In a period of industrial expansion, protection of the environment is often neglected during the mass manufacture of products. One of the problems of our society that is necessary to face at present is the provision, processing and then usage of waste composed of fine particles that are extremely dangerous for mankind. This study looks at the processing of the fine dust resulting from the manufacture of brake pads. The selected technologies for the process of dust treatment were compaction, extrusion and tumbling granulation, and their consequent comparison with the strength of a break and disintegration of agglomerates from fine dust. The experiments were performed on a unique equipment that made it possible to process such dust in the form of larger units and thus reduce their dustiness, with this dust being reintroduced into the technologies for repeat processing or used for energy processing, in a cement kiln, for example.

The aim of this paper was to describe the influence of high-shear wet granulation process parameters on tablet tensile strength and compaction behavior of a powder mixture and granules containing hydralazine. The hydralazine powder mixture and eight types of granules were compacted into tablets and evaluated using the Heckel, Kawakita and Adams analyses. The granules were created using two types of granulation liquid (distilled water and aqueous solution of polyvinylpyrrolidone), at different impeller speeds (500 and 700 rpm) and with different wet massing times (without wet massing and for 2 min). Granulation resulted in improved compressibility, reduced dustiness and narrower particle-size distribution. A significant influence of wet massing time on parameters from the Kawakita and Adams analysis was found. Wet massing time had an equally significant effect on tablet tensile strength, regardless of the granulation liquid used. Granules formed with the same wet massing time showed the same trends in tabletability graphs. Tablets created using a single-tablet press (batch compaction) and an eccentric tablet press showed opposite values of tensile strength. Tablets from granules with a higher bulk density showed lower strength during batch compaction and, conversely, higher strength during eccentric tableting.

Surface water and groundwater are polluted with pharmaceuticals, detergents, pesticides, and many other substances. Application of ferrates seems to be a perspective option for wastewater treatment as ferrates are not only powerful oxidizing agents but also an excellent disinfecting and coagulating agents decomposing many stable inorganic, organic, and biological compounds. Final products of their decomposition do not include carcinogenic or toxic products. In this paper, stability of electrochemically prepared potassium ferrate encapsulated in packaging materials printed on a 3D printer was monitored. In the experiment, electrochemically prepared potassium ferrate with different purity (21.4 %, 63.5 % and 67.3 %) was used. Stability of potassium ferrate was monitored for one month and that of other ferrates for three months. Different storage conditions of ferrate samples were also compared. Storage conditions had a significant influence on the ferrate stability.