Integrating constructed wetlands with maize cobs biological trickling filter for antibiotic removal: An innovative waste-to-treatment approach

The pervasive discharge of residual antibiotics into aquatic environments poses a significant ecological risk. This study pioneered a novel waste to treatment approach integrating a maize cob biological trickling filter (MC-BTF) with bamboo biochar-amended vertical wetlands (IVCWs) for enhanced sulfamethoxazole (SMX) and tetracycline (TC) removal. The hybrid system demonstrated sequential treatment efficiency: MC-BTF pre-treatment significantly increased dissolved oxygen from 4.47 ± 1.20 mg/L to 6.20 ± 0.71 mg/L while achieving 23.93 ± 6.21 % (SMX) and 23.64 ± 7.07 % (TC) antibiotic removal. Subsequent treatment in IVCWs revealed the bamboo biochar substrate (CW-E) outperformed no biochar amended wetlands, exceeding 90 % of both antibiotics. Concurrently, optimized nitrogen and phosphorus removal was attained, with microbial analysis confirming enriched nitrifiers and denitrifiers consortia, particularly Actinobacteria and Proteobacteria, responsible for SMX and TC biodegradation. This synergy of agriculture waste valorization (maize cobs and bamboo biochar) and integrated of IVCWs with MC-BTF established a cost-effective paradigm for simultaneous antibiotic and nutrient removal, advancing sustainable wastewater remediation.