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

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 μg As g-1dry mass) while the rhizoids contain the lowest concentrat...

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Bibliographic Details
Main Authors: Kevin Francesconi, Pornsawan Visoottiviseth, Weeraphan Sridokchan, Walter Goessler
Other Authors: Syddansk Universitet
Format: Article
Published: 2018
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Online Access:https://repository.li.mahidol.ac.th/handle/123456789/20170
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Institution: Mahidol University
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Summary: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 μg As g-1dry mass) while the rhizoids contain the lowest concentrations of arsenic (88-310 μg As g-1dry 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. Copyright © 2002 Elsevier Science B.V.