固定化菌剂驱动下PAHs污染农田土壤固碳消污的效应及机制OA

To address the dual challenges of soil polycyclic aromatic hydrocarbons(PAHs)contamination and climate change,this study developed a biochar-immobilized microbial agent(BIM)with carbon sequestration and PAH removal capabilities.Pot experiments were conducted to investigate the optimal application strategy for BIM and elucidate its underlying mechanisms.Results indicated that BIM at a 1%dosage(BIM1%)demonstrated optimal carbon sequestration and PAHs removal efficacy,enhancing soil PAHs removal rates by 138.70%±16.42%and reducing PAH accumulation in lettuce by 76.86%±2.49%.Concurrently,cumulative CO2 emissions were significantly reduced,while total carbon(TC)and soil organic carbon(SOC)content increased significantly(P<0.05).Based on the Random Forest(RF)model,we found that BIM's contribution to carbon sequestration and PAHs removal primarily depended on changes in microbial properties.BIM1%treatment significantly increased the abundance of carbon-fixing microorganisms and PAH-degrading microorganisms in soil,along with the activity of carbon sequestration-associated enzymes,representing key influencing factors.The robustness of co-occurrence networks and cooperation among microbial species also exerted positive effects on PAHs removal and carbon sequestration.Furthermore,the significant enrichment of carbon-fixing microorganisms(ASV_64 and ASV_145)and PAH-degrading microorganisms(ASV_264 and ASV_2943)in the BIM1%treatment enhanced both carbon sequestration and PAH removal efficiency.The BIM prepared in this study holds promise for simultaneously achieving PAH removal and CO2 sequestration,offering a potential solution for ensuring agricultural production safety and mitigating climate change.