Search results for "typpi"
showing 9 items of 59 documents
Separation of palladium and silver from E-waste leachate : effect of nitric acid concentration on adsorption to Thiol scavenger
2022
The development of recovery techniques for metals present in low concentrations in E-waste, such as silver and palladium, is important from the aspect of the circular economy. Adsorption of palladium and silver was studied in detail in a batch process with silica-based Thiol scavenger from nitric acid leachate of waste printed circuit boards (PCBs). High adsorption efficiencies of Pd(II) and Ag(I), >97%, were reached in nitric acid concentrations below 3 mol L−1. At higher acid concentrations, adsorption efficiency of Ag(I) decreased drastically which enables the separation of Ag(I) and Pd(II) based on nitric acid concentration in sample solution. Pd(II) and Ag(I) followed pseudo 2nd order …
Removal of ammonium ions from aqueous solutions using alkali-activated analcime as sorbent
2023
Five alkali-activated analcime (ANA) sorbents (ANA-MK 1, ANA 2, ANA 3, ANA-MK 4, and ANA-MK 5) were developed for ammonium (NH4+) ion removal. Acid treatment and calcination were used as pre-treatments for analcime, and metakaolin (MK) was used as a blending agent in three sorbents. Sorption experiments were performed to evaluate the effects of sorbent dosage (1–20 g L−1), initial NH4+ ion concentration (5–1000 g L−1), and contact time (1 min–24 h). ANA-MK 1, ANA 2, and ANA-MK 4 were the most efficient sorbents for NH4+ ion removal, with a maximum experimental sorption uptake of 29.79, 26.00, and 22.24 mg g−1, respectively. ANA 3 and ANA-MK 5 demonstrated…
Transition path selection between ammonium nitrate solid phases IV, III and II
1994
Article dissertation. Contains an introduction and five articles. This study was made of factors affecting the transition paths between ammonium nitrate solid state phases IV, III and II. The effect of the sample preparation method was investigated by differential scanning calorimetry (DSC), transition mechanisms were explored with simultaneous DSC and Raman spectrometry developed for in situ investigation of the transitions, and the relationship between phase IV structure and the transition paths was studies by X-ray powder diffraction (XRD) and DSC. The results were analysed by partial least-squares regression (PLS) and principal component analysis (PCA). [Continues; please see the book]
Landfill operation and waste management procedures in the reduction of methane and leachate pollutant emissions from municipal solid waste landfills
2002
The objective of the present research was to find ways of minimising emissions from municipal solid waste (MSW) landfills by means of laboratory experiments.
In-depth characterization of denitrifier communities across different soil ecosystems in the tundra
2022
Abstract Background In contrast to earlier assumptions, there is now mounting evidence for the role of tundra soils as important sources of the greenhouse gas nitrous oxide (N2O). However, the microorganisms involved in the cycling of N2O in this system remain largely uncharacterized. Since tundra soils are variable sources and sinks of N2O, we aimed at investigating differences in community structure across different soil ecosystems in the tundra. Results We analysed 1.4 Tb of metagenomic data from soils in northern Finland covering a range of ecosystems from dry upland soils to water-logged fens and obtained 796 manually binned and curated metagenome-assembled genomes (MAGs). We then sear…
Haitalliset kaasut työilmassa : kemialliset ominaisuudet ja määritysmenetelmät
2007
Typpiseostettu grafeeni
2017
Tässä Pro Gradu -tutkielmassa perehdytään typpiseostetun grafeenin rakenteeseen, ominaisuuksiin, karakterisointiin, valmistukseen ja sovelluksiin. Valtaosa typpiseostetun grafeenin ominaisuuksista pohjautuu puhtaaseen grafeeniin, joten myös sitä käsitellään samalla. Typpi voi sitoutua grafeenihilaan eri tavoilla, joten mahdolliset konfiguraatiot ja niiden vaikutus rakenteeseen ja grafeenin ominaisuuksiin käydään läpi. Spektroskopia ja karakterisointi -kappaleessa keskitytään eniten puhtaan ja typpiseostetun grafeenin ramanspektroskopiaan ja röntgensädefluoresenssispektroskopiaan (XPS). Valmistuskeinot-kappaleessa kerrotaan lyhyesti grafeenin yleisimmistä synteesimenetelmistä ja käydään läpi…