The interphase distribution of light REE Ce(III) and La(III) in system based on PEG-1500 – NaNO3 – H2O with the quaternary ammonium base addition

The problem of e-waste processing and recovery of valuable metals from such waste for the second use is attracting more and more scientists’ attention. Liquid extraction as one of hydrometallurgy steps is a traditional method for the metal recovery. However, application of solvent extraction is not meet the green chemistry principles due to organic solvents. Aqueous two-phase systems based on water-soluble polymers are promising alternative for hazardous organic solvents. In this work the dependencies of Ce(III) and La(III) distribution coefficients from process time and the initial quaternary ammonium base concentration have been achieved. Also, based on the Ce(III) and La(III) extraction isotherms it has been shown that the metals initial concentrations are highly affects the distribution coefficients of studied metals. The possibility of aqueous two-phase system application as a solvent for quaternary ammonium salt for light REE (Ce(III) and La(III)) extraction from water solution has been shown.

Preparation and catalytic performance of quaternary ammonium base resin for methanolysis of natural phosphatidylcholine

Received 1 August 2015; Revised 23 November 2015; Accepted 26 November 2015The most acceptable method for preparing glycerophosphocholine is to hydrolyse the natural phosphatidylcholine and use the quaternary ammonium base resin, as a promising heterogeneous catalyst can simplify the craft and minimise the problems existing in the homogeneous catalytic process. However, most of the resins reported in the literature are commercial trimethyl benzyl ammonium base resins and the application of other longer carbon-chain quaternary ammonium resins has not been reported. In the present work, a series of quaternary ammonium base resins were prepared from chloromethyl polystyrene microspheres and different tertiary amines and were used to prepare glycerophosphocholine from natural phosphatidylcholine. The factors affecting the exchange capacity and activity of the resin were investigated. The results showed that the resin possessed a better activity and stability under the following conditions: 1,4-dioxane as solvent, triethylamine as amination agent, reaction temperature of 60°C and amination time of 3 h; it was then used in the methanolysis of phosphatidylcholine by ultrasound-assisted reaction at ambient temperature, with the conversion of phosphatidylcholine attaining 97 % after 4 h. The catalyst was easy to separate from the reaction mixture and could also be readily available for repeat use; the activity and stability were largely consistent after six repeat uses.