Wherein lies the essence of the two-year dispute over the management and protection of the commercial forest stands in the Białowieża Primeval Forest?

The quantitative description of an airlift bioreactor, in which aerobic biodegradation limited by carbonaceous substrate and oxygen dissolved in a liquid takes place, is presented. This process is described by the double-substrate kinetics. Mathematical models based on the assumption of plug flow and dispersion flow of liquid through the riser and the downcomer in the reactor were proposed. Calculations were performed for two representative hydrodynamic regimes of reactor operation, i.e. with the presence of gas bubbles only within the riser and for complete gas circulation. The analysis aimed at how the choice of a mathematical model of the process would enable detecting the theoretical occurrence of oxygen deficiency in the airlift reactor. It was demonstrated that the simplification of numerical calculations by assuming the “plug flow” model instead of dispersion with high Péclet numbers posed a risk of improper evaluation of the presence of oxygen deficiency zones. Conclusions related to apparatusmodelling and process design were drawn on the basis of the results obtained. The paper is a continuation of an earlier publication (Grzywacz, 2012a) where an analysis of single-substrate models of the airlift reactor was presented.

Jaki charakter ma toczący się od dwóch lat spór o sposób postępowania gospodarczego i ochronnego w lasach gospodarczych Puszczy Białowieskiej?

This paper presents a method of describing an airlift bioreactor, in which biodegradation of a carbonaceous substrate described by single-substrate kinetics takes place. Eight mathematical models based on the assumption of liquid plug flow and axial dispersion flow through the riser and the downcomer in the reactor were proposed. Additionally, the impact of degassing zone with assumed complete mixing on the obtained results was analyzed. Calculations were performed for two representative hydrodynamic regimes of reactor operation, i.e. with the presence of gas bubbles only within the riser and for complete gas circulation. The conclusions related to the apparatus design and process performance under sufficient aeration of the reaction mixture were drawn on the basis of the obtained results.

The paper presents application of differential electronic nose in the dynamic (on-line) volatile measurement. First we compare the classical nose employing only one sensor array and its extension in the differential form containing two sensor arrays working in differential mode. We show that differential nose performs better at changing environmental conditions, especially the temperature, and well performs in the dynamic mode of operation. We show its application in recognition of different brands of tobacco

Catalytic properties of activated carbons oxidized, treated with N-compounds, and promoted with copper were studied in selective catalytic reduction NOX by ammonia (NH3-SCR). The modification of the catalysts consisted of a series of steps (pre-oxidation of activated carbon, impregnation with urea, impregnation with copper). The physicochemical properties of the obtained samples were determined using X-ray diffraction, FT-IR spectroscopy, and low-temperature N2 sorption. The modification with copper improved the catalytic activity and stability of the catalysts. All the functionalized carbon doped with copper reached more than 90% of NO conversion and CO2 did not exceed 240 ppm at 220 ◦C. The sample doped with 5 wt.% Cu had the maximum NO conversion of 98% at 300 ◦C. The maximum N2O concentration detected for the same sample was only 55 ppm, which confirmed its selectivity.