Hybrid magnetic systems for the environmental remediation of wastewater

The continuous growing demand of fresh water to fulfil agricultural, industrial, and domestic needs of the global population points out the technological importance of performing smart and efficient wastewater remediation processes. One of the major problems related to water quality is represented by the impact due to emerging pollutants (EPs), a wide class of anthropic chemicals recently recognized (but poorly regulated), hardly removable by traditional treatments.[1] Hence, innovative heterogeneous processes based on the application of hybrid inorganic-organic magnet-responsive nanomaterials (MRNs, e.g., magnetic iron oxides) are receiving great attention as interesting alternative technologies exploitable in light-enhanced advanced oxidation processes (AOPs), and in more traditional sorption routes.[2] In this study, MRNs are functionalized by means of two different bio-based macromolecules, namely: BBS (i.e., humic-like substances isolated from green compost derived from agricultural biowaste), and chitosan (i.e., an amino-polysaccharide derived from shellfish industry biowaste). Both these organic macromolecules are in line with the “Waste Cleaning Waste” approach, very appealing from the green chemistry viewpoint.[3] Eventually, it has been investigated the possibility of converting such organic fractions into carbonaceous phases via pyrolysis, still maintaining the magnetic properties of the inorganic component. Hybrids MRNs are physicochemical, magnetic, and morphological characterized. Finally, in view of showing the potentiality of these hybrid systems, several case studies are discussed, in details: i) Testing BBS-iron oxide systems against caffeine (taken as model EPs) via light-enhanced AOPs at circumneutral conditions.[1] ii) Testing chitosan-derived carbonaceous-iron oxide systems against anthracene and naphthalene via sorption mechanism.[4] iii) Testing all hybrid systems against As(III) and As(V) via sorption mechanism.[5] Results indicate that these hybrid MRNs are a promising technological solution for the new generations of wastewater purification treatments. Acknowledgements: European Commission H2020-MSCA-RISE-2014, research project Mat4treaT (Project 645551). [1] F. Franzoso, R. Nisticò, F. Cesano, I. Corazzari, F. Turci, D. Scarano, A. Bianco Prevot, G. Magnacca, L. Carlos, D.O. Martire, Chemical Engineering Journal 2017, 310, 307-316. [2] R. Nisticò, Research on Chemical Intermediates 2017, 43, 6911-6949. [3] P. Avetta, F. Bella, A. Bianco Prevot, E. Laurenti, E. Montoneri, A. Arques, L. Carlos, ACS Sustainable Chemistry and Engineering 2013, 1, 1545-1550. [4] R. Nisticò, F. Franzoso, F. Cesano, D. Scarano, G. Magnacca, M.E. Parolo, L. Carlos, ACS Sustainable Chemistry and Engineering 2017, 5, 793-801. [5] R. Nisticò, L.R. Celi, A. Bianco Prevot, L. Carlos, G. Magnacca, E. Zanzo, M. Martin, Journal of Hazardous Materials 2018, 342, 260-269.