Format

Send to

Choose Destination
See comment in PubMed Commons below
Environ Sci Technol. 2005 May 1;39(9):3359-67.

Thermal treatment of metal-enriched biomass produced from heavy metal phytoextraction.

Author information

  • 1Ecole Polytechnique Fédéral de Lausanne, ENAC--ISTE--Laboratory of Soil Science, Station no. 2, CH-1015 Lausanne, Switzerland. keller@cerege.fr

Abstract

Phytoextraction is an environmentally sound method for cleaning up sites that are contaminated with toxic heavy metals. However, the method has been questioned because it produces a biomass-rich secondary waste containing the extracted metals. Therefore, further treatment of this biomass is necessary. In this study, we investigated whether thermal treatment could be a feasible option for evaporatively separating metals from the plant residues. We used a laboratory scale reactor designed to simulate the volatilization behavior of heavy metals in a grate furnace. The evaporation of alkali and heavy metals from plant samples was investigated online, using a thermo-desorption spectrometer (TDS). Experiments were performed in the temperature range of 25-950 degrees C with leaves of the Cd and Zn hyperaccumulator Thlaspi caerulescens and of the high biomass plant Salix viminalis (willow), both grown on contaminated soils. Gasification (i.e., pyrolysis), which occurs under reducing conditions, was a better method than incineration under oxidizing conditions to increase volatilization and, hence subsequently recovery, of Cd and Zn from plants. It would also allow the recycling of the bottom ash as fertilizer. Thus, our investigations confirmed that incineration (or co-incineration) is a viable option for the treatment of the heavy metal-enriched plants.

PMID:
15926590
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center