Microbially inoculated chars strongly reduce the mobility of alachlor and pentachlorobenzene in an alluvial sediment.

This study focused on the transport behavior and biodegradation of two organic contaminants, alachlor and pentachlorobenzene (PeCB), in Danube alluvial sediment amended with microbially inoculated carbon-based materials. Biochar produced at 400 °C and hydrochars produced at 180, 200, and 220 °C from Miscanthus × giganteus were inoculated with the bacterium Bacillus megaterium BD5, known for its biodegradation capabilities. Column experiments demonstrated that the addition of these inoculated chars significantly increased the retention (retardation factor) and biodegradation (biodegradation coefficient λ) of PeCB, particularly with hydrochar produced at 200 °C, while alachlor showed limited biodegradation. The findings suggest that inoculated carbon-based amendments could serve as a promising in situ remediation technique to reduce the mobility of persistent organic pollutants in sediments and prevent groundwater contamination, although further field studies are needed to confirm efficacy and safety.