This study focused on the effect of heavy metal cobalt ions (at concentrations of 1–1000 ppm) on the development and enzymatic activity of four entomopathogenic fungi: Beauveria bassiana, Beauveria brongniartii, Isaria fumosorosea and Metarhizium robertsii, commonly used in biological plant protection. It was found that each of the tested species of fungi reacted individually to contact with the Co2+ ions at their various concentrations. Depending on the variants of the experiment carried out, there were changes in the development of the mycelia (mainly growth inhibition) and their morphological features (color and structure) in comparison to the control samples. Co2+ ions had a fungistatic effect on all fungal strains, whereas a fungicidal effect was noted at concentrations of 750 ppm and 1000 ppm against M. robertsii and I. fumosorosea, respectively. In addition, there was a discrepancy in enzymatic activity between the tested fungal species developing in the medium with varying concentrations of metal salt. The inhibitory effect of Co2+ ions on lipase production was observed in I. fumosorosea. Protease production was stimulated in B. bassiana at all Co2+ concentrations, whereas in M. robertsii this effect was noted at 1 ppm. The changing dynamics of extracellular fungal hydrolases, due to the action of Co2+ ions, may translate into the role of these microorganisms in the processes of insect pathogenesis. This work suggests that severe pollution of the environment by cobalt could be a restrictive factor for the development and pathogenicity of entomopathogenic fungi and must be taken into account for their successful application in biological plant protection.

Results of fly ashes from combustion of hard coal and co-combustion of alternative fuel (SRF) with coal in the stoker boiler WR-25 type studies have been shown. Samples of fly ashes were acquired during industrial combustion tests of hard coal and blend of coal with 10% SRF. The scope of comparative research included: chemical composition, contents of combustible parts and trace elements and also of microscopic analysis. The specific surface area SBET was established and tests of water extract were conducted. Chemical composition of mineral substance of both studied ashes is similar. Main ingredients are: SiO2, Al2O3, Fe2O3 and CaO. Fly ash from co-combustion of SRF with coal in a stoker boiler is characterized by high contents of combustible parts (on 30% level), higher than ash from hard coal combustion. Both tested ashes are characterized by specifi c surface area SBET on the level of 8–9 m2/g. In porous structure mesopores are dominant (>60%), and their volume is higher for fly ash from co-combustion of SRF with coal. Fly ash from co-combustion of waste is characterized by high contents of heavy metals. Nevertheless these metals and also other pollutants do not show leachability exceeding acceptable values for wastes different than hazardous. The microscopic structure of fly ashes from combustion of hard coal and co-combustion of alternative fuel studies showed crucial differences, especially in reference to organic material. Presented research results have shown that fly ash from co-combustion of SRF with coal in a stoker boiler can obtain the status of non-hazardous waste.

The article presents an assessment of the effects of anthropogenic activities on the quality of water in four streams flowing through a camp based on a combined assessment of environmental impacts and the water quality index. The quantitative and qualitative assessment of environmental impact was made after identifying the anthropogenic activities carried out in the camp. The water quality index ( WQI) was calculated after monitoring seventeen physicochemical and microbiological variables and the Montoya index was applied. The samples were collected during 48 sampling campaigns, organised over the period of six months in eight stations. Two stations were located in each stream, one before and one after it passed through the camp. The results indicated that streams 1, 3, and 4 show a slight deterioration in water quality, affected by anthropogenic activities carried out in the said camp; meanwhile, stream 2 shows an increasing deterioration in water quality. The water quality of the streams before passing through the camp was determined to be between “uncontaminated” and “acceptable”, while after passing through the camp it was classified between “acceptable” and “slightly contaminated”. The results indicated a non-significant difference between the downstream and upstream WQI values for streams 1, 3, and 4; while stream 2 did show a significant difference in the WQI between upstream and downstream; indicating that anthropogenic activities alter the quality of the water.