Occurrence and in-stream attenuation of wastewater-derived pharmaceuticals in Iberian rivers

• Published in: The Science of the total environment Vol. 503-504; pp. 133 - 141
• Main Authors: Acuña, Vicenç, von Schiller, Daniel, García-Galán, Maria Jesús, Rodríguez-Mozaz, Sara, Corominas, Lluís, Petrovic, Mira, Poch, Manel, Barceló, Damià, Sabater, Sergi
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15-01-2015; Elsevier
• Subjects: Aigua; Aigües residuals; Aspectes ambientals; Biotransformation; Contaminació; Depuració; Drugs; Ecosystem services; Environmental aspects; Environmental Monitoring; Medicaments; Models, Chemical; Natural contaminant attenuation; Pharmaceutical Preparations - analysis; Pharmaceuticals; Photolysis; Pollution; Purification; Rivers - chemistry; Sewage; Spain; Stream ecology; Waste Water - analysis; Waste Water - chemistry; Waste Water - statistics & numerical data; Water; Water Pollutants, Chemical - analysis; Water purification; Water quality; Spain; Spain, Galicia; Stream ecology; Natural contaminant attenuation; Ecosystem services; Water purification; Water quality; Pharmaceuticals
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2014.05.067

A multitude of pharmaceuticals enter surface waters via discharges of wastewater treatment plants (WWTPs), and many raise environmental and health concerns. Chemical fate models predict their concentrations using estimates of mass loading, dilution and in-stream attenuation. However, current comprehension of the attenuation rates remains a limiting factor for predictive models. We assessed in-stream attenuation of 75 pharmaceuticals in 4 river segments, aiming to characterize in-stream attenuation variability among different pharmaceutical compounds, as well as among river segments differing in environmental conditions. Our study revealed that in-stream attenuation was highly variable among pharmaceuticals and river segments and that none of the considered pharmaceutical physicochemical and molecular properties proved to be relevant in determining the mean attenuation rates. Instead, the octanol–water partition coefficient (Kow) influenced the variability of rates among river segments, likely due to its effect on sorption to sediments and suspended particles, and therefore influencing the balance between the different attenuation mechanisms (biotransformation, photolysis, sorption, and volatilization). The magnitude of the measured attenuation rates urges scientists to consider them as important as dilution when aiming to predict concentrations in freshwater ecosystems.
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•In-stream attenuation was highly variable among pharmaceuticals and river segments.•Kow influenced attenuation through effect on sorption to sediments.•Likely coupling between pharmaceuticals and phosphorus attenuation.•In-stream attenuation as important as dilution to explain concentrations.