A framework for assessing the environmental safety of wastewater treated by advanced oxidation processes based on...

The occurrence of micropollutants in municipal wastewater effluents poses risks to ecosystems and human health, reinforcing the need for advanced treatment and comprehensive safety assessment. This study evaluates advanced oxidation processes (AOPs) for the removal of diclofenac (DCF) and sulfamethoxazole (SMX) and introduces a species sensitivity distribution (SSD)-based framework to assess effluent safety for aquatic and terrestrial organisms. Effluents from low- and middle-income country systems (UASB and UASB + trickling filter) and high-income country systems (conventional activated sludge, CAS, and nanofiltration, NF) were treated using Fenton- and UV-based AOPs. AOPs achieved >80% removal for both micropollutants in CAS and NF effluents but only ~44% in UASB effluents. Acute SSDs indicated post-AOP concentrations below hazardous levels for 95% of aquatic species (HC₅ = 250-284 μg L^-1), while chronic thresholds (HC₅ = 0.01-0.04 μg L^-1) were still exceeded, even after dilution. For agricultural reuse, terrestrial SSDs showed no phytotoxic risks. While AOPs reduced acute ecotoxicity, optimization remains essential to address chronic toxicity and ensure sustainable wastewater reuse and discharge, even when meeting the 80% micropollutants removal target (EU Directive 2024/3019). The proposed framework applies the One Health approach to evaluate treated municipal wastewater safety through SSD approach considering chronic toxicity risks, supporting the selection of appropriate aquatic and terrestrial test-organisms, and regulatory compliance.