Simultaneous removal of organic micropollutants and metals from water by a multifunctional β-cyclodextrin polymer-supported-polyaniline composite

The occurrence of diverse pollutants in water resources across the globe, including organic micropollutants and heavy metals, has challenged the efficacy of many existing water treatment processes. Various materials and media have been developed for removal of these compounds, but few have the capacity to remove multiple contaminants which are typically present in real water sources. Here we report on a novel sorbent (PANI@PCDP) for the simultaneous removal of organic micropollutants and heavy metals during a single process. Cr(VI) and bisphenol A (BPA) were selected as target pollutants due to their frequent occurrence in aquatic environments and the significant health risks they pose. PANI@PCDP exhibited a high level of performance for removal of BPA and total Cr at pH 6 for initial concentrations of 0.5–100 mg/L for Cr(VI) and 0.228–22.8 mg/L for BPA. Up to 98 % Cr was removed at pH 6 through the adsorption and reduction of Cr(VI), followed by the sequestration of the generated Cr(III). In addition, BPA could be captured by PANI@PCDP at an adsorption rate of 1.4 × 10-1 g mg−1 min−1 as a result of the fast formation of complexes with the media. When the PANI@PCDP media was tested on a wider variety of emerging organic micropollutants (including chlorinated aromatic compounds, simple aromatics, and pharmaceuticals) good removal was observed. Such performance benefits arise from the integration of porous β-cyclodextrin polymers with polyaniline, which provides the PANI@PCDP with multiple binding sites for contaminant removal. In addition, the PANI@PCDP can be regenerated at least five times without loss in performance using a facile procedure, providing evidence for its practical application in water treatment.