Improved remediation of amoxicillin-contaminated water by floating treatment wetlands intensified with biochar, nutrients, aeration, and antibiotic-degrading bacteria.

Residual antibiotics have become emerging contaminants of concern for their adverse impact on the ecosystem. Additionally, their accumulation in the environment is increasing antibiotic resistance among pathogens. This study assessed the impact of intensification of biochar, nutrients, aeration, and bacteria (BNAB) on the remediation potential of floating treatment wetlands (FTWs) to treat amoxicillin (AMX)-contaminated water. The FTWs were developed with saplings of and intensified with biochar (1.5%), nutrients (25 mgL N, 25 mgL P, 20 mg L K), aeration (7 mg L), and AMX-degrading bacteria. The results showed that all the amendments enhanced the AMX degradation, while the maximum reduction in COD (89%), BOD (88%), TOC (87%), and AMX (97%) was shown by the combined application of all the amendments. The combined application also enhanced plant growth and persistence of the inoculated bacteria in the water, roots, and shoots. This approach can be employed for the low-cost, environment-friendly treatment, and recycling of antibiotic-contaminated wastewater, where BNAB intensification can further improve the bioremediation efficiency of FTWs in the case of heavily polluted waters.