Proposed Separation Method Research Articles

Production of source-separated domestic waste fractions

The separation of domestic waste materials at source of production is a well-known method which has gained renewed interest in recent years. Projects which have been concluded in the Netherlands, and those still in progress, such as those running at Groningen, Den Bosch, Amersfoort and Woerden, are to be described. The results already available with respect to collectson of domestic refuse and its separation into fractions are also presented. In addition, an indication is given of where outlet markets may be found for these fractions. The research carried out so far has led to the following conclusions: (1) The population can be sufficiently motivated to separate domestic refuse at the source; (2) Subsequent separation into secondary raw materials is technically feasible; (3) A scaling-up process is required to assess the economic feasibility of the proposed separation method.

Statistics of photodeflection

Abstract We consider random fluctuations in the velocity of a molecule which is subjeclted to laser radiation. Three cases are treated, each applicable to a proposed method of isotope separation. In the first case, an exact solution is found for the velocity distribution using combinatorial methods. In the second and third cases. approximate solutions are obtained.

A proposed method of hydrogen isotope separation using palladium alloy membranes

The viability of using palladium alloy membranes in cascade to separate the hydrogen, deuterium and tritium produced in a fusion reactor is discussed. Values of the permeation separation factor are estimated for Pd-20%Ag from available data and corresponding estimates for the necessary number of stages and the total membrane area are given for the required isotopic purification. The results demonstrate the advantage of minimizing the operating temperatures and pressures and indicate that the method is perfectly feasible. The use of Pd-8%Y will probably even further improve the performance.

Possibility of the optical separation of the isomeric nuclei by laser radiation

The possibility of using laser radiation for fast optical separation of isomeric nuclei is considered. The proposed method of separation is based on selective two-step photoionization of atoms or photodissociation of molecules.

Separation of rhodium from iridium with sodium borohydride and standardization of rhodium(III) solutions

Of the platinum group metal separations, that of rhodium from iridium is the most difficult. The existing gravimetric methods are too lengthy or make use of organic reagents which ultimately need to be removed before iridium can be determined. The proposed method of separation is rapid, needs no pH control, and easy to carry out. Rh(III) ions are quantitatively reduced to Rh(0) by the action of aqueous sodium borohydride. The separation is best achieved in perchlorate medium in the presence of hydroxylamine. The separation is dependent on the concentration ratio of iridium to rhodium; if this is high, some iridium is co-precipitated; if low, the rhodium obtained is free from even spectrographic traces of iridium. A new method for standardization of Rh(III) solutions with sodium borohydride is proposed.

An Observation of a Field-Flow Fractionation Effect with Polystyrene Samples

Abstract Field-flow fractionation (FFF) is a proposed separation method in which some kind of lateral field is coupled with nonuniform axial flow to induce differential migration (1). Fractionation is here illustrated by applying a temperature drop laterally across a narrow tube within which a mixture is flowing. In this case thermal diffusion is responsible for lateral enrichment. This variation of the general concept may be termed thermal field-flow fractionation.