Antibiotics removal from aquaculture effluents by ozonation: chemical and toxicity descriptors

•Ozonation investigated for the removal of antibiotics from aquaculture effluents.•Oxytetracycline, sulfamethoxazole and trimethoprim attacked by O3 directly.•Florfenicol removed by hydroxyl radicals (HO•) only.•Sulfadimethoxine degradation is significantly affected by the water matrix.•Toxicological evaluation did not show increase of water toxicity after ozonation.