Academic literature on the topic 'Sodium Fluoride Solution'

This work presents a deep analyses of an environmentally friendly process to recover all valuable minerals contained in the spent potliner (SPL) such as graphite carbon and aluminum fluoride (AlF3) and production of sodium sulfate (Na2SO4) and gypsum (CaSO4) when H2SO4 is used as the leaching agent. The level of emission of hazardous gases such as HCN (weak acid) and HF are minimized by direct scrubbing of the HCN in aqueous AgNO3 solution to produce a stable silver cyanide (AgCN) product. The HF can be recovered as a liquid by condensation and used within the process and/or in production of metal fluorides such as the highly-soluble potassium fluoride (KF); a main source of fluoride in industry. Almost pure CO2 gas is also recovered from the process gas streams.

Interaction between nonionic organic contaminants (NOC) and natural organic matter strongly influences the fate and transport of NOC in the environment. Microscopic descriptions of NOC-organic matter interaction have been developed based on macroscopic observations of NOC sorption to organic matter and organic solute transport under varying conditions. These models include the partitioning concept describing NOC sorption to organic matter and the concept of intra-organic matter diffusion used to account for nonequilibrium organic solute transport; however, little microscopic information exists to validate them. NMR may be a powerful method to gain information and insight concerning NOC-organic matter interaction. Chemical shifts, linewidths, and the magnitude of spin-spin couplings exhibited in the NMR spectra of a given nucleus are dependent on the characteristics of the surrounding media and therefore can be used to study the NOC-organic matter interaction. NMR characterization of the chemical interaction between NOC and organic matter can potentially provide information on important aspects of the sorption mechanism. This information may be useful to explain the influence of organic matter characteristics on NOC sorption and the mechanisms controlling nonequilibrium sorption of NOC to organic matter and mineral phases, and to evaluate different conceptual models of natural humic material, including the polymer concept, where humics are considered to be flexible linear polyelectrolytes, and the micelle concept, which considers humics to be aggregates of simple organic compounds, oligomers, and humic molecules ultimately forming micellar-type structures. NMR has been used to study the interactions of small organic solutes with macromolecules and organized organic assemblies. Fluorine-19 NMR has been particularly useful to study these interactions because this magnetically active nucleus is 100% abundant, has a high sensitivity (83% of 1H) and large chemical shift range, and exhibits no background signal. Several NMR studies have followed the interactions between fluorinated anesthetics and phospholipids, sodium dodecyl sulfate (SDS) micelles, and intact rabbit brain tissue. Generally, these studies have indicated both that sorption sites are less polar than aqueous solutions and that there is decreased mobility of the sorbed solute. Fluorine-19 NMR has also been used to characterize the interactions between fluorine-containing ligands, such as fluorotryptophan, and human serum albumin (HSA).