Construction of Mass Balances of Cocaine in Batch Studies for the Sewage Treatment Works

Abstract

The desired approach at safeguarding the environment both in control and effective monitoring of chemical discharges is the use of mass balances to account for inflow/outflow of pollutants. Whereas the previous studies were based on several assumptions, the batch studies enabled the construction of mass balances for the Sewage Treatment Work (STWs) using the removal rate data. This study, for the first time measures the rates of removal of cocaine in an STW, and the calculated mass balances were obtained from the removal rate data that were generated. The result of cocaine initial influent of 50 mg L^-1 after after 2 hour hydraulic retention times (HRT) produced the final effluents of 110 mg L^-1. Projected influent concentrations of cocaine (14, 471 ng L^-1) were derived from back-calculation from final effluent concentrations. A useful tool that accounts for the mass-flow of trace drugs in the aquatic environment with minimal errors often due to sampling logistics and desludging process has been provided in this model of mass balance calculations in STWs.

Keywords: removal rate, effluent, influent, mass balance, sewage treatment work, cocaine