On the basis of the analyses of various types of power industry wastes, the research in the second stage of the project was focused on the
- study of the wastes from power plants burning black coal (namely black-coal ashes)
Obtained results confirmed some effect of the action of tested microorganisms (MO) on the elemental composition of treated ashes. The selectivity of the biological-chemical extraction of the elements doesn’t reach degree utilizable for commercial treatment of silicate module of leached coal ashes. Considering the elemental distribution of treated ashes the useful ignition residue concentrates in the fractions above 0,04mm.
- study of waste mud from the production of power coal
The results of the study brought original pieces of knowledge regarding destruction of coal matrix with selected species of soil microorganisms. Biodegradation of coal mass resulted in the production of humic acid-type substances. These substances are applicable in variety of ecological technologies in agriculture, medicine and further branches.
- study of the wastes from tyre combustion and pyrolysis
A new and effective process of dissolution and extraction of zinc from pyrolytic smut was developed. This step facilitates complex recycle of used tyres.
- study of the biodegradation of polycyclic aromatic hydrocarbons (PAH) from soils contaminated by coal tar
Biodegradation of soils contaminated with high concentrations of PAHs is studied in laboratory microcosms simulating natural conditions. Monitoring of biodegradation using on-line respirometric measurements is combined with chemical, toxicological and microbial analysis of exposed samples. Biodegradation proceeds well in aerobic conditions with adopted microbial co-culture, reaching significant diminution of initial PAH contamination.
A significant part of research capacities was carried in publication activities resulting in authoring of 1 foreigner monograph and of 5 scientific artickes presented on international conferences. One of the article was awarded by scientific committee of World Congress in Pittsburgh.
The preparation of nano-antimony (particles with grain size of 19 nm) by high-power grinding of antimony sulphide Sb2S3 with elementary iron Fe as a reducer has realised. Mechanochemical reduction was carried out in laboratory planetary mill. The composition and properties of nano-powders prepared by high-power grinding were determined by XRD, VSM and TEM. The process of synthesis is direct, during the reaction solid products originate only, namely elementary antimony Sb (JCPDS 05-0562) and FeS (pyrhotín-4H, JCPDS 22-1120). The kinetics of mechanochemical reduction, described by the methods of XRD and VSM shows, that more than 80% of reduction carried out after 60 minutes of grinding. The time of 180 minutes was needed for complete reaction. Contrary to classical high temperature reduction, atmospheric pressure and laboratory temperature are sufficient conditions for this process.
The study of physical and physico-chemical properties of iron-oxides-based sorbents and their application in heavy metal removal from waters was also the aim of this theme. The following materials were tested: synthetic magnetite, prepared by precipitation of Fe2+ and Fe3+ salts under laboratory condition and so called Albanian (ore origin) leaching residuum from former Nickel Works in Sereď. The main component of this residuum is represented by synthetic magnetite, which arise from goethite and lepidocrocite being occurred in original laterite ore. The introduced materials were used as sorbents of bivalent ions of cadmium, lead, copper and zinc. It was proven, that a significant amount of heavy metals ions from model solutions was removed. The adsorption capacities of synthetic magnetite were as follows: 64 mg.g1 for Cd at pH 7; 54 mg.g-1 for Pb at pH 4,5; 16 mg.g-1 for Cu at pH 4,5 and 56 mg.g-1 for Zn at pH 6. The values of sorption capacity demonstrate decreasing affinity of synthetic magnetite to individual heavy metals in the series Cd > Zn > Pb > Cu. The adsorption capacities of Albanian leaching residuum were 30 mg.g-1 for Cd at pH 7 and 42 mg.g-1 for Zn at pH 7. The highest efficiency of metals removal process (over 50%) was attained in the interval of low initial concentration of theses components in solution (20-100 mg.L-1). The efficiency rapidly falls down at increasing initial concentration.
The theme was solved in co-operation with the Department of mechanics and mechatronics, Faculty of mechanical engineering, Technical University Kosice. The stress distribution in disintegration tool and disintegrated rock were modelled in static analysis. Acoustic signal
decoding in frequency domain provides identification of control variable for the rock disintegration process. State-of-the-art: Determinative factor in rock disintegration by rotary drilling is a shear stress.
Combination of thrust and torque induces a stress field formation which supports the rock chipping. Within the intelligent system proposal for identification of various rock types, a frequency zoom and vector quantisation were used as methods for recognition of accessory acoustic
signals by disintegrated rock type.
(Following results within the SPVV solution: 1 monograph, 2 publications in CC journals, 3 publications in NCC journals, 10 publications in conference proceedings, 10 product innovations, 7 process innovations, 1 organizational and 1 marketing innovation)