Study on tetracycline degradation in wastewater based on zero-valent nano iron assisted micro-nano bubbles

The presence of antibiotics in wastewater has become a significant concern due to their potential environmental impact and contribution to antibiotic resistance. In this study, we investigated the degradation of tetracycline, a commonly used antibiotic, in wastewater using a system based on zero-valent nano iron assisted micro-nano bubbles (MB/nZVI). The synthesized nZVI-BC composite, consisting of nano zero-valent iron particles loaded onto phosphoric acid-activated biochar, served as an efficient adsorbent for tetracycline removal. Our findings revealed that the combination of MBs and nZVI significantly enhanced the degradation efficiency of tetracycline. The MB/nZVI system exhibited the highest removal rate of 82.81% after a 2 h reaction, surpassing the perfor-mance of MB alone, nZVI-BC alone, and conventional bubble (CB)/nZVI-BC systems. Furthermore, the MB/nZVI system showed superior degradation performance at a dosage of 25 g/L and an MB flow rate of 30 mL/min. The pH condition had no significant effect on tetracycline degradation in the MB/nZVI system. Our results demon-strate that the use of MB/nZVI has the potential to be a sustainable and efficient approach for the remediation of tetracycline-contaminated wastewater.