evaluating phytoremediation of lead-contaminated soils in
Post on 12-Jun-2022
4 Views
Preview:
TRANSCRIPT
Evaluating Phytoremediation of Lead-Contaminated
Soils in Lo‘i Agriculture
Ryan Ueunten
Master’s of Environmental Management, NREM
Capstone Panel: Dr. Susan Crow, Dr. Creighton M. Litton, Dr. Noa Lincoln
1
Motivation - Lo‘i Agriculture
Irrigated pondfieldKalo
(taro, Colocasia esculenta)
“Huli ka lima i lalo”
(Turn hands downward)
2
Motivation - Lead (Pb) Contamination in Soil
● Lo‘i agriculture in degraded areas
● Pb toxicity
● Contaminated kalo and soil
3Students planting in loʻi
Background - Phytoremediation
● “Intentional cultivation of plants to clean
contaminated environments” (Tangahu
et al. 2011)
Uptake through roots
Pb2+ contaminants
Contaminant storage
in biomass
Phytoextraction
Translocation through
shoots
● Phytoextraction
4
Capstone Objective
Results can assist kalo farmers, cultural practitioners, and community members
“Assess if phytoremediation is a potential solution for
remediating soil Pb contamination in lo‘i agriculture.”
5
Research Questions
1. Which plants are more effective at uptaking bioavailable Pb in lo‘i soils?
2. Which parts of each plant (roots or shoots) accumulate the most Pb?
3. How many rounds of phytoremediation are needed to reduce soil Pb concentrations
to a safe level?
6
Approach - In situ Experiment
7
● Ulupō heiau
○ Kailua, O‘ahu
○ Pohakupu silty clay loam (Fine, parasesquic, isohyperthermic Oxic Humustepts)
○ Non-profit organization:
○ Former dumping site
Trash found in lo‘i site
● Three phytoremediation plantings
Indian Mustard (Brassica juncea)
● Widely studied plant
● 8 weeks of growth
8
‘Ae‘ae (Bacopa monnieri)
● Native wetland plant
● Not well studied
● 5 months of growth
9
Control Plants
● Mix of weedy species
● 8 weeks of growth
PC:
https://www.wildflower.org/plants/result.php?id_plant=LUOC
Nutsedge
(Cyperus rotundus)
Honohono grass
(Commelina diffusa)
Mexican primrose
(Ludwigia octovalvis)
10
A1 Control
A3 ‘Ae‘ae
A4 ‘Ae‘ae
A5 Control
A6 Control
A7 Indian Mustard
A8 Indian Mustard
A9 Indian Mustard
A2 ‘Ae‘ae
Approach - Experimental Layout
● 3 lo‘i plots per planting
Indian Mustard
Control
11
‘Ae‘ae
Collect post planting
soil samples
Collect plant biomass
samples
4Plant the plants!
2Collect pre planting
soil samples
1
Approach - Experimental Design
Remove plants
3
12
Results - Biomass Growth per Day
13
● Most growth = Control plants
● No surprise
● Poor drainage
b
b
b
a
b
b
● Highest Pb conc. = ‘Ae‘ae roots
(Tukey HSD Test; P < 0.001)
14
Results - Biomass Pb Concentrations
Results - Total Pb Uptake per Day
15
ab
b
a
● Pb uptake = biomass growth × Pb conc.
● ‘Ae‘ae > Indian mustard
(Tukey HSD Test; P < 0.001)
○ Roots
● Flooded conditions (reduced)
○ ⬆ redox potential = ⬆ mobile
Pb
● Control?
Results - Soil Pb Concentrations
● No differences
● ⬆ spatial variability?
● ⬇ sampling intensity?
● ⬆ immobile Pb
● 0.1-2.2% bioavailable Pb
(Huang et al. 1997;
Bouquet et al. 2017)
16
Results - Estimated Rounds of Phytoremediation
● Safe soil level = 0-75 mg/kg Pb
● 1,000-120,000 rounds
● 100-18,000 years
17
Discussion - Is Phytoremediation Effective?
● Best candidate = ‘Ae‘ae
18
‘Ae‘ae biomass and sample
○ Native plant!
● Overall, not practical
● Mobile Pb vs Immobile Pb
● Need other methods
PC: https://horriem.com/back-to-the-drawing-board-great
Discussion - Alternative Methods
● Try other plants
● Adding chelating agents
○ Increase bioavailable Pb
● Deploying microbes
● Soil Removal + Phytoremediation
19
Collecting biomass samples
PC: Jordan Gestrich
Acknowledgements
1. University of Hawai‘i Mānoa, CTAHR
○ Dr. Susan Crow, Dr. Noa Lincoln, Dr. Creighton Litton
○ Dr. Rebecca Prescott
○ Amazing peers
2. Hau‘oli Mau Loa Foundation
3. Kauluakalana
4. Friends and family
20
Mahalo!Questions?
21
ReferencesTaro Security and Purity Task Force (TSPTF). 2009. E ola hou nā kalo; ho‘i hou ka ‘āina lē‘ia Taro security and purity task force 2010. Legislative report.
Honolulu, HI.
Bremer L, Faliniski K., Ching C., Wada C., Burnett K., Kukea-Shultz K, Reppun N., Chun G., Oleson K., Ticktin T. 2018. Biocultural restoration of traditional
agriculture: cultural, environmental, and economic outcomes of lo‘i kalo restoration of He‘eia, O‘ahu. Sustainability. 10(12): 4502.
Handy E. & Handy E. 1991. Native planters of old. Bishop Museum Press. Honolulu, HI.
Levin P. 2015. Ch.4 Lessons from the taro patch, in Thinking like an island. University of Hawai‘i Press. Honolulu, HI.
Kagawa-Viviani A., Levin P., Johnston E., Ooka J., Baker J., Kantar M., Lincoln N. 2018. I ke ēwe ‘āina o ke kupuna: Hawaiian ancestral crops in perspective.
Sustainability. 10(12): 4607.
Beckwith M. 1970. Hawaiian Mythology. University of Hawai‘i Press. Honolulu, HI.
Kurashima N., Fortini L., Ticktin T. 2019. The potential of indigenous agricultural food production under climate change in Hawaiʻi. Nature Sustainability. 2:191–
199.
Ladefoged T., Kirch P., Gon S., Chadwick O., Hartshorn A., Vitousek P. 2009. Opportunities and constraints for intensive agriculture in the Hawaiian archipelago
prior to European contact. Journal of Archaeological Science. 36: 2374–2383.
Levin P. 2015. Ch.3 Searching for sustainable agriculture in Hawai‘i, in Thinking like an island. University of Hawai‘i Press. Honolulu, HI.
Evans D. 2008. Taro mauka to makai. 2nd edition. College of Tropical Agriculture and Human Resources. 22
ReferencesCho J., Yamakawa R., Hollyer J. 2007. Hawaiian kalo, past and future. College of Tropical Agriculture and Human Resources. Sustainable Agriculture. 1: 1-8.
Hawai‘i State Department of Health (HDOH). 2017. Final Lead in Soils Fact Sheet.
Sutherland R. and Tolosa C. 2001. Variation in total and extractable elements with distance from roads in an urban watershed, Honolulu, Hawaii. Water, Air, and
Soil Pollution. 127: 315–338.0.
Dixit R., Wasiullah, Malaviya D., Pandiyan K., Singh U., Sahu A., Shukla R., Singh B., Rai J., Sharma P., Lade H., Diby P. 2015. Bioremediation of heavy metals
from soil and aquatic environment: an overview of principles and criteria of fundamental processes. Sustainability. 7: 2189-2212.
Hawai‘i State Department of Health (HDOH). 2018. New guidelines: Childhood lead poisoning Prevention.
Islam S., Kashem A., Osman K.T. 2016. Phytoextraction efficiency of lead by arum (Colocasia esculenta L.) grown in soil. International Journal of Soil Science.
11(4): 130-136.
Tangahu B., Abdullah S., Basri H., Idris M., Anuar N., Mukhlisin M. 2011. A review on heavy metals (As, Pb, and Hg) uptake by plants through
phytoremediation. International Journal of Chemical Engineering. 2011:1-31.
Henry J. 2000. An overview of the phytoremediation of lead and mercury. National Network of Environmental Management Studies. Prepared for: U.S.
Environmental Protection Agency.
Jabeen R., Ahmad A., Iqbal M. 2009. Phytoremediation of heavy metals: physiological and molecular mechanisms. Botanical Review. 75(4): 339-364.
23
ReferencesSalido A., Hasty K., Lim J-M., Butcher D. 2003. Phytoremediation of Arsenic and Lead in Contaminated Soil Using Chinese Brake Ferns (Pteris vittata) and Indian Mustard
(Brassica juncea). International Journal of Phytoremediation. 5(2): 89-103.
Huang J., Chen J., Berti W., Cunningham S. 1997. Phytoremediation of lead contaminated soils: role of synthetic chelates in lead phytoextraction. Environmental Science
Technology. 31(3):800-805.
Bouquet D., Braud A., Lebeau T. 2017. Brassica juncea tested on urban soils moderately contaminated by lead: Origin of contamination and effect of chelates. International Journal
of Phytoremediation. 19(5): 425-430.
Hue N. 2013. Arsenic chemistry and remediation in Hawaiian soils. International Journal of Phytoremediation. 15(2): 105-116.
Paquin D., Campbell S., Li Q. 2004. Phytoremediation in Subtropical Hawaii - A Review of Over 100 Plant Species. Remediation Journal. 14(2): 127-139.
Sinha S. 1999. Accumulation of Cu, Cd, Cr, Mn, and Pb from artificially contaminated soil by Bacopa monnieri. Environmental Monitoring and Assessment. 57: 253-264.
Prescott R. 2018. Preliminary soil Pb concentrations of Ulupō site. Unpublished raw data.
Natural Resources Conservation Service (NRCS), US Department of Agriculture (USDA). 2019. Web Soil Survey. http://websoilsurvey.sc.egov.usda.gov/.
United States Environmental Protection Agency (USEPA). 1996. Method 3050B: acid digestion of sediments, sludges, and soils. Revision 2. Washington, DC.
R Core Team. 2020. R: A language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria. https://www.R-project.org/.
Oviedo C. & Rodriguez J. 2003. EDTA: The chelating agent under environmental scrutiny. Quim. Nova. 26(6): 901-905.
24
top related