The use of biochar (BC) has been suggested for remediation of contaminated soils. In a recent study published in Water, Air, & Soil Pollution we aimed to investigate the role of microorganisms in sorption of PAH to BC-amended soils. Fungi, especially the wood and litter-degrading fungi, have shown the ability for humification and to degrade recalcitrant molecules, and are thus suitable model organisms.
Haplic Arenosol with high organic matter content was chosen to
highlight the importance of soil organic matter (SOM) in PAH sorption,
possibly to form non-extractable residue. Basidiomycetous fungi Agrocybe praecox and Phanerochaete velutina
grown on pine bark were inoculated in organic matter (OM)-rich Haplic
Arenosol and OM-poor sandy loam with either BC or chemically activated
BC (ABC) and 14C-labelled pyrene for 60 days.
Fungi did not mineralize pyrene, but increased sorption up to 47–56%
in BC-amended Haplic Arenosol in comparison with controls (13–25%)
without a fungus irrespective of the presence of an adsorbent. In
OM-poor sandy loam, only 9–12% of pyrene was sorbed to amended soil in
the presence of fungus and adsorbent. The results suggest that BC and
fungal amendment increased sorption of pyrene, especially to Haplic
Arenosol more than by either BC or fungi alone.
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