The use of sewage sludge in agriculture decreases the pressure on landfills. In Romania, massive investments have been made in wastewater treatment stations, which have resulted in the accumulation of important quantities of sewage sludge. The presence of these sewage sludges coincides with large areas of degraded agricultural land. The aim of the present article is to identify the best technological combinations meant to solve these problems simultaneously. Adapting the quality and parameters of the sludge to the specificity of the land solves the possible compatibility problems, thus reducing the impact on the environment. The physico-chemical characteristics of the fermented sludge were monitored and optimal solutions for their treatment were suggested so as to allow that the sludge could be used in agriculture according to the characteristics of the soils. The content of heavy metals in the sewage sludge was closely monitored because the use of sewage sludge as a fertilizer does not allow for any increases in the concentrations of these in soils. The article identifies those agricultural areas which are suitable for the use of sludge, as well as ways of correcting some parameters (e.g., pH), which allow the improvement of soil quality and obtained higher agricultural production.

In this work, the corrosion resistance of hybrid coatings obtained from plastic materials was evaluated and compared with the corrosion resistance of Zn coatings. Zinc and hybrid coatings were obtained by electrodeposition from zinc sulphate electrolyte. For obtained hybrid coatings it was used as disperse phase two type of plastic materials: phenol-formaldehyde resin and epoxy resin. Polarization was used to measure the corrosion rate and behaviour of zinc and hybrid coatings in 3.5% NaCl solution. Tafel curves show that the including particles of plastic materials in zinc matrix disturbs the cathodic reactions and reduces anodic reaction leading to decrease of corrosion current and increase the corrosion resistance of hybrid coatings obtained at the same electrodeposition parameters as zinc coatings. Smallest values of corrosion rate were evaluated for hybrid coatings obtained with phenol-formaldehyde resin as disperse phase that indicates a good corrosion resistance in 3.5% NaCl solution.

One of the objectives of the circular economy is solving the world’s plastic pollution crisis and recycling of materials by ensuring less waste. The motivation of this study was to demonstrate the possibility of recycling two types of wastes with a high risk of pollution, such as plastic based polypropylene and abrasive blasting grit wastes in asphalt roads. The effects of adding together polypropylene based microplastics and grit waste in asphalt mixture for wear layer performance have been shown in this study. The morphology and elemental composition of the hot asphalt mixture samples before and after freeze–thaw cycle were examined by SEM–EDX and the performance of the modified asphalt mixture was determined with laboratory tests including Marshall stability, flow rate, solid–liquid report, apparent density, and water absorption. A hot asphalt mixture suitable for making wear layer in road construction, containing aggregates, filler, bitumen, abrasive blasting grit waste and polypropylene based microplastics is also disclosed. In the recipe of modified hot asphalt mixtures were added 3 proportions of polypropylene-based microplastics such as 0.1%, 0.3% and 0.6%. An improvement of the mixture performance is shown at the asphalt mixture sample with 0.3% of polypropylene. In addition, polypropylene-based microplastics are bond with aggregates from mixture well, so the polypropylene-modified hot asphalt mixture can effectively decrease the appearance of cracks during sudden temperature changes.

The aim of the present work is to identify the expected nearshore and offshore impact of a marine energy farm that would be implemented in the coastal environment of Portugal. Several layouts of Wave Dragon devices were considered, the distance between each system being gradually adjusted. By processing 27–years of combined wave data coming from the European Space Agency and ERA5, the most relevant conditions have been identified. The centre of each farm layout was set to approximately 3.5 km from the coast, where a more significant attenuation of wave heights in the middle of the target area was noticed, which can go up to 16% in the case of extreme events. From the analysis of the longshore currents, it was noticed that even an arrow farm layout defined by five systems may have a significant impact, by changing the peak or by smoothing the currents profile. Wave energy is an emerging renewable sector that can also contribute tocoastal protection and, therefore, the Portuguese coast represents a suitable candidate for this type of project.

The materials used in additive techniques are initially in a plastic state so that they can be inserted into various cavities or easily molded after which they pass into a rigid phase. This process is performed by various methods, depending on the nature of the material. The study aims at analyzing the chemical and biological behavior of flexible acrylates compared to classical acrylates, whose structure was optimized through the introduction, at a structural level, of certain polymeric and antiseptic structures in view of obtaining a high degree of biocompatibility, the elements of variability consisting in the difference between the two polymerization regimes, the polymerization under pressure and the classical polymerization.The polymerization of acrylic resins by the technique of thermobaro-polymerization with injection compensation leads to the formation of materials with superior impact resistance. The pressure regime is very important, being a factor that influences the polymerization without being initiated. Breaking strength is an essential element in assessing the quality and duration of the prosthesis use.