Antibiotics are widely used in human and veterinary medication and have been frequently detected in the municipal sewage and the wastewater from the livestock industry and aquaculture. However, the current wastewater treatment facilities cannot effectively eliminate the antibiotics which consequently may occur in natural water bodies and even in tap water. Some of them may transform in the natural and engineered facilities into new substances called transformation products (TPs), which might even be more problematic than their original forms. In addition, the wide occurrence of antibiotics may lead to the development of antibiotic resistance genes (ARGs) among the exposed microorganisms. ARGs can further spread to other microorganisms which are not in direct contact with the antibiotics. With the involvement of new ecotoxicological methods like proteomics and metabolomics, more subtle impacts of antibiotics, TPs, and ARGs can be revealed. Therefore, it is of great interest to develop effective control technologies for both antibiotics and ARGs. Catalytic oxidation can generate strong oxidative species, e.g. hydroxyl radicals, which are often initiated by catalytic materials or external energy input like photon or ultrasound, which can effectively crack down the antibiotics and inactivate the antibiotics resistance bacteria and their ARGs. The adsorption process is also frequently studied owing to its operation ease which may use a natural product as a cheap adsorbent or a finely designed material with an extremely high adsorption capacity or a strong selectivity towards the target compounds. Nevertheless, attention should also be paid to the handling of the adsorbents loaded with contaminants. This Research Topic aims to report the cutting-edge results of quality studies on the occurrences and impact evaluation of antibiotics, TPs, and ARGs. This Research Topic welcomes high-quality Original Research and Review articles with the topics about the emerging contaminants in water, including but are not limited to the following areas: 1. Occurrence of antibiotics, TPs, and ARGs in wastewater and natural water bodies 2. Transformation of antibiotics in natural and engineered facilities 3. Transferring of ARGs between microorganisms 4. Ecotoxicological evaluation of antibiotics, TPs, and ARGs 5. Catalytic oxidation technologies 6. New adsorbents and handling of loaded adsorbents @en

UV/chlorine, as an emerging advanced oxidation process, is able to degrade organic micropollutants in water via the generation of reactive oxidant species and direct reaction with HOCl/OCl- as well. In this study, light-emitting diodes (LEDs) were applied as the UV sources to investigate the efficacy of UV/chlorine process for the degradation of trimethoprim (TMP, a frequently detected antibiotic in waters), at slightly alkaline pH.