Arsenic species in an arsenic hyperaccumulating fern, Pityrogramma calomelanos: a potential phytoremediator of arsenic-contaminated soils

Sci Total Environ. 2002 Feb 4;284(1-3):27-35. doi: 10.1016/s0048-9697(01)00854-3.

Abstract

The fern Pityrogramma calomelanos is a hyperaccumulator of arsenic that grows readily on arsenic-contaminated soils in the Ron Phibun district of southern Thailand. P. calomelanos accumulates arsenic mostly in the fronds (up to 8350 microg As g(-1) dry mass) while the rhizoids contain the lowest concentrations of arsenic (88-310 microg As g(-1) dry mass). The arsenic species in aqueous extracts of the fern and soil were determined by high performance liquid chromatography coupled to an inductively coupled plasma mass spectrometer (HPLC-ICPMS) which served as an arsenic specific detector. Only a small part of the arsenic (6.1-12%) in soil was extracted into water, and most of this arsenic (> 97%) was present as arsenate. The arsenic in the fern rhizoids was approximately 60% water-extractable, 95% of which was present as arsenate. In contrast, arsenic in the fern fronds was readily extracted into water (86-93%) and was present mainly as arsenite (60-72%) with the remainder being arsenate. Methylarsonate and dimethylarsinate were detected as trace constituents in only two fern samples. Preliminary estimates of phytoremediation potential suggest that P. calomelanos might remove approximately 2% of the soil arsenic load per year. With due consideration to the type of arsenic compounds present in the fern, and their water-solubility, the option of disposing high arsenic ferns at sea is raised for discussion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arsenic / analysis
  • Arsenic / chemistry
  • Arsenic / pharmacokinetics*
  • Biomarkers
  • Chromatography, High Pressure Liquid
  • Environmental Pollution / prevention & control*
  • Ferns / chemistry*
  • Plant Roots / chemistry
  • Soil Pollutants / analysis
  • Soil Pollutants / pharmacokinetics*
  • Solubility
  • Tissue Distribution

Substances

  • Biomarkers
  • Soil Pollutants
  • Arsenic