RESUMEN
In some locations around the globe, the U concentrations may exceed WHO standards by 2-folds therefore, effective yet environmentally wise solutions to purify radioactive waters are of significant importance. Here, the optimized and fully controlled coal-fly-ash based Na-P1 zeolite functionalization by employing novel, biodegradable biosurfactant molecule - cocamidopropyl betaine (CAPB) is showcased. The zeolite's surface decoration renders three composites with varying amounts of introduced CAPB molecule (Na-P1 @ CAPB), with 0.44, 0.88, and 1.59-times External Cation Exchange Capacity (ECEC). Wet-chemistry experiments revealed extremely high U adsorption capacity (qmax = 137.1 mg U/g) unveiling preferential interactions of uranyl dimers with CAPB molecules coupled with ion-exchange between Na+ ions. Multimodal spectroscopic analyses, including Fourier-Transformed Infra-Red (FT-IR), X-ray Photoelectron (XPS), and X-ray Absorption Fine Structure (XAFS), showed the hexavalent oxidation state of U, and no secondary release of the CAPB molecule from the composite. The EXAFS signals fingerprint changes in the interatomic distances of adsorbed U, showing the impact of the O and N, heteroatoms present in the CAPB molecule on U binding mechanism. The presented research outcomes showcase the easy, scalable, optimized, and environmentally friendly synthesis of biofunctional zeolite effectively purifying the real-life U-bearing wastewaters from the vicinity of the Pribram deposit (Czech Republic).
RESUMEN
The response of potato plants to organo-mineral fertilization is still poorly understood. Hence, the aim of this study was to evaluate absorption and extraction of micronutrients by Agata potato cultivar in winter crop. The experiment was conducted in the municipality of Cristalina, Goiás state, Brazil, from May 26 to August 29 of 2012. The experimental design was a randomized block with five organo-mineral fertilizer rates, one mineral fertilizer rate (control) and four replications for each treatment. The results demonstrated that the mean total absorption of micronutrients by potato plants for the organo-mineral treatments was higher relative to the mineral treatment; and also that micronutrients were absorbed in the following order: Fe> Zn>Mn> Cu> B, in relation to total amounts. The average export of micronutrients in potato plants treated with organo-mineral fertilizer was 28%, 37%, 25%, 8% and 17% for Cu, Fe, Mn and Zn (respectively)relative to total amounts absorbed by the plants.
A resposta das plantas de batata à adubação organo-mineral ainda é pouco conhecida. Assim, o objetivo deste estudo foi avaliar a absorção e extração de micronutrientes por cultivar Agata de batata na safra de inverno. O experimento foi conduzido no município de Cristalina, Goiás, Brasil, de 26 de maio a 29 de agosto de 2012. O delineamento experimental foi um bloco casualizados com cinco doses de fertilizantes organo-minerais, uma dose mineral de fertilizante (controle) e quatro repetições para cada tratamento .Os resultados demonstraram que a absorção total média de micronutrientes por plantas de batata para os tratamentos organo-minerais foi maior em relação ao tratamento mineral, e também que os micronutrientes foram absorvidos na seguinte ordem: Fe> Zn>Mn> Cu> B, em relação às quantidades totais. A exportação média de micronutrientes em plantas de batata tratadas com adubo organo-mineral foi de 28%, 37%, 25%, 8% e 17% para Cu, Fe, Mn e Zn (respectivamente) em relação às quantidades totais absorvidas pelas plantas.