Abstract: A method is provided for the electrokinetic decontamination of land or other material comprising soil in which a direct current is applied between at least one cathode (2) and at least one anode (4) positioned in or on said soil. The anode (4) is a carbon felt wrapped around current (10) and electrolyte feeders and the cathode (2) is contained in a porous housing (6) through which electrolyte is able to pass. On application of current there is electrokinetic movement of cations and other soil contaminants towards the cathode which pass through the porous housing and into the catholyte. The thus loaded catholyte is circulated through a treatment plant.

Abstract: An electrochemical cell is provided for removal of metals such as copper, lead, silver, tellurium, platinum, palladium or nickel from dilute solutions of the metal. The cell comprises a porous tubular support (18) which is provided with a cathode comprising a porous carbon fiber material (19), a current feeder (15) for the cathode, a tubular anode (12) spaced from said cathode, a current feeder (16) for the anode, the anode and the cathode being enclosed by a non-porous outer casing (11). In use the dilute solution from which the metal is to be removed is introduced into the cell through an inlet (13) and flows through the porous carbon fiber cathode to an outlet (14). The cell is useful for removing harmful metals from wastes so that they are environmentally acceptable for disposal and for recovery of valuable metals.

Abstract: An induction heater is provided which has an electrical conductor (40) extending along an axis B. At least one solid heating element (43) for contacting and transferring heat to a material to be heated extends radially from the axis B and is formed of electrically conductive and preferably ferromagnetic material. An alternating electric current is supplied to the electrical conductor (40) to induce an electric current in a closed loop defined by a surface layer of the or each heating element (43) to generate heat therein. Induced eddy currents are confined to a surface layer due to the skin effect. The radial and axial thickness of the heating elements (43) is greater than twice the skin depth of the electrically conductive material at the frequency of the alternating electric current. Preferably the heating element (43) is in the form of a screw arranged on an electrically conductive heating member (42).