The particle shape and size of the starting powders represent the most important physical properties, on which the quality of the compacts and final sintered products depends. Two types of powder were analyzed in the paper - electrolytic copper powder with a dendritic particle shape and water-atomized copper powder with an irregular particle shape. The starting powders were sieved through a sieve system with openings of 45 μm, 80 μm, and 120 μm. The characterization of the obtained fractions of both powders was performed by determining the shape and dimensions of the particles using SEM microscopy in combination with ImageJ software, and the apparent density and flow rate were determined using the Hall flowmeter funnel. Pressing of each powder fraction was done using a pressure of 600 MPa. The compacts were further sintered at 1000°C for 2 hours to obtain the final sintered parts. After sintering, their density, hardness, and electrical conductivity were determined and their microstructure was analyzed. The results indicate a great influence of the characteristics of the starting powders on the properties of the final parts obtained by the powder metallurgy route. The particle shape of the powders had a more pronounced influence compared to the particle size.

Due to the very complex composition of leachate wastewater, combining two or more physical, chemical, or biological processes, carried out simultaneously or sequentially, is highly needed in order to obtain effluent suitable for further discharge into sewage. In this paper, electrocoagulation coupled with synthetic zeolite (EC-NaX), electrocoagulation coupled with ultrasound (EC-US), and two steps electrocoagulation (EC-1st and EC-2nd) were tested for compost leachate treatment, with very high initial organic loading and acidic pH. The comparison of each process was done in regard to the following parameters: pH, electrical conductivity and temperature change, removal percentage of chemical oxygen demand (COD), turbidity, total solids change, settling ability, and electrode consumption. Results highlight the EC-NaX as the best option for the treatment of compost leachate, due to the highest removal percentage of COD (51.91%), satisfactory removal percentage of turbidity (97%), good settling abilities, and lowest electrode consumption. However, the final COD values in the effluent are still significantly high for further discharge into sewage systems, thus additional treatment needs to be applied. Also, the final acidic pH, high values of electrical conductivity, and high temperature of effluent need to be solved in further treatment steps.

Due to the fast process of urbanization and the increase in the development of transport infrastructure, there is an increase in noise levels caused by road and railway traffic in urban areas, which represents one of the most important today's problems. The goal of this paper is to find out the current noise levels of road and railway traffic. Measuring road traffic noise levels in the area of the city of Zenica and the railway traffic noise in the vicinity of the Railway Station in Kakanj has been done. In the end, the analysis of the obtained results and comparisons with the values regulated by the law as allowed values were performed. Noise level maps were also plotted as one of the contributions to solving the problem of environmental noise.