The photocatalytic activity of three systems, promising for chemical water purification technologies, was experimentally compared, based on a combination of titanium dioxide/(Fe(II, III)), applying ...to the model oxidation reaction of methylorange organic dye in an aqueous medium. Herewith the cases of photocatalytic systems were investigated, which are based on: a) titania hydrosol obtained by hydrolysis of titanium isobutylate; b) a similar hydrosol with addition of Fe(III) ions; c) suspension of ilmenite powder based on FeTiO
3
. As a result of the investigation, the increase of the rate of destruction of methylorange by more than two times was found in the system with the introduction of a small amount of iron ions into initial suspension of the TiO
2
hydrosol (at the obtaining a medium with the Fe
3+
concentration up to 3.7 × 10
–5
M). In the photocatalytic system, based on the suspension of pretreated (with suphation and calcination) ilmenite powder, enough high photocatalytic activity (the degree of methylorange decomposition up to 77 %) was measured but at a higher exposure than for the case of systems based on the TiO
2
hydrosol. For the photocatalytic systems of the type being investigated, a possible mechanism of increasing their oxidative activity was briefly considered, which requires an additional physico-chemical analysis.
The paper considers an effect of ZrO2 content in 20%Co/xZrO2∙(100 – x)SiO2 (x = 0, 10, 15, 25, 30, 40 and 100 mass percent) catalyst carriers on their catalytic properties. Temperature programmed ...desorption of NH3 has made it possible to determine relations between their acid and catalytic properties. The paper reveals the TPD spectrum is the result of 4 overlapping peaks originating during NH3 desorption from the respective groups of acid sites. Total acidity of samples and contribution of separate acid site groups into the given acidity have been have been determined in the paper. The paper contains graphical dependences of a various-type acid site number on content of zirconium oxide in the carrier. Correlations between change in various-type acid site number and catalytic process parameters (CO conversion, C5+ hydrocarbon output and C5+ isoparaffin output) have been found in the paper. The paper shows that the highest values of CO conversion and C5+ hydrocarbon output correspond to maximum number of acid sites, and that number accounts for a peak of desorbed ammonia at Tmax = 122 °C, while the lowest isoparaffin output corresponds to minimum number of acid sites, which characterizes a peak of desorbed ammonia at Tmax = 224–257 °C.
The paper present results concerning determination of quantitative composition of soap stock while using methods for centrifugal concentration and fractional separation. Gas chromatography analysis ...data on soap stock are obtained in the paper. An isolation of higher fatty acids have been executed and their sodium, potassium and zinc salts have been obtained in the research. Dependence of the surface tension of potassium soap water solutions on concentration has been studied and potassium soap surface activity has been determined in the paper.
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