The case study presented in the paper is the first in the field to find microplastic (MP) particles in both grey water (GW) and post-treatment sewage (TS) samples, which can also be legally discharged into specially protected areas. Compiling a data set of 50 water samples collected from the GW and TS samples of 5 transport ships involved in the case study, we show that the mean number of separated microparticles in the GW samples n = 72 particles per litre, and in the TS samples n = 51 particles per litre. Of the 614 separated particles, the most common were fibres n = 285 (46.4%), followed by other (various) hard particles n = 226 (36.8%) and soft particles n = 104 (16.8%). Attenuated total reflectance Fourier transform infrared spectroscopy (ATR FT-IR) identification was mainly in the form polyethylene (PE), polypropylene (PP) (solid particles and films), polyesters, polyamides, and acrylic fibres. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis revealed ecotoxic chemical elements on the surface of these particles. Our results show that the sewage treatment facilities installed on ships need to be improved, and we developed a solution for this. The findings of the case study certainly deserve further attention and serve as an impetus for research on the improvement of ship wastewater treatment facilities.

Lightweight magnesium alloys offer excellent benefits over Al alloys due to their high specific strength and damping properties, but they are more prone to galvanic corrosion. Plasma electrolytic oxidation (PEO) coatings reinforced by nanoparticles have been shown to improve corrosion resistance and possess better mechanical properties. A lot of research has been published that focuses on the effect of nanoparticle concentration in the PEO electrolyte solution, and the type of nanoparticle, on the properties obtained. The aim of paper is to study the effect of processing time on the nanoparticle-reinforced PEO coating on AZ31 magnesium alloy. TiN and SiC nanoparticles were produced using plasma chemical synthesis and added to KOH-based electrolyte to develop PEO coatings. The concentration of nanoparticles was kept constant at 0.5 g/L and the treatment time was varied as follows: 1, 2, 3, 5, and 10 min. The coatings were tested for their microstructure, phase, chemical makeup, nano-mechanical properties, and corrosion resistance. Nanoparticles were found to be clustered in the coating and spread unevenly but led to a decrease in the size and number of pores on the PEO coating surface. The corrosion resistance and nano-mechanical properties of the coating improved with treatment time. The hardness and contact modulus of coatings with TiN particles were 26.7 and 25.2% greater than those with SiC particles. Addition of TiN nanoparticles resulted in improved corrosion resistance of the PEO coatings when the processing time was 5 or 10 min. The lowest corrosion rate of 6.3 × 10⁻⁵ mm/yr was obtained for TiN-added PEO coating processed for 10 min.

In the present work formation of active TiO₂ nanofibers in microwave-assisted synthesis and their modification with Au, Pt, Pd and Ag nanoparticles were studied. Anatase nanopowder and 10M KOH solution were used as raw materials. Microwave-assisted synthesis permitted to obtain TiO₂ nanofibers and nanowires with a diameter of 10nm and a specific surface area 158.5m²/g. Chemical deposition method were used to modify TiO₂ nanofibers with precious metal nanoparticles. After modification, specific surface area decreased and were in range 73.1 – 74.7m²/g. Photocatalytic activity was determined by degradation of the methylene blue (MB) solution under visible light irradiation. High intensity LED lamp was used as light source. The obtained samples showed higher photocatalytic activity with respect to pure TiO₂ nanofibers. The doped TiO₂ nanofibers were appropriate for degradation of harmful organic compounds as well as for hydrogen production by water splitting.