Persulfate activation by Cr2O3/BC derived from chrome shavings for antibiotics degradation

Carbonaceous materials have attracted considerable attention as promising catalysts of persulfate (PS) activation for antibiotic degradation. In this work, an environment-friendly and low-cost carbonaceous material (Cr2O3/BC) was prepared by pyrolyzing chrome shavings, and the catalytic ability of Cr2O3/BC for PS activation was evaluated using tetracycline (TC) as the model antibiotic. The Cr2O3/BC/PS system exhibited ultrafast TC removal efficiency (99.9% removal rate within 5 min), which was owing to persistent free radicals, defective sites, and dispersed Cr2O3 particles, which were beneficial for the generation of free radicals, such as OH·, SO4·-, ·O2– and 1O2. Coexisting substances, such as inorganic ions and humic acid, exerted little effect on TC removal. In addition, 99.9% of TC removal rates were achieved in TC contaminated tap water. Cr2O3/BC/PS system also exhibited the high removal rates towards ciprofloxacin (98% removal rate within 5 min) and sulfadiazine (99.8% removal rate within 5 min). Surprisingly, no chromium was detected after TC degradation, indicating that no secondary pollution was generated. This work provides a feasible strategy for the high-value use of chrome shavings and a practical method for antibiotic removal.