Enhanced Biodegradation of High-Concentration Di(2-ethylhexyl) phthalate by a Biochar-Immobilized Microbial Consortium

Di(2-ethylhexyl) phthalate (DEHP) is a widespread plasticizer and environmental contaminant. In this study, a highly efficient DEHP-degrading consortium, LCF, was enriched using DEHP as the sole carbon source. LCF achieved >92% DEHP removal within 48 h over a wide concentration range of 50–2000 mg/L, and the degradation followed first-order kinetics with half-lives of 7.63 –12.70 h. LCF maintained high activity under diverse environmental conditions (25–40°C, pH 7–10) and degraded multiple phthalate esters and key intermediates. Further, the corn straw biochar-immobilized microbial agent CSC-LCF improved DEHP removal in simulated wastewater by 33% over the free consortium, likely through coupled adsorption, sustained release, and biodegradation. Community analysis showed that LCF was dominated by Gordonia , Variovorax , and Rhodococcus . Combined with functional prediction and intermediate degradation results, a putative degradation pathway involving ester hydrolysis, aromatic intermediate transformation, and ring-cleavage metabolism was proposed. This study provides a valuable microbial resource and application reference for the bioremediation of phthalate-contaminated environments.