Effect of carbon source on the degradation of 2-naphthalenesulfonic acid polymers mixture by Pleurotus ostreatus in petrochemical wastewater

The ability of the white rot fungus Pleurotus ostreatus to biodegrade 2-naphthalenesulfonic acid polymers(2-NSAP) contained in a petrochemical wastewater was evaluated. The characterization of the wastewaterand a LC–MS identification of polymers were performed. Biodegradation experiment was conducted inbatches with and without the addition of a carbon source (glucose, corn starch, cellulose and lignin). Ithas been demonstrated that, in presence of a suitable carbon source, P. ostreatus is able to remove NSAPranging from trimers to decamers. Interestingly, all the carbon sources utilized, despite the differentvelocities, allowed to degrade about 60–70% of the oligomers.Furthermore, respirometric tests showed that the fungal treatment was also able to significantlyincrease the bCOD/COD ratio, going from 9% (raw wastewater) up to 57%. This is clearly correlated withthe enhancement in oligomers depolymerization confirming that the fungal action is not a mineralizationof NSAP, but an increase of their biodegradability.