Aquaculture has developed strongly in recent decades, leading to highly sophisticated fish farms, making considerable use of feed, hormones and antibiotics, with a recognized environmental impact. To guarantee the economic sustainability of the sector, production has been intensified using water recirculation systems and appropriate treatments to optimize the use of this valuable resource. Concerns about the consequences of antibiotics’ use on public health have encouraged the development of strict regulations controlling its use and have led to a restricted number of antibiotics being licensed for aquaculture. In what concerns anaesthetics, only tricaine is approved by Food and Drug Administration. The World Health Organization warns for the misuse of antimicrobial medicines and points out that new resistance mechanisms are “making the latest generation of antibiotics virtually ineffective”. As far as we know, removal of fish pharmaceuticals from aquaculture effluents has not yet been studied. Photodegradation is an important mechanism in the degradation of compounds, containing aromatic rings or photoactive functional groups, as with most drugs. In aqueous environments, photosensitizers (which may be the drugs themselves or other species) absorb the light and transfer it to the dissolved oxygen or other substrate generating reactive oxygen species (ROS); in salt water, it might also promote the formation of reactive halogen species (RHS). These reactive species are responsible for the degradation of the target compounds. This project focuses on the development of a new green water treatment technology, aiming at the photodegradation of aquaculture pharmaceuticals under solar radiation, through the production of ROS formed under irradiation. Photocatalysts, such as nanomaterials obtained from carbon – carbon dots – will be synthesized and tested as synthetic photosensitizers, since they have been referred as a promising approach to increase photodegradation kinetic and thoroughly remove pharmaceuticals from wastewater, owing to its low budget and moderate reaction conditions. The knowledge of photodegradation products formed during the treatment process is essential, not only for academic reasons, but also for their biological properties. The identification of these main products through mass spectrometry techniques, as well as the evaluation of their antibacterial activity and toxicity will be goals to be achieved in this project. This project is rightly integrated in the Horizon 2020, the biggest EU Research and Innovation program ever, that includes the need to optimize and boost marine biotechnologies to fuel “blue” growth. The research team is multidisciplinary and will combine environmental chemistry, biology, mass spectrometry, and organic/inorganic chemistry. Also, the collaboration with aquaculture industry through SEA8 will allow to have a different vision towards our research and provide access to aquaculture effluents.