Abstract: An electrochemical cell (60) and method for treating waste having an anode in the form of a number of elements comprising spheres (80) which locate between plates (78, 81). The spheres (80) divide the anode compartment (64) into parts (110, 111). The porous pot (62) separates the anode compartment from the cathode compartment (63). The electrode liquor is circulated over the elements from part (110) to part (111) by an impeller (86) located in a tube (75) having inlets (77) and outlets (76), the outlets (76) being at a different level from the inlets (77). A rake may stir the contents of chamber (111) particularly for solid waste. There may be a plurality of porous pots, each housing a cathode, in the anode compartment.

Abstract: A solvent extraction column in which a disperse phase in the form of electrostatically charged droplets contacts a fluid continuous phase. The disperse phase is received in a number of trays having radial nozzles, so that the disperse phase is discharged from the nozzles as charged droplets transverse to the general direction of flow in the column when an electric potential is applied between the trays and the column.