Antibiotics 1 Azithromycin 1 Ebro River 1 Ebro River basin 1 Ebro river basin 1 Effluent treatment 1 Effluents 1 Emission sources 1 Hazardous substances 1 Hospital effluent 1 Hospitals 1 Long term study 1 Quantitative monitoring 1 Rivers 1 Sewage pumping plants 1 Slaughterhouse effluents Spain 1 Trimethoprim 1 Wastewater treatment 1 Water monitoring 1 Water treatment plants 1 Watersheds 1 antibiotics 1 concentration (composition) 1 effluent 1 farming system 1 hospital effluent 1 intensive agriculture 1 slaughterhouse effluent 1 wastewater treatment 1