Enhanced biodegradation of phenol using immobilized Pseudomonas alloputida BF04 in sequencing batch reactor

Abstract

Phenol, a prevalent and persistent organic contaminant in industrial effluents, is widely recognized for its susceptibility to biodegradation as an effective remediation strategy. In this study, the phenol-degrading bacterium Pseudomonas alloputida BF04 was isolated from petrochemical effluent and exhibited the capacity to degrade 500 mg/L of phenol within 30 h. Immobilizing strain BF04 in polyvinyl alcohol-sodium alginate (PVA-SA) beads markedly improved its tolerance to phenol and degradation efficiency. Batch reactor experiments employing immobilized beads achieved complete phenol removal under simulated wastewater conditions, sustaining a phenol degradation efficiency of 100%. Furthermore, the reactor exhibited significant removal efficiencies for Chemical Oxygen Demand (COD, 77%), Total Nitrogen (TN, 84%), and Ammonium (NH₄⁺, 82%) when the hydraulic retention time (HRT) was maintained above 24 h. Functional gene sequencing identified the dmp, Cat, and pca gene clusters in strain BF04, suggesting that phenol degradation occurs via the meta-cleavage pathway of aromatic ring opening. The results demonstrated that the immobilized Pseudomonas alloputida BF04 strain exhibited excellent degradation ability and stability, effectively addressing challenges in practical wastewater treatment. This study provides a valuable reference for advancing bioremediation technology.