Study On The Treatment Of Ciprofloxacin Wastewater By Electrolysis-Ozone SBR Biodegradation

Antibiotics are widely used for curing human and veterinary diseases, as well as feed additives for livestock growth. However, exposure to one compound would lead to human body resistance against a whole class of antibiotics. Due to the potential adverse effects on aquatic ecology and human health, the present of antibiotics in aquatic environments received special concern, especially their potential for migration into the environment and the possible development of resistance in pathogens. Due to the antibacterial nature and its toxicity, most conventional treatments applied in WWTPs and DWTPs(such as physical methods andbiological water treatment methods) were unsuccessful in the removal of CIP, requiring the development of new efficient methodologies. Thus, the application of the advanced oxidation processes(AOPs) emerged as an alternative.In this study, a combined strategy of an electro-peroxone(E-peroxone) pretreatment followed by a Sequencing Batch Reactor(SBR) was evaluated for synthetic wastewater containing antibiotic of 200 mg·L-1 Ciprofloxacin(CIP). It was proved to be a successful strategy for the CIP treatment. The optimum operating conditions of E-peroxonewas p H: 9,current: 400 m A and ozone concentration: 5 g·h-1. Under optimum conditions, different treatment time CIP effluents were used as feed for SBR. When 75 min E-peroxone pretreatment combined with 12 h of biological treatment in the SBR allowed removing a 92.8 % of initial TOC, of which 58% by E-peroxone and 34.8% by biological treatment. HRT of 12 h was found suitable for the SBR and increasing HRT from 12 h did not significantly improve SBR efficiency in terms of COD and TOC removal.Meanwhile, Daphnia magna toxicity test methods was used, mainly based on large flea inhibition by the antibiotic wastewater to characterize bio-inhibitory changes of antibiotics wastewater before and after AOPs, and post-biological treatment. E-peroxneSBR system significantly reduced CIP wastewater bio-inhibitory, reduced from the initial of 20% to the final about 5%.In the last, we compared the impact of different pretreatment time of E-peroxone combined with SBR on ARG prevalence in activated sludge isolates, and to assess whether the E-peroxone-SBR process could control the dissemination of ARGs. The detection of RT-PCR illustrated the 75 min E-peroxone combined SBR can reduced the amount of the gene effectively in the sample. And this method showed potential in preventing the spread of resistance genes in aquatic environment. Despite that, the combined method was not a very common practice, the good performance of electroperoxone-SBR suggested the assessed combination was feasible and had great potential for enhancing CIP treatment.