Enhanced dissipation of polycyclic aromatic hydrocarbons in the presence of fresh plant residues and their extracts

The feasibility of using fresh plant residues and their extracts to stimulate the bio-dissipation of polycyclic aromatic hydrocarbons (PAHs) were highlighted. Wood chip, bamboo leave, orange peel and their water-extractable organic matter (WEOM) were chosen as amendment materials. Effect of WEOM on bio-dissipation (bioaccumulation and biodegradation) of phenanthrene and pyrene from water by two bacteria were investigated. Orange peel extract demonstrated the highest efficiency for stimulating PAHs removal by bacterium B1 (Pseudomonas putida), while bamboo leave extract was the best one to enhance PAHs bio-dissipation by bacterium B2 (unidentified bacterium isolated from PAHs-contaminated soil). Amended the actual contaminated soil with 1% plant residues, PAHs dissipation were increased by 15–20%, 20–39%, 14–24%, 12–23% and 17–26%, respectively, for 2-, 3-, 4-, 5- and 6-ring PAHs via stimulating indigenous microbial degradation activity. Bamboo leave exhibited the most effective one to stimulate dissipation of PAHs in contaminated soil.

Enhanced bio-dissipation of 15 PAHs in soil amended with fresh plant residues of wood chip (WC), orange peel (OP), and bamboo leave (BL). The individual symbol of AC, EC and BC is the abiotic sterile control, evaporation control and blank control.Figure optionsDownload as PowerPoint slideHighlights
► The addition of fresh plant extracts significantly enhance PAHs bio-dissipation from water.
► Bioaccumulation and biodegradation contribute to the bio-dissipation of PAHs in solution.
► The added fresh plant residues promotes 15 PAHs dissipation in PAHs-contaminated soil.
► Stimulating indigenous microbial degradation activity contributes to PAHs dissipation.
► Bamboo leave exhibits the most effective one to stimulate dissipation of PAHs in soil.