Enhanced biodegradation of High-Concentration Di(2-ethylhexyl) phthalate by a Biochar-Immobilized microbial...

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.