Anthracene and benzo(a)pyrene degradation in soil is favoured by compost amendment: Perspectives for a bioremediation approach

In order to validate the use of compost in soil PAH bioremediation, the degradation of anthracene and benzo(a)pyrene was monitored in soils artificially contaminated and incubated in mesocosms under controlled conditions. The dynamics observed in compost amended soil were compared to those observed in soil added with a fungal consortium and untreated soil. At the same time, three microbial enzyme activities usually involved in PAH degradation (laccase, o-diphenol oxidase and peroxidase activities) were monitored. Both PAHs decreased along the time in the three mesocosms, with anthracene, with lower molecular weight, degrading with a higher rate and reaching lower residual values than benzo(a)pyrene. Although at the end of incubation, the residual values of investigated PAHs are similar in the three mesocosm types, PAH dynamics showed a higher degradation rate in the early stage in mesocosms added with the fungal mycelium and amended with compost. Among the three enzyme activities, only peroxidase showed higher values in treated than untreated mesocosms. Considering the ameliorating effects of compost on degraded soils, its use can be suggested in PAH bioremediation.