Application of Vetiver Grass in the Treatment of Lead-Contaminated Community Garden Soil

Zhiming Zhang

Rupali Datta

Roley Noffke

Dibyendu Sarkar

2

Pb Contamination in Urban Soils

Pb-containing paint

Leaded gasoline

Pb dosage in urban soils

(Residential;

Community Garden)

Banned in 1978 in U.S.

Banned in 1996 in U.S.

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Pb Contamination: Human Health Implications

Bickel, M. J. (2010). Spatial and temporal relationships between blood lead and soil lead concentrations in Detroit, Michigan. Wayne State University.

Fair D. (2015). Issues of The Environment: The Dangers of Lead in Washtenaw County. https://www.wemu.org/post/issues-environment-dangers-lead-washtenaw-county

Johnson & Bretsch. (2002). Soil lead and children’s blood lead levels in Syracuse, NY, USA. Environmental Geochemistry and Health, 24, 375-385. https://doi.org/10.1023/A:1020500504167

Laidlaw et al. (2017). Case studies and evidence-based approaches to addressing urban soil lead contamination. Applied Geochemistry, 83, 14-30. https://doi.org/10.1016/j.apgeochem.2017.02.015

Mielke et al. (2007). Nonlinear association between soil lead and blood lead of children in metropolitan New Orleans, Louisiana: 2000–2005. Science of the Total Environment, 388(1-3), 43-53. https://doi.org/10.1016/j.scitotenv.2007.08.012

Zahran et al. (2011). Nonlinear associations between blood lead in children, age of child, and quantity of soil lead in metropolitan New Orleans. Science of the Total Environment, 409(7), 1211-1218. https://doi.org/10.1016/j.scitotenv.2010.11.036

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Soil Pb Remediation

Pb Remediation in Soil

Soil Extraction;

Washing/leaching;

Replacement

in situ

ex situ

Electro-remediation

Chemical immobilization

Microbial immobilization

Phytoremediation

…

Large expense (~$1.6 million per acre feet in New Jersey), ecological disruption, and other regulatory issues

Dependent on many environmental factors such as pH, redox, water content, chemical availability, etc.

Use of plants to absorb and translocate lead to above ground tissues which are harvested and removed

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Phytoremediation of Pb using Vetiver Grass (Chrysopogon zizanioides)

Mature Vetiver Root

6-mo old Vetiver

• High tolerance for metals
• Fast growing
• High biomass
• Non-Invasive. Sterile, doesn’t produce seeds.
• Perennial grass
• Massive complex root system
• Tall and dense shoot system
• Reduces soil erosion
• Survives in different types of soils (pH 3 -10; EC up to 8 dS/m)
• Survives in a wide range of climates (55^oC to -10^oC)
• Easy to maintain once established

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Phytoextraction

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Chemically Catalyzed Phytoremediation for Soil-Pb Removal

EDDS*

EDDS

7

San Antonio, TX

Jersey City, NJ

Pb Mobilization by EDDS

8

Pb Phytoremediation in Community Garden

Community garden with active Pb input

Vetiver Treatment Plot: Vetiver + EDDS

Vetiver Control Plot: Vetiver + No EDDS

Bermudagrass Control Plot: Bermudagrass + No EDDS

Zhang et al. (2023). Chemically Catalyzed Phytoextraction for Sustainable Cleanup of Soil Lead Contamination in a Community Garden in Jersey City, New Jersey. Sustainability, 15(9), 7492. https://doi.org/10.3390/su15097492

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Changes in Pb Concentration

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Changes in Pb Existing Forms

F1: water-soluble Pb

F2: exchangeable Pb

F3: carbonate-bound Pb

F4: oxide-bound Pb

F5: organic-bound Pb

F6: residual silicate-bound Pb

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Pb Accumulation in Plant Root and Shoot

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Examples of Pb Phytoremediation in Residential Properties

San Antonio, TX

Jersey City, NJ

13

Field Study Design

14

San Antonio, TX

Jersey City, NJ

Field Test Results after First Round of EDDS Application

15

Summary

EDDS*

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Thank You!

Acknowledgement:

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This work was supported by a Lead Technical Studies grant (#MILTS0007-17) from the U.S. Department of Housing and Urban Development.

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We are grateful to Maria Rozier for providing the study site and for maintaining plant growth in the community garden. Frances Levy is acknowledged for helping with field study and laboratory sample analysis. We thank Roley Nöffke for presenting our research in ICV-7.