In-sewer stability of illicit drug biomarkers has been evaluated by several reactorbased studies but less has been done in sewer pipes. Experiments conducted in sewer pipes have advantages over lab-scale reactors in providing more realistic biomarker stability due to the flow and biological dynamics. This study assessed the transportation and transformation of seven illicit drug biomarker compounds in a pilot-scale rising main and a gravity sewer pipe. Biomarkers presented diverse stability patterns in the pilot sewers, based on which a drug transformation model was calibrated. This model was subsequently validated using transformation datasets from literature, aiming to demonstrate the predictability of the pilot-based transformation coefficients under varying sewer conditions. Furthermore, transformation coefficients for five investigated biomarkers were generated from four studies and their prediction capabilities under the pilot sewer conditions were jointly assessed using performance statistics. The transformation model was successful in simulating the in-sewer stability for most illicit drugs. However, further study is required to delineate the sources and pathways for those compounds with potential formations to be simulated in the transformation model. Overall, the transformation model calibrated using the pilotsewer data is a credible tool for the application of wastewater-based epidemiology.
Although the occurrence, fate and behaviour of micropollutants in the urban water cycle is reported extensively in literature, the biotransformation of micropollutants in the sewer network has only received little attention. Rising main (RM) and gravity main sewer biofilms (GS) are capable of transforming sulfur species and organic compounds biochemically. Moreover, first laboratory-based and full-scale studies demonstrated the capability of sewer biofilms to transform illicit drugs, human drug metabolites and other human biomarkers, such as caffeine. However, the in-sewer biotransformation of pharmaceutically active compounds
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.