ZnO-based materials and enzymes hybrid systems as highly efficient catalysts for recalcitrant pollutants abatement

The presence of pollutants in water systems is a universal threat. In this study, ZnO based materials and enzyme hybrid materials were evaluated for their ability to remove six emerging wastewater pollutants (namely diclofenac, naproxen, iopamidol, imidacloprid, bisphenol A and 2,4-dichlorophenol). These materials were tested in their free form as well as supported on poly(styrene-co-maleic anhydride) (SMA) nanofibre mats fabricated through the process of electrospinning. The SMA nanofibres were fully characterized using Attenuated Total Reflectance-Fourier Transform InfraRed spectroscopy (ATR-FTIR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Degradation profiles of the activity of these and the Ce-doped ZnO materials in their free form showed good removal efficacy of all the contaminants even in a mixed matrix environment which mimics a real scenario. By combining Soybean peroxidase (SBP) attached to the SMA nanofibres and oxide nanoparticles into the polymer nanofibers, a synergic effect was observed and it was particularly marked for the Ce-doped ZnO in wastewater treatment. Supporting these materials on the SMA nanofibre mats did not compromise on the effectiveness of the materials. These supported materials offer a potentially easier and more practical application of the materials in water treatment applications.