Ciprofloxacin (CIP) and CIP resistant bacteria are emerging concerns which threatening public health by higher antibiotic usage and resistance development of bacteria in the water environment. To tackle this problem, we used the UV-LED/chlorine process. CIP degradation followed pseudo-first order kinetics and excessive initial chlorine dosage have a negative effect on CIP removal. Alkaline pH was the best CIP removal compared to acidic and neutral pHs. Hydroxyl (OH) radicals mainly contributed to CIP degradation during the UV-LED/chlorine process at neutral pH while RCS (reactive chlorine species) played a major role at acidic and alkaline pHs. Eleven byproducts including two chlorinated byproducts and two anions (formate and nitrate) were detected using LC-QTOF-MS, GC-QTOF-MS, and ion chromatography. The cleavages of piperazine, cyclopropyl, and quinolone moiety cleavage were the major degradation reactions. The degradation pathways of CIP by the UV-LED/chlorine process was proposed using the identified byproducts. Micro toxicity text using V. fischeri showed that these byproducts induced the toxicity. UV-LED/chlorine process not only showed effective CIP removal, but also showed effective E. faecium disinfection. EE/O of UV-LED/chlorine was significantly low (6.63 × 10-2 kWh/m3/order). Our results indicate UV-LED/chlorine process is promising in terms of CIP and E. faecium removal.

Ciprofloxacin (CIP) degradation and CIP resistant E. faecium inactivation by UV-LED/Chlorine process

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.