessment of biomass yield and heavy metals in

biomass (Fresh and dried weight, burned for metals)

The Study – Mortality Data

Table 1 Overview of mortality and inoculation success Clone S alix alba L. Populus nigra L. Treatment M SC FDM M SC FDM CON 3 4 – 1 9 – AMI 2 1

• G. intraradices

9

• G. intraradices

AMC 3 – 4 – AMIC 2 G intraradices 3 7 G intraradices AMIC 2

• G. intraradices

3 7

• G. intraradices

EMH 8

• H. mesophaeum

3 2

• H. mesophaeum

EMP 4 – 3 2 P . involutus EMHP 2 3

• H. mesophaeum

2 4

• H. mesophaeum

AMEM 3

• H. mesophaeum

2 8a

• H. mesophaeum, G. intraradices

The data are expressed as the number of replicates for the particular experimental treatment (willows and poplars are separate). The

• riginal number of replicates per treatment was 10. For explanation of the experimental treatments codes and fungal identities, see

Section 2 M mortality, S C successful colonization (i.e., the presence of at least one of the introduced fungal strains was confirmed in the given replicate; in CON treatment, no fungi were present), FDM fungi detected microscopically in the treatment replicates

aOnly two replicates were colonized by both fungal isolates, and the rest of the pots were colonized only by G. intraradices

The Study – Data (Total Uptake)

EMHP / AMEM – Willow

• 0.5x concentration of CON
• 2.5x biomass of CON

= 1.25x Uptake of CON

Table 3 Concentrations of heavy metals in shoots and leaves of S . alba L. and P . nigra L. HMs Cd Fe Pb Zn Clone Var Shoots Leaves Shoots Leaves Shoots Leaves Shoots Leaves S . alba CON 72.5±7.8a 81.7±4.7a 22.4±6.2a 61.5±9.4a 35.6±5.8a 4.1±0.9a 163.6±13.9a 412.9±42.5a EMH 39.8±8.2b 60.3±7.8a 10.7±2.0a 53.5±11.3a 20.2±4.4a 5.9±1.1a 108.8±20.8a 367.0±48.1a EMHP 38.7±6.8b 56.0±22.6a 9.8±1.0a 31.2±12.6a 16.9±3.2a 3.6±1.5a 108.3±5.1a 284.2±131.6a AMEM 35.0±3.2b 54.9±10.6a 9.7±1.8a 33.5±7.8a 19.7±2.2a 3.8±1.5a 109.6±4.4a 277.3±30.8a P . nigra CON 26.9±3.5x 33.7±2.2x 13.3±2.6x 22.8±3.3x 18.7±2.7x 6.6±0.7x 62.8±6.2x 177.5±8.7x EMHP 13.3±5.3x 28.2±5.6x 3.6±1.3y 16.0±4.9x 10.3±3.6x 6.8±1.8x 44.3±17.1x 199.3±47.7x AMI 22.3±3.4x 31.1±4.0x 21.8±5.7x 23.1±4.1x 29.3±5.4x 9.8±1.6x 65.0±9.8x 200.6±24.5x AMIC 22.0±4.0x 25.1±4.3x 15.0±2.0x 15.6±3.1x 21.6±3.4x 6.8±1.2x 63.2±5.6x 143.8±24.5x AMEM 19.6±1.2x 28.4±3.1x 14.0±2.1x 17.8±1.9x 19.8±1.6x 7.6±0.8x 65.8±4.5x 192.2±16.6x

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The Study ‐ Conclusions

• Different plant / fungi combinations work

better for different heavy metals

– Pb and Fe = Arbuscular Myco + Poplar – Zn and Cd = Ectomyco + Willow

• Mycorrhizal Fungi can ….

– Stunt growth = (poplar / arbuscular) – Promote growth = (willow / ecto)

• Connections are complex and challenging to

control!

The Study ‐ EH / AF Thoughts

– Contamination was a major problem

• Ectomycorrhizae took over most pots regardless of

where it started

– High mortality

• bad watering / weird storage and inoculating procedure

– Had to change watering regime mid‐experiment

• Altering conditions mid‐experiment affects results

– Sourcing of mycorrhizae was questionable

Conclusions – Practical Considerations

• Translocation of HM to aboveground biomass

allows for coppicing and removal from site

• Potential to use with shallow root

hyperaccumulators? hyperaccumulators?

• What will the impacts be of multiple

mycorrhizal connections per plant or per hyphal network?

Works Cited

• Slide show by Dr. Samuel Ma, Southern Illinois University. Available at

civil.engr.siu.edu/.../Phytoremediation%20for%20CE%20210‐DR_MA.pdf.

• Lecture Notes from ESRM 409 with R. Edmonds. Available at

http://www.cfr.washington.edu/classes.esrm.409/notes.htm

• Mrnka et al. “Effects of Endo / Ectomycorrhizal fungi on physiological parameters and heavy

metals accumulation of two species from the family salicaceae” Water, Air, and Soil Pollution (2012) 223: 399‐410. ( )

• Baker A.J.M., McGrath S.P., Reeves R.D., Smith J.A.C. (2000) Metal hyperaccumulator plants: a

review of the ecology and physiology of a biological resource for phytoremediation of metal polluted soils. In: Terry N., Ban˜ uelos G.S. (Eds), Phytoremediation of Contaminated Soil and

• Water. CRC Press, Boca Raton, FL, USA, pp 85–107.
• El Mehdawi A.F., Pilon‐Smits E.A.H., Ecological aspects of plant selenium hyperaccumulation

Sebertia acuminata: A Hyperaccumulator of Nickel from New Caledonia.

• Jaffré, R. R. Brooks, J. Lee and R. D. ReevesScience , New Series, Vol. 193, No. 4253 (Aug. 13,

1976), pp. 579‐580