Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 2025

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Solidification/stabilization of fly ash contaminated with radiocaesium into geopolymers

Rezbárik Šimon, Vavrincová Lenka, Valica Martin, Adamcová Vanda, Sekely Stanislav, Rezbárik Ján, Horník Miroslav

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

2025

Vol. 34, No. 1

55--72

The main goal of this work was to evaluate the possibilities of solidifying fly ashes contaminated with 137Cs into geopolymer waste forms. In the first step, physico-chemical characterization of fly ash originating from the thermal power plant in Vojany (Slovak Republic) was carried out. Before the preparation of the geopolymer waste forms (ternary mixture Geocem, GEOFIX, s.r.o., Slovak Republic) containing fly ash at percentage weight proportions of 5%, 10%, 20%, and 40%, the fly ash was artificially contaminated with a 137CsCl solution. The 137Cs activity was measured by scintillation gamma-spectrometry. The leachability test conducted according to the American National Standard ANSI/ANS-16.1-1986 over five days showed that the geopolymer waste forms with fly ash contents of 5%, 10% and 20% met the required leachability index limits with values more than 6. The compressive strength test also confirmed that the samples with 40% ash content did not meet the required 5 MPa limit for their disposal as a radioactive waste.

Effect of soil nutrients on the stability of superabsorbent polymers as a tool for climate change mitigation

Vavrincová Lenka, Adamcová Vanda, Machalová Linda, Valica Martin, Rezbárik Šimon, Horník Miroslav

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

2025

Vol. 34, No. 1

73--88

The aim of this study was to assess the effect of soil nutrients on the stability of superabsorbent polymers (SAPs). In agriculture, SAPs are known to increase productivity in arid regions by improving plant water availability, optimizing root nutrient uptake, and increasing plant drought tolerance. In this study, we tested SAPs derived from starch and mixtures of acrylic acid and acrylamide. First, a physicochemical characterization of the SAPs was performed, which included optimizing the water absorption volume, determining the maximum absorption capacity, and analyzing the water binding kinetics. We then also investigated the effects of elements, such as Na, K, Zn and Cu, on the stability of SAPs. The results showed that the SAPs exhibited a high-water absorption capacity. However, reduced swelling capacity was observed in the presence of Hoagland’s medium and solutions of metal ions (Na, K, Zn, Cu) with equimolar concentrations to potassium in the SAP.