Persistent polycyclic aromatic hydrocarbons removal from sewage sludge-amended soil through phytoremediation combined with solid-state ligninolytic fungal cultures.

Polycyclic aromatic hydrocarbons (PAHs) are widely present in the environment, causing increasing concern because of their impact on soil health, food safety and potential health risks. Four bioremediation strategies were examined to assess the dissipation of PAHs in agricultural soil amended with sewage sludge over a period of 120 days: soil-sludge natural attenuation (SS); phytoremediation using maize (Zea mays L.) (PSS); mycoremediation (MR) separately using three white-rot fungi (Pleurotus ostreatus, Phanerochaete chrysosporium and Irpex lacteus); and plant-assisted mycoremediation (PMR) using a combination of maize and fungi. In the time frame of the experiment, mycoremediation using P. chrysosporium (MR-PH) exhibited a significantly higher (P < 0.05) degradation of total PAHs compared to the SS and PSS treatments, achieving a degradation rate of 52 %. Both the SS and PSS treatments demonstrated a lower degradation rate of total PAHs, with removal rates of 18 % and 32 %, respectively. The PMR treatments showed the highest removal rates of total PAHs at the end of the study, with degradation rates of 48-60 %. In the shoots of maize, only low- and medium-molecular-weight PAHs were found in both the PSS and PMR treatments. The calculated translocation and bioconversion factors always showed values < 1. The analysed enzymatic activities were higher in the PMR treatments compared to other treatments, which can be positively related to the higher degradation of PAHs in the soil.

Bioremediation of the synthetic musk compounds Galaxolide and Tonalide by white rot fungal strain-assisted phytoremediation in biosolid-amended soil.

The study was aimed to conduct the bioremediation of synthetic musks by four species of white rot fungi combined with phytoremediation (Zea mays) in biosolid-amended soils where only Galaxolide (HHCB) and Tonalide (AHTN) were found as other musks were below the detection limit (0.5-2 µg/kg dw). The HHCB and AHTN concentration in natural attenuation treated soil was decreased by not more than 9%. In solely mycoremediation, Pleurotus ostreatus was found to be the most efficient fungal strain, with the higher (P < 0.05) HHCB and AHTN removal (51.3% and 46.4%). Phytoremediation-only of biosolid-amended soil was also able to remove HHCB and AHTN from soil significantly (P < 0.05) in comparison to the control treatment without plants which resulted in the final concentration for both compounds of 56.2 and 15.3 µg/kg dw, respectively. Using white rot fungus-assisted phytoremediation, only P. ostreatus decreased the HHCB content in soil significantly (P < 0.05) by 44.7%, when compared to the initial concentration. While using Phanerochaete chrysosporium, the AHTN concentration was decreased by 34.5%, which was a significantly lower concentration at the end of experiment compared to the initial value. Via fungus-assisted phytoremediation, the enzymatic activity and fungal biomass were increased, probably due to the presence of roots in association with the soil microbiome, in the process increasing the degradation of fragrances accordingly. This could lead to a higher (P < 0.05) AHTN removal in P. chrysosporium assisted phytoremediation. Estimated HHCB and AHTN bioaccumulation factors in maize were lower than 1, therefore no environmental risk would be posed.