Occurrence of illicit drugs in two wastewater treatment plants in the South of Italy

In this study the occurrence and the behavior of illicit drugs and their metabolites have been investigated for two wastewater treatment plants (WWTPs) (namely, WWTP-1 and WWTP-2) located in Sicily (island of Italy). Samples were analyzed for methamphetamine, cocaine (COC), 3,4-methylenedioxymethamphetamine (MDMA), methadone (METH), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), 3,4-methylenedioxy amphetamine (MDA); 3,4-methylenedioxy ethylamphetamine (MDEA), 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) and Benzoylecgonine (BEG). The BEG, COC, MOR and THC-COOH were found at the highest concentration in both WWTPs. The Wastewater-based epidemiology calculation for BEG, COC, cannabinoids and THC-COOH was performed. On average, for both plants, population consumes 1.6 and 23.4 dose 1000 inh−1 day−1 of cocaine and cannabis, respectively. For WWTP-1 negative removals of illicit drugs were observed. For WWTP-2 the following average removal efficiencies were obtained: BEG (77.85%), COC (92.34%), CODEINE (64.75%), MOR (90.16%) and THC-COOH (68.64%). [Display omitted] •Two wastewater treatment plants have been monitored in terms of illicit drugs.•Cocaine and cannabis metabolites have been found in both plants.•High average removal efficiency were found for MOR (90.16%) in WWTP-1.•Population consume 1.6 doses per 1000 inh−1 day−1 of cocaine.•Population consume 23.4 doses per 1000 inh−1 day−1 of cannabis.