In-stream attenuation of neuro-active pharmaceuticals and their metabolites

Environmental Science & Technology
By: , and 



In-stream attenuation was determined for 14 neuro-active pharmaceuticals and associated metabolites. Lagrangian sampling, which follows a parcel of water as it moves downstream, was used to link hydrological and chemical transformation processes. Wastewater loading of neuro-active compounds varied considerably over a span of several hours, and thus a sampling regime was used to verify that the Lagrangian parcel was being sampled and a mechanism was developed to correct measured concentrations if it was not. In-stream attenuation over the 5.4-km evaluated reach could be modeled as pseudo-first-order decay for 11 of the 14 evaluated neuro-active pharmaceutical compounds, illustrating the capacity of streams to reduce conveyance of neuro-active compounds downstream. Fluoxetine and N-desmethyl citalopram were the most rapidly attenuated compounds (t1/2 = 3.6 ± 0.3 h, 4.0 ± 0.2 h, respectively). Lamotrigine, 10,11,-dihydro-10,11,-dihydroxy-carbamazepine, and carbamazepine were the most persistent (t1/2 = 12 ± 2.0 h, 12 ± 2.6 h, 21 ± 4.5 h, respectively). Parent compounds (e.g., buproprion, carbamazepine, lamotrigine) generally were more persistent relative to their metabolites. Several compounds (citalopram, venlafaxine, O-desmethyl-venlafaxine) were not attenuated. It was postulated that the primary mechanism of removal for these compounds was interaction with bed sediments and stream biofilms, based on measured concentrations in stream biofilms and a column experiment using stream sediments.

Publication type Article
Publication Subtype Journal Article
Title In-stream attenuation of neuro-active pharmaceuticals and their metabolites
Series title Environmental Science & Technology
DOI 10.1021/es402158t
Volume 47
Issue 17
Year Published 2013
Language English
Publisher American Chemical Society
Publisher location Easton, PA
Contributing office(s) National Research Program - Central Branch
Description 10 p.
First page 9781
Last page 9790
Online Only (Y/N) N
Additional Online Files (Y/N) N
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