Structured organic frameworks as endocrine disruptor adsorbents suitable for Fenton regeneration and reuse

Abstract

New porous materials, such as metal-organic frameworks (MOFs) and covalent-organic frameworks (COFs), have been actively investigated due to their environmental applications. In this study, four of such structured materials, namely Fe3O4 @COF, MIL-53(Al), MIL-53(Al)-F127 and NH2-MIL-101(Fe) were synthetized. These materials have been tested for the first time for the adsorption in aqueous media of two endocrine disruptor pollutants, bisphenol A (BPA) and prednisolone (PDN). The adsorbents were characterized by the analysis of the point of zero charge (PZC), the functional groups (FTIR) and their physic-chemical structure (N2-isotherms, SEM, XRD and XPS). MIL-53-Al provided the highest uptake of both BPA (177.78 mg g−1) and PDN (280.70 mg g−1) even when using a real wastewater matrix. Additionally, this MOF resulted to be a so-called catalytic-adsorbent, maintaining an appropriate adsorbent capacity after five regenerations cycles via Fenton-like process, causing only 20% and 5% adsorption detriment for BPA and PDN, respectively. This avoids spent adsorbent disposal issues and make this new kind of adsorbent to have the potential to be used in real environmental application scenarios.