Abstract

Silver nanoparticles discharged from wastewater treatment plants pose potential risks to aquatic environments and, in the long term, may cause serious human health issues, hindering quality of life. Limited research has been conducted, making it difficult to ensure efficient removal of silver nanoparticles in wastewater treatment plants. This study evaluates the removal efficiency of silver nanoparticles across three wastewater treatment plant layouts: conventional activated sludge, an anoxic/oxic process configuration, and a 4-stage Bardenpho process system. Silver nanoparticle removal efficiency was 82%, and nitrogen removal efficiency exceeded 95% under steady-state conditions; however, under dynamic conditions, significant efficiency reductions were observed in the Bardenpho and anoxic/oxic configurations. The results also showed variability in organic matter and nitrogen removal due to reduced internal recirculation flowrates. The findings highlight the need to optimise certain configurations to ensure balanced performance across all pollutants.