Key Engineering Materials Vol. 838

Abstract: In industrial composting, a large scale of technological processes and devices is used which, to a certain extent, influence also the quality and characteristics of final substrates. Composts are, on the basis of the existing legislation, compared from the point of view of content of hazardous elements, qualitative characteristics, content and quality of humic substances, their impact on germination capacity and the subsequent growth of plants.

Abstract: In view of the dynamic development of electrical and electronic equipment and the reduction of its lifetime, the share of electronic equipment that has become waste has risen. In proportion to this situation, there is a constant improvement in separating industrial methods aimed at removing hazardous components of electrical waste (PCBs containing condensers, mercury switches or asbestos insulation). Another commodity, and economically more interesting, is the obtaining of the utility component of the waste iron and non-ferrous metals. After the separation of the interesting components what remains is a heterogeneous mixture of plastic pulp, which is usually landfilled or incinerated in the waste incinerator. This leads to the loss of valuable material, which could be further exploited. The paper deals with the issue of the disposal of plastics from electrical waste and its subsequent use as plastic pulp, which can be used to fill the rainwater detention reservoir.

Abstract: The paper presents the results of the evaluation of the environmental potential of soils in the area affected by the long-term mining activity. The environmental potential index consists of a numerical expression of the ability to provide water storage, immobilization of risk elements, and immobilization and transformation of organic pollutants. The exceedance of the limit values Hg, Cu, Zn, As, Cd and Pb was found in the soils of the investigated area of central Spiš. The rate of soil immobilization of risk elements is very low to high. The point value expressing the ability of agricultural lands to provide environmental functions is very low to medium in the studied areas, the financial expression of the values of the environmental potentials indexes is in the range of 7 100 to 14 000 € ha^-1, while the average value of 1 ha of agricultural land in Slovakia is about 14 200 €.

Abstract: The paper is focused on the topic of phytoremediation. The experiment included planting chosen plants (perennial ryegrass, chives and garden cress) into mixed homogenised mixture which in all cases contained substrate, compost and contaminated soil (sleeper subsoil) in ratios 60 : 20 : 20. The soil mixtures were analysed after the end of flowering. The results show that the most suitable compost was vermicompost of the brand EKOVERMES. The plants included a convenient choice of perennial ryegrass and garden cress.

Abstract: The paper deals with laboratory testing of PAHs biodegradation in samples of sleeper subsoil via two chosen microorganisms, bacteria Pseudomonas monteilii and Rhodococcus degradans. The obtained results show that the pure bacterial culture R. degradans removed 46 % PAHs in 28 days. Bacterium P. monteilii was far more successful in degrading PAHs, it managed to remove 74 % PAHs. The worst result was from the mixture of both bacteria which degraded only 34 % PAHs.