The heavy metal contents and their bioavailability were monitored in soils of Central Spiš region of SR. This area belongs to long term contaminated and hygienically loaded areas. Soil contamination by heavy metals is caused especially by ore mining, processing and treatment. Soil samples from the Central Spiš contained higher proportions of mobile forms which corresponded to the following sequence Pb > Zn > Cu, while for mobilizable forms the sequence of investigated metals was as follows: Cu > Zn > Pb. Soil pH is one of the parameters that affect significantly the share of bioavailable forms of metals. Higher proportions of mobile fractions of metals were detected in samples taken from soils with acidic pH. Statistical processing confirmed a relationship between the percentage share of lead and zinc in the mobile form and the level of pH/KCl, which was significant for Zn: r = -0.53. The relationships for lead and copper were insignificant.

The formation of geopolymers from fly ash (FA) and metakaolin (MK) was investigated. The effect of different reactivity of FA and MK was studied by X‐ray photoelectron spectroscopy method. Geopolymer materials were obtained by an alkaline activation of aluminosilicate sources. The aim of this work is to develop methods for working properties prediction of geopolymer materials based on the starting materials. Selection of a geopolymerization scheme is found to be a key factor to realize a beneficial effect of improved reactivity. Finally, a descriptive model of the mechanism of geopolymer formation, taking into account the quality of starting materials was proposed. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 841–849, 2015

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Geopolymer materials are obtained by the alkaline activation of alumina-silicate sources, the best of which is metakaolin. The aim of this work is to develop methods for working properties prediction of geopolymer materials based on the starting materials-not only metakaolin. The formation of geopolymers from four types of fly ash samples (FA) from Slovakia derived from various combustion processes was investigated. Chemical bond changes during mechanical activation were examined by X-ray photoelectron spectroscopy (XPS). Formation of new Al-O-Si chemical bonds was detected by the changes in positions of Al and Si atoms during milling. Final mechanical strength achieved by mechanical activation was studied.

Biomass is organic material, the second most important source of energy. Biomass is a renewable energy source. Wood biomass is used as source of energy for heating in many regions in Slovakia. It is because of its availability. Wood biomass is an easily accessible and affordable source of energy. At present, thermochemical processes, biochemical processes and physical-chemical processes are used for biomass utilization. In the article a suitable technology for combustion of wood chips is proposed. It consists of five main technological parts: transport of wood chips, silo, combustion boiler, and stack.