Surfactant-aided mycoremediation of soil contaminated with polycyclic aromatic hydrocarbons

Remediation of persistent polycyclic aromatic hydrocarbons (PAHs) contaminated soil has become a major challenge in recent years. Further, conventional application of bioaugmentation strategies for PAHs remediation require continuous supply of microbial specific nutrients, which makes these processes less feasible. Hence, the present study focused on PAHs remediation using surfactants along with wood assisted fungal system in a microcosm set up. In this study, in absence of surfactants, a saturation in PAHs degradation was noted in bioaugmentation with wood assisted fungal system (BAW) with 61 & PLUSMN; 1.25% degradation, followed by bioaugmentation with free fungi system (BAF) (54 & PLUSMN; 0.46%). However, with addition of 1500 mg/L of surfaceactive compounds (SAC), a maximum PAHs degradation in BAW (100%) and BAF (86 & PLUSMN; 1.30%) strategies were noted on 21st day. Irrespective of the strategies, presence of SAC and rhamnolipids enhanced PAHs degradation by increasing the enzymes production in Trametes hirsuta when compared to Triton x-100 and sodium dodecyl sulphate (SDS). Among the detected PAHs, 100% degradation within 17 days was noted for naphthalene and acenaphthene in SAC-supplemented BAW system. Further, ecotoxicity analysis established showed the LC50 of sediment soil at 26.5 & PLUSMN; 0.24%, which was reduced by an average of 71% after soil remediation. Hence, the current microcosm system proved that the application of SAC with BAW enhanced the PAHs remediation rate, which supports its application in real time soil remediation.

Automated summary

Remediation of persistent polycyclic aromatic hydrocarbons (PAHs) contaminated soil has become a major challenge in recent years. The application of surfactants along with wood assisted fungal system can enhance the PAHs remediation rate, and the addition of surface-active compounds can significantly increase enzyme production for degradation.