Search results for "leaching"
showing 7 items of 267 documents
Design and Characterization of Effective Ag, Pt and AgPt Nanoparticles to H2O2 Electrosensing from Scrapped Printed Electrodes
2019
The use of disposable screen-printed electrodes (SPEs) has extraordinarily grown in the last years. In this paper, conductive inks from scrapped SPEs were removed by acid leaching, providing high value feedstocks suitable for the electrochemical deposition of Ag, Pt and Ag core-Pt shell-like bimetallic (AgPt) nanoparticles, onto screen-printed carbon electrodes (ML@SPCEs, M = Ag, Pt or AgPt, L = metal nanoparticles from leaching solutions). ML@SPCEs were characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The results were compared to those obtained when metal nanoparticles were synthesised using standard solutions of metal salts (MS@…
Acetic acid leaching of neodymium magnets and iron separation by simple oxidative precipitation
2022
Neodymium-iron-boron (NdFeB) has become the most prominent permanent magnet alloy, with a wide variety of applications and an ever-increasing demand. Their recycling is important for securing the supply of critical raw materials used in their manufacturing. The use of organic acids such as acetic acid has been of recent interest for the recycling of waste NdFeB magnets. Despite achieving good leaching efficiencies, the published literature has not properly investigated the effects of key factors influencing the acetic acid leaching process and their respective interactions, which has lead to conflicting findings as to what conditions are optimal. The present work goes to show that no such o…
Dynamika uwalniania azotu z nawozów o powolnym działaniu w eksperymencie laboratoryjnym
2016
Sustainable fertilization is one of the most important treatments of modern agriculture. Organic agriculture with new demands on agricultural practice, seeks to restrict the use of mineral fertilizers in favor of slow-action organic fertilizers. The fertilizers which are made on the farm are particularly valuable due to their quality and the absence of costs of purchase and transport. From this point of view, the new possibilities of using an organic matter which comes from waste of the food industry or biodegradable wastes from households proves to be interesting. Due to the absence of contamination with other types of waste, it can be used for the production of a fertilizer which could be…
Naturalne spoiwa kostek nawozowych jako element zrównoważonej uprawy roślin
2016
Zrównoważona uprawa roślin, stawiająca nowe wymagania praktyce rolniczej, dąży do ograniczania wykorzystania nawozów mineralnych na rzecz długo działających nawozów organicznych. W szczególności cenne są te nawozy, które powstają w obrębie gospodarstwa z uwagi na ich wysoką jakość oraz brak kosztów związanych z zakupem i transportem. Zwłaszcza materia organiczna zawarta w odpadach przemysłu spożywczego lub powstająca w gospodarstwach domowych, przy braku zanieczyszczeń innymi rodzajami odpadów, może służyć do wytwarzania nawozu, który mógłby być wykorzystywany nawet w organicznej produkcji roślin uprawnych. W pracy przedstawiono wyniki badań wiązania organicznych i mineralnych komponentów n…
Iron and pH regulating the photochemical mineralization of dissolved organic carbon
2017
Solar radiation mineralizes dissolved organic matter (DOM) to dissolved inorganic carbon through photochemical reactions (DIC photoproduction) that are influenced by iron (Fe) and pH. This study addressed as to what extent Fe contributes to the optical properties of the chromophoric DOM (CDOM) and DIC photoproduction at different pH values. We created the associations of Fe and DOM (Fe-DOM) that cover the range of loadings of Fe on DOM and pH values found in freshwaters. The introduced Fe enhanced the light absorption by CDOM independent of pH. Simulated solar irradiation decreased the light absorption by CDOM (i.e., caused photobleaching). Fe raised the rate of photobleaching and steepened…
Photobleaching and Recovery Kinetics of a Palette of Carbon Nanodots Probed by In Situ Optical Spectroscopy
2022
Carbon dots (CDs) are a family of fluorescent nanoparticles displaying a wide range of interesting properties, which make them attractive for potential applications in different fields like bioimaging, photocatalysis, and many others. However, despite many years of dedicated studies, wide variations exist in the literature concerning the reported photostability of CDs, and even the photoluminescence mechanism is still unclear. Furthermore, an increasing number of recent studies have highlighted the photobleaching (PB) of CDs under intense UV or visible light beams. PB phenomena need to be fully addressed to optimize practical uses of CDs and can also provide information on the fundamental m…