Program One
Tuesday, May 20, 1997

Metals Kansa A


    8

IMPACT OF VEGETATION ON HEAVY METAL MOVEMENT

 
D. Zhu, A.P.Schwab, and M.K. Banks, Kansas State University, Manhattan, KS, 66506. Establishment of vegetation in mining areas is a primary method to minimize heavy metal contamination through wind erosion, runoff, and filtration. However, the influence of the plants on heavy metal downward movement to the ground water is not clear. This study was conducted to determine if plants will increase heavy metal leaching from mine tailings and heavy metal contaminated soil, and to evaluate the effect of two different grasses on heavy metal transport.

A small column experiment was conducted in the greenhouse beginning summer 1995. Six-inch-diameter PVC pipe was cut into desired lengths and filled with heavy metal-contaminated soil, mine tailings, and uncontaminated topsoil to mimic field conditions. Two grasses, tall fescue (Festuca arundinacea) and big bluestem (Andropogon gerardii ) were established In the columns.

The multilayered soil columns were leached with 0.001M CaCl2 solution with a proportioning pump under unsaturated conditions. The leachate was collected every 3 days. Cadmium(Cd) and zinc(Zn) in the leachate were analyzed using ICP (Inductively Coupled Plasma). Lead (Pb) was measured using graphite-tube AA. After one year, the plants were harvested, the columns were sacrificed, and heavy metal redistribution in the columns was investigated.

Both tall fescue and big bluestem increased Zn and Cd concentrations in the leachate, especially at about 2 months after the plants were established, possibly due to the active roots. However, plants did not increase Pb concentration compared to unvegetated control columns. Even though plants reduced the total amount of water leached, total Zn and Cd leached increased in the presence of the plants, while total Pb leached was positively correlated to total water solution collected from each column (r=0.8).

This study suggested that tall fescue and big bluestem may be used for Pb treatment, but it might be improper for Zn and Cd contamination treatment. Mine tailing remediation using the technology simulated in this study (covered with topsoil, with or without vegetation ) may reduce Pb contamination, but it may enhance Cd and Zn contamination.

Key words: vegetation, heavy metal leaching, column experiment, mine tailings



Top of Page


Return to Main Table of Contents
(to see full list of programs and abstracts)


Sub-Menu of Event Programs
(to see specific list of abstracts)


Tuesday, May 20, 1997

Metals Kansa A

Remediation of Munitions Compounds Kansa B

Analytical Methods Kansa C/D

General Topics Kansa B


Wednesday, May 21, 1997

Metals Kansa A

Zero-Valent Metals Kansa A

Remediation Kansa A

Vegetation-based Remediation Kansa B

Partnerships & Innovative Technologies Kansa C/D

Nonaqueous Phase Liquids Kansa C/D


Thursday, May 22, 1997

Biofilms & Barriers Kansa A

Bioremediation Kansa B

Partnerships & Technology Innovations Kansa C/D

Remediation Kansa C/D


Posters



Return to Publications Menu

[INDEX]

Send comments on the Great Plains/Rocky Mountain HSRC web pages to: hsrc@engg.ksu.edu;
comments or questions about this WWW server, to: www@engg.ksu.edu.