zeolite

Zeolites were added to polyethersulphone (PES) membranes in order to enhance their capability of attracting creatinine. Zeolite was blended with PES by varying its doping concentration and time, and the mechanical properties of the resulting hollow fibre membranes produced under optimal concentration were characterised. The values of tensile stress, tensile strain and Young’s modulus, as well as the flux and rejection of the membranes were determined.

Heavy metals in the environment are a source of some concern because of their potential reactivity, toxicity, and mobility in the soil. Zeolites have been used as a adsorbents to prevent potentially toxic metal contamination stemming from mining waste disposal. These materials are characterized by a high cation exchange capacity (CEC) and a predominance of negative charges, favoring their potential utilization in metal cation immobilization. It is widely used in laboratory research and industrial applications. Many physical and chemical processes occur at different interfaces.

Production of Portland cement is one of the most energy intensive among building materials, it is accompanied by significant CO2 emissions: 0,7 to 1 ton per 1 ton of cement, depending on manufacturing technology. Therefore, replacement of Portland cement clinker with active mineral additives of natural or synthetic origin is environmentally and economically viable, while not causing significant adverse changes in the properties of cement binders.

The results of research of the chemical activation process of clinoptilolite from Sokirnytskyi field are shown. As a result of the research, the effectiveness of the influence on zeolite hydrochloric and sulfuric acids are compared. It should be noted that the advantage is on the side of hydrochloric acid. It was established that the increase in the concentration of sulfuric acid and the time of zeolite processing leads only to the increase in the content of the amorphous phase.

The kinetics of copper ions adsorption by natural zeolite has been investigated in the apparatus with mechanical stirrer. The presence of external diffusion and pore diffusion area was established. For the external diffusive area, the dependence of mass transfer coefficient on stirrer rotation speed was confirmed; the dependence was described using a criterial equation. For the pore diffusion area, the equation is adduced by means of which the effective coefficient of pore diffusion was calculated.

It was established that natural and Ca modified zeolite inhibit steel corrosion in the medium of low acid rain. The Ca-containing zeolite inhibit the steel corrosion in the most effective way. The protective effectiveness of the alkyd coatings filled with zeolites can be placed in the following order:  unmodified < with natural zeolite < with Ca-containing zeolite.  Встановлено, що природний та модифікований кальцієм цеоліти інгібують корозію сталі в середовищі слабкокислих дощових опадів. Найефективніше інгібує корозію сталі Ca-вмісний цеоліт.

Concrete structures and elements are often exposed to different aggressive environment. It leads to failures, cracking, weathering and deterioration of concrete materials. Under aggressive conditions, the concrete is liable to a corrosive process which is not usually caused by one specific factor but by combination of aggressive media. Sulphur environment is one of the most corrosive factors influencing the concrete durability.

The beginnings of warm mix asphalt are connected with the use of foamed asphalt in the ‘60s of the last century. Asphalt foaming occurs by contact with water or water steam that can be entered mechanically or under pressure. The foaming effect can be also obtained by the adding of zeolite to the asphalt mixture which causes the lower viscosity of the asphalt, better workability and adhesiveness of the mixture to the aggregate in lower temperatures. Presently, synthetic zeolites Aspha-Min and Advera are used for reducing the processing temperature.

The aim of this article is to present the results of preliminary research of the damping parameters of vibration in the constructions with the addition of zeolite. The first part of the article deals with the characteristics and application of zeolite. It describes mainly the impact of the addition of zeolite on the concrete parameters. The main part of the article presents the research outcomes of the damping parameters of the three models of plate-beam.