Abstract
Polychlorinated biphenyls (PCBs) are anthropogenic compounds which belong to persistent organic pollutants. Because of their slow decomposition in nature they still remain an environmental burden despite their ban in the 1980s, and there is a need for a cost-effective and environmentally friendly approach to PCB removal from contaminated sites.
In bioremediation the group of white-rot fungi and especially Pleurotus ostreatus (the oyster mushroom), was found to have a high degradation potential towards PCBs and PCB metabolites, such as hydroxylated PCBs and chlorobenzoic acids. Moreover, the so-called spent substrate is produced world-wide as waste in commercial mushroom growing farms and can be used for bioremediation purposes.
In this work the degradation of PCBs by P. ostreatus from water matrix was studied. Firstly, the degradation was tested in flasks in batch setup with P. ostreatus inoculated on wheat straw pellets where it was able to remove about 20 µg of PCBs during 4 weeks of degradation.
On the basis of the results a laboratory scale tubular reactor filled with P. ostreatus spent substrate was designed. Continuous flow setup resulted in 97% removal of PCBs from artificially contaminated tap water (initial PCB concentration 50 µg.L-1; 10 L in total).
Finally, the reactor was scaled up (working volume 500 L) and used in trickle bed setup to clean up real contaminated water originated from a site of a former asphalt-concrete producing plant in the Czech Republic.