Influence of black carbon addition on phenanthrene dissipation and microbial community structure in soil

Biodegradation processes and changes in microbial community structure were investigated in black carbon (BC) amended soils in a laboratory experiment using two soils (black soil and red soil). We applied different percentages of charcoal as BC (0%, 0.5% and 1% by weight) with 100 mg kg−1 of phenanthrene. Soil samples were collected at different incubation times (0, 7, 15, 30, 60, 120 d). The amendment with BC caused a marked decrease in the dissipation (ascribed to mainly degradation and/or sequestration) of phenanthrene residues from soil. Extracted phenanthrene in black soil with 1% BC were higher, oppositely in red soil, 0.5% BC amendments were higher. There were significant changes in the PLFA pattern in phenanthrene-spiked soils with time but BC had little effect on the microbial community structure of phenanthrene-spiked soils, as indicated by principal component analysis (PCA) of the PLFA signatures.

► Extracted phenanthrene increased substantially as the BC amount increased.
► Extracted phenanthrene in black soil with 1% BC were higher, oppositely in red soil.
► BC caused a marked decrease in the dissipation of phenanthrene from soil.
► PLFA pattern in phenanthrene-spiked soils with time had significant changes.