title: Occurrence and fate of dissolved and particulate antimicrobials in municipal wastewater treatment.
abstract: Comprehensive study on the occurrence and fate of several classes of antimicrobials, including sulfonamides, trimethoprim, fluoroquinolones and macrolides, in Croatian municipal wastewaters was performed using an integrated approach, which comprised analysis of both dissolved and particulate fractions. A nation-wide screening showed ubiquitous occurrence of human-use antimicrobials in raw wastewater samples with the total concentrations ranging from 2 to 20 μg/L, while veterinary antimicrobials were typically present in much lower concentrations (<100 ng/L). The percentage of the particulate fraction in raw wastewater varied significantly depending on the type of the antimicrobial and the load of suspended solids. A detailed study of the mass flows of dissolved and particulate antimicrobials, performed in the wastewater treatment plant of the city of Zagreb, allowed an improved assessment of the biological and physico-chemical removal mechanisms of investigated compounds during the conventional activated sludge treatment. The overall removal efficiencies of antimicrobials from the water phase were rather variable, ranging from 0% for trimethoprim to 85% for norfloxacin. A significant percentage of fluoroquinolones (norfloxacin and ciprofloxacin) and macrolides (azithromycin and clarithromycin) was associated with the primary and excess secondary sludge, explaining 14-77% of the total removal. The removal, which could be attributed to biological transformation, was relatively poor for all antimicrobials, exceeding 30% only for SMX (32%) and clarithromycin (55%).
authors.affiliation: Rudjer Boskovic Institute, Division for Marine and Environmental Research, Bijenicka cesta 54, 10000 Zagreb, Croatia.
authors.forename: Ivan
authors.initials: I
authors.lastname: Senta
authors.forename: Senka
authors.initials: S
authors.lastname: Terzic
authors.forename: Marijan
authors.initials: M
authors.lastname: Ahel
mesh_terms: D000327:Adsorption; D000818:Animals; D000890:Anti-Infective Agents / Q000032:analysis* / Q000737:chemistry; D055598:Chemical Phenomena; D002947:Cities; D017523:Croatia; D024841:Fluoroquinolones / Q000032:analysis / Q000737:chemistry; D006801:Humans; D009111:Local Government; D018942:Macrolides / Q000032:analysis / Q000737:chemistry; D012621:Seasons; D062611:Solid Waste / Q000032:analysis; D012995:Solubility; D013449:Sulfonamides / Q000032:analysis / Q000737:chemistry; D014295:Trimethoprim / Q000032:analysis / Q000737:chemistry; D019155:Veterinary Drugs / Q000032:analysis / Q000737:chemistry; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification; D014881:Water Supply / Q000032:analysis*
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D018942:Macrolides; D062611:Solid Waste; D013449:Sulfonamides; D014295:Trimethoprim; D019155:Veterinary Drugs; D062065:Wastewater; D014874:Water Pollutants, Chemical