Monitoring ketamine use and evaluating its persistence across 106 wastewater treatment plants in Australia

Le résumé fourni par la source

Ketamine, commonly used for anaesthesia, has seen increasing recreational use worldwide. In this study, we aimed to (i) assess ketamine use across different regions in Australia, and (ii) evaluate ketamine removal during wastewater treatment processes and the associated ecological risks. Wastewater samples from 106 wastewater treatment plants (WWTPs) across Australia, covering 61% of the Australian population were collected and analysed for ketamine and its metabolite, norketamine. We found ketamine use was numerically higher in Major Cities (42 ± 82 mg/day/1000 people) compared to Inner Regional (32 ± 53 mg/day/1000 people) and Outer Regional to Very Remote areas (28 ± 44 mg/day/1000 people). The ketamine/norketamine ratio (4.9) remained stable from influent to effluent, suggesting that both compounds are removed at similar rates and that their relative abundance is largely stable during wastewater treatment. The mean removal efficiencies of ketamine and norketamine were 24% and 18%, respectively, demonstrating their persistence through conventional treatment processes. Removal performance was further compared across treatment configurations with different levels of complexity, including activated sludge, biofilter, chlorination, chemical phosphorus removal, and UV disinfection. These findings provide large-scale benchmarking data on the fate and removal of ketamine in wastewater treatment systems. Ecological risk assessment using effluent concentrations and predicted no-effect concentrations (PNEC) indicated negligible or low risk (risk quotient <0.1) to the aquatic environment.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.