Sulfonated Pentablock Copolymer Coating of Polypropylene Filters for Dye and Metal Ions Effective Removal by Integrated Adsorption and Filtration Process.

In this work, we coated polypropylene (PP) fibrous filters with sulfonated pentablock copolymer (s-PBC) layers and tested them for the removal of cationic organic dyes, such as methylene blue (MB), and heavy metal ions (Fe3+ and Co2+) from water by adsorption and filtration experiments. Some of the coated filters were irradiated by UV light before being exposed to contaminated water and then were tested with unirradiated filters in the same adsorption and filtration experiments. Polymer-coated filters showed high efficiency in removing MB from an aqueous solution in both absorption and filtration processes, with 90% and 80% removal, respectively. On the other hand, for heavy metal ions (Fe3+ and Co2+), the coated filters showed a better removal performance in the filtration process than for the adsorption one. In fact, in the adsorption process, controlled interaction times allow the ionic species to interact with the surface of the filters leading to the formation and release of new species in solution. During filtration, the ionic species are easily trapped in the filters, in particular by UV modified filters, and we observed for Fe3+ ions a total removal (>99%) in a single filtration process and for Co2+ ions a larger removal with respect to the untreated filter. The mechanisms involved in the removal of the contaminants processes were investigated by characterizing the filters before and after use by means of scanning electron microscopy (SEM) combined with energy-dispersive X-ray (EDX) analysis and Fourier transform infrared spectroscopy (FT-IR).

Ag/ZnO/PMMA Nanocomposites for Efficient Water Reuse.

This work attempts to produce photocatalytic surfaces for large-scale applications by depositing nanostructured coatings on polymeric substrates. ZnO/poly(methyl methacrylate) (PMMA) composites were prepared by low-temperature atomic layer deposition (ALD) of ZnO on PMMA substrates. In addition, to increase the photocatalytic and antibacterial activities of ZnO films, Ag nanoparticles were added on ZnO surfaces using plasma-enhanced ALD. The morphology, crystallinity, and chemical composition of the specimens were meticulously examined by scanning and transmission electron microscopies, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. The noteworthy photocatalytic activity of the nanocomposites was proved by the degradation of the following organic pollutants in aqueous solution: methylene blue, paracetamol, and sodium lauryl sulfate. The antibacterial properties of the samples were tested using Escherichia coli as a model organism. Moreover, the possible toxic effects of the specimens were checked by biological tests. The present results unambiguously indicate the Ag/ZnO/PMMA nanocomposite as a powerful tool for an advanced wastewater treatment technology.