Effect of surfactant-coated iron oxide nanoparticles on the effluent water quality from a simulated sequencing batch reactor treating domestic wastewater

This study was conducted to evaluate the effect of commercially available engineered iron oxide nanoparticles coated with a surfactant (ENPFe-surf) on effluent water quality from a lab-scale sequencing batch reactor as a model secondary biological wastewater treatment. Results showed that ∼8.7% of ENPFe-surf applied were present in the effluent stream. The stable presence of ENPFe-surf was confirmed by analyzing the mean particle diameter and iron concentration in the effluent. Consequently, aqueous ENPFe-surf deteriorated the effluent water quality at a statistically significant level (p < 0.05) with respect to soluble chemical oxygen demand, turbidity, and apparent color. This implied that ENPFe-surf would be introduced into environmental receptors through the treated effluent and could potentially impact them.

► Surfactant-coated engineered iron oxide nanoparticles (ENPFe-surf) were assessed. ► Effluent quality was analyzed from a sequencing batch reactor with ENPFe-surf. ► ∼8.7% of ENPFe-surf applied was present in the effluent. ► ENPFe-surf significantly (p < 0.05) deteriorated the effluent water quality. ► Stable fraction of ENPFe-surf will be introduced into environmental receptors.