This paper deals with adsorption of a cationic dye – methylene blue - on the activated biocarbon obtained via chemical activation of horsetail herb post-extraction residue. The effects of initial dye concentration, temperature, solution pH, as well as the phase contact time on the adsorption effectiveness have been tested. The adsorbent prepared was characterized based on the results of elementary analysis, surface area measurements, thermal analysis as well as determination of the acid-base nature of its surface. It has been shown that micro/mesoporous horsetail herb-based activated biocarbon exhibits a significantly higher ability to methylene blue uptake than the commercial activated carbon prepared from peat. It has been also found that the adsorption capacity increases with the increasing initial dye concentration in the solution and the phase contact time. The maximum adsorption toward methylene blue was found at pH=12 and at temperature of 40 C. A better fit to the experimental data was obtained with a Langmuir isotherm than Freundlich one, whereas better fit of the kinetic data was achieved using the pseudo-second order model.
A series of new synthetic carbonaceous adsorbents has been prepared via physical and chemical activation of residue of alcoholic fermentation of corn starch. Two different variants of thermal treatment procedure - microwave and conventional heating have been applied for preparing of the activated biocarbons. All the samples under investigation were characterised by elementary analysis, surface area measurements as well as determination of the number of surface functional groups. The electrokinetic properties of examined materials were studied using potentiometric titration and electrophoresis methods, which enabled determination of the surface charge density and zeta potential of activated biocarbon particles. Moreover, sorption properties of the carbonaceous materials towards two organic dyes - methylene blue and malachite green were tested. The final products were activated biocarbons of medium developed surface area ranging from 21 to 879 m2/g, showing acidic character of the surface and various content of surface functional groups. More favourable textural parameters as well as sorption properties toward both organic dyes were revealed by chemically activated samples. The obtained results indicated also considerable effect of adsorbed dye molecules on the structure of electrical double layer formed at the solid/liquid interface.
The materials under investigation were new carbon-nitrogen composites obtained via pyrolysis and CO2 activation of sweet drinks destined for utilization. Waste Pepsi Cola® has been examined as an alternative and renewable carbon source for composite materials. Nitrogen was introduced into the Pepsi Cola® solution via the addition of guanidine carbonate, before the pyrolysis process. The physicochemical properties of the materials studied were characterized by low- temperature nitrogen adsorption (using BET and BJH methods), elemental analysis, FTIR spectroscopy, scanning electron microscopy (SEM) as well as determination of pHPZC and the number of surface functional groups. Additionally, thermal properties of the samples were investigated by thermogravimetric analysis (TG) and differential thermogravimetry (DTG). The final products were new carbon-nitrogen composites characterized by a very high content of nitrogen (11.2 - 21.6 wt.%) as well as relatively low surface area and pore volume reaching 198 m2/g and 0.16 cm3/g, respectively. Results of FT-IR study and Boehm titration indicated that the composites surface has clearly basic character, which was confirmed by pHpzc values above 8.0.
Budownictwo infrastrukturalne stanowi dużą część sektora budowlanego. W jego skład wchodzą wszystkie elementy sieci transportowej, użytkowane przez środki transportu. To właśnie ten zestaw nazywamy infrastrukturą. W ramach ogółu projektu wyróżniamy szereg elementów takich jak: obiekty mostowe, MOP-y (Miejsca Obsługi Podróżnych) czy ciągi komunikacyjne dla pieszych. Infrastruktura towarzysząca stanowi coraz ważniejszą, a niestety często pomijaną w dyskusjach różnych środowisk budowlanych część całości. Ze względu na wysokie wymagania dotyczące trwałości i jakości wyrobów, przeważająca część z nich jest wykonywana z betonu. To właśnie tej „cegiełce” w ogóle inwestycji poświęcony jest poniższy artykuł.
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