petroleum contaminated site at hickam air force base · 2011-08-10 · phytoremediation • the use...

Petroleum Contaminated Site at Hickam Air Force Base

Agriculture-Based Bioremediation of Petroleum Contaminated Soils

in Pacific Island Ecosystems

Greenhouse and Laboratory Studies Field Demonstration

Plant Study(C.S. Tang and W.H. Sun)

Microorganism Study(Francoise Robert)

Evaluation of Tropical Plants for Phytoremediation of

Petroleum Contaminated Coastal Subsurface Soils

in Hawaii

Presented by:Wenhao Sun

University of Hawaii

Phytoremediation

• The use of plant-based systems to remove, degrade or stabilize organic and inorganic contaminants in environments

– Low cost, aesthetically pleasing cleanup technique – Most useful at sites with shallow, low levels of

contamination– Useful for treating a wide variety of environmental

contaminants

Soil Background Depth(m)0

pH EC Salinity(mmhos/cm)

7.8

8.2

7.8

0.7-5.0 non -mdo.

5.0-30.0 mod.-high

8.2-10.0 mod.

1.3

1.8

Soil Background Depth(m)0

1.3 (51”)

1.8 (70”)

Petroleum USDA Hydrocarbons Classification

Sandy loamNo

No

< 3,500 mg/kg Sandy loam

Silt

Objective

• Evaluate tropical plants for use in phytoremediation of petroleum contaminated coastal deep soils

Tasks and Technical Approach

• Plant selection– Preliminary screening of plants for

tolerance of salt and petroleum hydrocarbons

– Main screening of plants for reduction of petroleum hydrocarbons

• Simulating petroleum-contaminated deep soil using trisector-planters

Key Experimental Components-Preliminary screening

• Objective– Identify the plants with high tolerance to either NaCl or No. 2

diesel fuel

• Materials and Methods– Plant materials: Nine plants grown in DeepotTM

– Treatment: Control: without NaCl and DieselSalt level: 2% NaClDiesel levels: 5,000 mg/kg

10,000 mg/kg

Criteria for Plants Used in Field Demonstration and Evaluation

Experiments–Native or naturalized

–Salt tolerant

–Deep Rooting

–Wide potential and range of use

–Rapid growth

–Low maintenance

Plant Species Used• Trees (5 species)

- Kiawe Prosopis pallida- Milo Thespesia populnea- Kou Cordia subcordata- Common ironwood Casuarina epuisetifolia- Tropic coral tree Erythrina variegata

•Shrubs (3 species)- False sandalwood Myoporum sandwicense- Beach naupaka Scaevola sericea- Nerium oleander Nerium oleander

•Grass (1 species)•Buffelgrass Cenchrus cilliaris

Plants Used in Field Demonstration

Kiawe Milo

Kou Common ironwood

Plants Used in Field Demonstration

Tropical coral tree False sandalwood

Beach naupaka Nerium oleander

Growth Conditions

• Two to five-month old plants transplanted to Deepots (6.35 x 25.4 cm)

• Top soil, coral sand/sandy loam• Greenhouse conditions

– 55% shaking, misting for two weeks– Temperature range: 36/19 C (Day/Night)– Light intensity: Max. 600 µmol m-2 s-1

– Sub-irrigation with Peter’s liquid nutrients containing 0% or 2% NaCl


• Evaluation– Plant growth (plant height and biomass)

Milo

Control 2% NaCl 5,000 mg/kg 10,000 mg/kgDiesel Diesel

Kou


Common ironwood


Nerium oleander


Tropical coral tree


Buffelgrass


Kiawe



• Results– Tropical coral tree, buffelgrass and kiawe

seedlings were susceptible to either 2% of NaCl or diesel fuel at 10,000 mg/kg soil, but tolerant of diesel at 5,000 mg/kg.

– Milo, Kou, common ironwood, N. oleander, beach naupaka and false sandalwood were tolerant of high salinity (2% NaCl) and high diesel fuel level (10,000 mg/kg).

Key Experimental Components-Main screening

• Objective– select trees and shrubs that have a high potential

to remediate saline soil contaminated with petroleum hydrocarbons using No.2 diesel fuel as a model contaminant.

• Materials and Methods– Plant materials: Seven plants selected from preliminary

experiment.– Treatment: Diesel levels: 0 (mg diesel/kg soil)

5,00010,000

Salt level: 1% NaCl


• Evaluation– Photochemical efficiency– Plant biomass– Diesel concentration in soil

Plant Effects on Diesel Depletion In Soil Treated with 5,000 mg diesel /kg soil

No plant

No plant c

ontroOlea

nderNau

paka

NaioIro

nwoodKouMilo

Kiawe

TPH

-D (m

g/kg

)

0

2000

4000

6000

8000

10000

Day 0 14 Weeks

Plant Effects on Diesel Depletion In Soil Treated with 10,000 mg diesel/kg soil

No plant

No plants

Oleander

Naupak

aNaio

Ironwood

Kou

MiloKiaw

e

TPH

-D (m

g/kg

)

0

2000

4000

6000

8000

10000

Day 0 14 Weeks

** *


• Results– Milo, kou and kiawe significantly accelerate

degradation of petroleum in the soil containing both 10,000 mg /kg diesel and a moderate salinity (1% NaCl).

Key Experimental Components-Trisector planter experiment

• Objectives– Determine the feasibility of accelerating the degradation of

petroleum contaminants in coastal deep soils using selected plants.

• Materials and Methods– Plant materials: Milo, kou and false sandalwood– Treatment: Plants vs. unplanted Control

Aeration vs. non-aeration– Apparatus: Trisector-Planter – Soil treatment: Spiked with 6 petroleum hydrocarbons in

the bottom section.

The trisector planter with a growing tree and a soil profile similar to that of the field demonstration site.

Aeration device In the bottom section

Trisector Planter Experiment

• The bottom sandy loam was spiked with diesel components of known concentrations

Hydrocarbon Concentration (mg/kg of soil)Hexadecane 500Eicosane 500Docosane 500Pristane 200Phenanthrene 200Pyrene 200

False sandalwood Milo Kou(Left front)

Key Experimental Components-Trisector planter experiment

• Evaluation– Quantitative analysis of the 6 petroleum

hydrocarbons

Statistical significance of changes in the concentration of 6 petroleum hydrocarbons in the bottom section of unplanted trisector-planters between day 0 and day 200 by t-tests.

_________________________________________________________Hydrocarbon t-test significancea

_________________________________________________________Hexadecane NSEicosane NSDocosane NSPristane *Phenanthrene *Pyrene **_________________________________________________________

aNS, not significant; *, significant (P < 0.05); **, significant (P 0.01).

Statistical significance of changes in the concentration of 6 petroleum hydrocarbons in the bottom sections of aeration treatment vs. non-aeration control at day 200 by t-tests.

_________________________________________________________Hydrocarbon t-test significancea

_________________________________________________________Hexadecane NSEicosane NSDocosane *Pristane NSPhenanthrene NSPyrene NS_________________________________________________________

aNS, not significant; *, significant (P < 0.05).

Reduction of PHC (%)Compared to unplanted control

-20

0

20

40

60

80

100He

xade

cane

Eico

sane

Doco

sane

Phen

anth

rene

Pyre

ne

False sandalwoodMiloKou

SummaryEvaluation Process and Results

Buffelgrass

Nerium oleanderNerium oleander

Beach naupakaBeach naupaka

False sandalwoodFalse sandalwoodFalse sandalwood

KouKouKouTropical coral tree

MiloMiloCommon Ironwood

Kou

MiloCommon Ironwood

KiaweMilo

Kiawe

Recommend-ed plants

Trisector-planterMain-screeningPre-screening

Conclusions

• Milo and kou have better potential than false sandalwood in phytoremediation of petroleum in the costal subsurface soils in Hawaii and other Pacific Islands.

Conclusions

• The trisector-planter designed for deep soil phytoremediation study can serve as a useful tool to indirectly but convincingly validate the effectiveness of phytoremediation in the field.

Acknowledgements• Principal Investigators (UH):

Chung-Shih TangFrancoise Robert Chittaranjan Ray

• Research Associate: Marisa Toma

• Graduate Research Assistants: Ryan Kody Jones, J.B. Tay

• Undergraduate Research Assistants:Monroe Bryce, Jim Leary, Matthew Vierra, and Joey Lo

• Sponsor: CH2M HILL Inc.

Mahalo

petroleum contaminated site at hickam air force base · 2011-08-10 · phytoremediation • the use...

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