Assessing the performance of an integrated column system containing zero valent iron nanoparticles and sodium persulfate solution for the removal of emerging contaminants from different wastewater matrices – Identification of transformation products

Abstract

The occurrence of micropollutants in the aquatic environment has raised the scientific concern because of their continuous discharge, their bioaccumulation and their potential adverse toxicological impacts on both aquatic organisms and human health. The present study has been focused in the assessment of the performance of an integrated column system in terms of the removal efficiency of selected micropollutants as a post-treatment step for different effluent matrices: an anaerobic membrane bioreactor (AnMBR), an upflow anaerobic sludge blanket reactor (UASB) followed by microfiltration, a sand filter after treatment of a septic tank followed by a saturated vertical wetland and a conventional tertiary treatment system. The system consists of a nanocomposite material, which is called R-nFe and includes zero-valent iron nanoparticles (nZVI) hosted into a strongly acidic cation exchange resin, and a sodium persulfate solution (PS) at a concentration of 1 mM, while the influent pH is acidic and the contact time 2.2 min. In addition, the transformation products of diclofenac and bisphenol A are being investigated. To the authors’ best knowledge, this is the first time that the synergistic action of nZVI with PS is evaluated for the removal of micropollutants under continuous real wastewater flow with different matrix characteristics.