ALL libraries (COBIB.SI union bibliographic/catalogue database)
13.
Bioremediation of waste copper/chromium treated wood using wood decay fungi
Humar, Miha ; Pohleven, Franc ; Amartey, Sam A.
The expected service life of copper/chromium (CCA or CCB) treated wood is about 20 - 50 years. After that period, the treated wood is discarded as waste. Due to the toxic elements in such treated ...wood, burning and landfill disposal are not considered as environmentally friendly solutions. Extraction and recycling of the preservatives from the waste wood is a much more promising and environmentally friendly solution, which is based on the conversion of the fixed biocides in the wood into soluble forms which can subsequently be leached out of the wood. In order to elucidate the mechanism of this process, copper/chromium treated wood samples were leached after exposure to copper tolerant (Antrodia vaillantii and Leucogyrophana pinastri) and copper sensitive wood decay fungi (Gloeophyllum trabeum and Poria monticola). Furthermore, the ability of fungal hyphae to penetrate and overgrow the wood samples was investigated using following methods. Small stick of unimpregnated wood (r = 1.5 mm, l = 25 mm) was inserted into a hole, bored in the center of the samples, and after that sealed with epoxy sealer. Sterilized, leached and non-leached impregnated and unimpregnated specimens were exposed to brown rot fungi for one, two, five, eight or twelve weeks. After respective period, the inserted wood pieces were removed from the specimens and put onto nutrient medium containing petri dish. Possible growth of the hyphae from those pieces was than visually determined. Rate of colonization was determined by measurement of CO2 production as well. The fungal growths were stimulated by immersing of the specimens into aqueous solution of glucose or corn step liquor prior to exposure to fungi. Followed exposure the fungi, specimens were leached and concentrations of copper and chromium leached were determined. Afterwards, EPR measurements of leached and non-leached samples were performed in order to determine the paramagnetic complexes that were formed. The fastest colonization of impregnated wood was found at copper tolerant A. vaillantii. Addition of nutrients onto the surface of the specimens increased the colonization of the specimens. All wood decay fungi investigated as copper tolerant as well as copper sensitive increased heavy metals leaching from the treated wood. These fungi influenced the de-fixation process via oxalates formation. EPR measurements indicates that the transformation of copper into copper oxalate by the fungi was found to be essential but not the only mechanism responsible for copper tolerance by these fungi. However, from our results, it seems that other acids were also responsible for increased copper and/or chromium leaching. These results are important in elucidating copper toxicity by wood decay fungi and at using of these fungi for bioremediation of treated wood wastes.
It was not necessary to add the material to the shelf.
Bibliographic material was successfully added on shelf.
Adding bibliographical material on shelf was not successful.
Material is already on the shelf.
Permalink
URL:
Impact factor
Access to the JCR database is permitted only to users from Slovenia. Your current IP address is not on the list of IP addresses with access permission, and authentication with the relevant AAI accout is required.
Year
Impact factor
Edition
Category
Classification
JCR
SNIP
JCR
SNIP
JCR
SNIP
JCR
SNIP
Select the library membership card:
DRS,
in which the journal is indexed
Database name
Field
Year
Links to authors' personal bibliographies
Links to information on researchers in the SICRIS system
Subject headings in COBISS General List of Subject Headings
Select pickup location
The material from the parent unit is free. If the material is delivered to the pickup location from another unit, the library may charge you for this service.
