Mass Balance Calculations of Illicit Drugs in Stoke Bardolph Sewage Treatment Works, United Kingdom

Abstract

 Work encompassed in this study directly measures illicit drug removal rates in laboratory studies. Researchers
employed removal rate data in calculating mass balances in sewage works which is an improvement over prior
studies where assumptions on removal rates at Sewage Treatment Works were made. The batch tests data
enabled determination of degradation of the compounds at different temperatures and times, using various
sludge types after characterization. Mass balances for the Stoke Bardolph Sewage Treatment Works were
constructed using the removal rate data from the batch studies. Final effluent concentrations of 10.0 ng L-1
(morphine), and 80.0 ng L-1 (6-monoacetylmorphine), were recorded after a total of 8 hour hydraulic times (8
HRT) from an initial influent concentration of 50 mg L-1. A projected influent concentration of morphine (1.4 g
L-1) at Stoke Bardolph was derived from back-calculating measured final effluent concentrations using the
same mass balance approach