Phytoremediation of an Arsenic-Contaminated Site Using Pteris vittata L.: A Two-Year Study

Abstract

A field study was conducted to determine the efficiency of Chinese brake fern (Pteris vittata L.), an arsenic hyperaccumulator, on removal of arsenic from soil at an arsenic- contaminated site. Chinese brake ferns were planted on a site previously used to treat wood with chromated copper arsenate (CCA). Arsenic concentrations in surface and profile soil samples were determined for 2000, 2001, and 2002. In both 2001 and 2002, senesced and senescing fronds only, as well as all fronds, were harvested. Frond arsenic concentrations were not significantly different between the three harvests. Compared to senesced fronds, live fronds resulted in the greatest amount of arsenic removal. There were no significant differences in soil arsenic concentrations between 2000, 2001, and 2002, primarily due to the extreme variability in soil arsenic concentrations. However, the mean surface soil arsenic was reduced from 190 to 140 mg kg⁻¹. Approximately 19.3 g of arsenic were removed from the soil by Chinese brake fern. Therefore, this fern is capable of accumulating arsenic from the CCA-contaminated site and may be competitive, in terms of cost, to conventional remediation systems. However, better agronomic practices are needed to enhance plant growth and arsenic uptake to obtain maximum soil arsenic removal and to minimize remediation time.

KEY WORDS:

• arsenic
• chromated copper arsenate
• Pteris vittata L.
• phytoextraction
• hyperaccumulation

ACKNOWLEDGMENTS

This research was partially supported by the National Science Foundation (Grants BES-0086768 and BES-0132114). The authors gratefully acknowledge Mr. Thomas Luongo for analytical and field support and Ms. Heather Williams for her invaluable assistance with field sampling.

Notes

∗The 2002 data are normalized to estimate for the entire year's harvests. Values represent means ± std dev.

∗The 2002 data are normalized to estimate for the entire year's harvests. Values represent means ± std dev.

∗Values represent means ± std dev.