Abstract: A sling bar assembly allows variable positioning of a sling on the sling bar assembly. Some sling bar assemblies include opposing sling bar members that are movable with respect to one another in a lateral direction. Some opposing sling bar members are repositionable between a locked position, in which movement of the sling members with respect to one another is restricted, and an unlocked position. Some sling bar assemblies include multiple sling hooks positioned on a sling bar member. Some sling bar assemblies include a biasing member that permits movement of a sling hook with respect to the sling bar assembly in the lateral direction.

Abstract: An electrochemical cell (50) for deionizsation utilizes electrochemical ion-exchange to remove ions from a feed solution. Under the influence of an electric field, ions are adsorbed into, are scored within and pass through a permeable layer (54, 64) of particulate ion-absorbing material and binder, the sheet being several millimeters thick. Water from the feed solution also permeates through the layer (54, 64), so a concentrated solution of the ions emerges from the rear (58) of the layer. The cell does not require separate sources of feed and eluant solutions and can be operated substantially continuously. In a modified cell (70) the flow path for the feed solution passes through a highly porous ion exchanger structure (77), which may be located between two such microporous layers (54, 64). Absorption in such a cell may be effective in the absence of an electric field, elution requiring the periodic application of the electric field.

Abstract: Effluent streams from photographic processes contain both silver and thiosulphate ions, and because of the formation of complex anions it is difficult to remove the silver. The silver may be removed using a cell (12) with a cathode (24) exposed to the effluent liquid, and an anode (25) separated from the liquid by a barrier (22) permeable at least to anions. Some silver sulphide is formed electrochemically at the cathode (24); at the anode (25) water is electrolysed and becomes acidic, so the complex anions migrating through the barrier (22) generate silver sulphide chemically. The resulting silver sulphide precipitate is separated from the liquid by a filter (14).

Abstract: A filter (10) comprises a stack of flat rectangular filtrate-collecting chambers (12) defined by sheets (26) of stainless steel filter medium, and connected via respective thyristors (54, 58) to a power supply (50). Anode plates (14) are arranged between adjacent chambers (12). At intervals a current (of for example 1000A) is supplied to each chamber (12) in turn such that it is a cathode, for a short time sufficient to remove any fouling.

Abstract: An electrode for use in electrochemical ion exchange comprises an electrically conducting element covered by at least two layers of ion exchange material. The material in one layer differs in its electrical, chemical, or ion exchange properties from that in an adjacent layer. For example a thin layer of cation exchange material underneath a thicker layer of anion exchange material may be used to inhibit the oxidation of chloride ions; a thin layer of cation exchange material covering a thicker layer of anion exchange material provides an anion-responsive electrode with enhanced selectivity for particular ions. An ion-selective anion-responsive electrode can also comprise a thin outer layer of a very weak base anion-responsive material, covering a thicker layer of a strong base material of lower electrical resistivity.

Abstract: An apparatus for treating a liquid by electrochemical ion exchange comprises a flow channel (34) in which are arranged a cation-responsive ion exchange electrode (38) side by side with an anion-responsive ion exchange electrode (42), with a counter electrode (40,44) between them. By controlling the currents to the two ion exchange electrodes (38,42) independently, the pH of the treated liquid can be controlled at a desired value.

Abstract: A first metal, for example a transition metal such as cobalt, having an insoluble hydroxide is separated from a second metal such as lithium having a soluble hydroxide in an aqueous liquid containing dissolved cations of the metals. The cations are firstly absorbed onto a cation exchange material by electrochemical ion exchange and the second metal then selectively eluted by electrochemical ion exchange under sufficiently high pH conditions, e.g. to 10-13, in a closed loop. Finally, the transition metal is eluted by electrochemical ion exchange under sufficiently low pH conditions, e.g. acidic such as 1-2. The method is applicable to separating trace quantities of Co (e.g. as Co-60) from larger quantities of Li in aqueous solution.

Abstract: An electrode used in electrochemical deionization comprises a current feeder disposed asymmetrically in an ion exchange material bonded into a coherant structure i.e. more of the ion exchange material adheres to one side of the current feeder than to the other side. The ion exchange material may be bonded by being provided in intimate admixture with a binder. Such an electrode offers manufacturing ease and the ability to be scaled up in multi-modular form.

Abstract: Ruthenium in aqueous solution in a first, oxidizable oxidation state (e.g. as RuNO(NO.sub.3).sub.3) is converted to an insoluble form in a second, different oxidation state (e.g. as RuO.sub.2.nH.sub.2 O) by establishing an electrochemical cell wherein the solution is the electrolyte and electrochemically oxidizing and reducing the ruthenium in the cell. The insoluble form may be filtered from the liquid. The ruthenium treatment may be a stage in the removal of radioactive species from liquids such is in the treatment of medium and low level activity liquid waste streams, wherein actinides are precipitated and filtered off either before or after ruthenium treatment. Subsequently, residual activity may be removed from the stream by either or both of (a) absorption, followed by filtration and electro-osmotic dewatering and (b) electrochemical ion exchange. Filtration fluxes may be maintained by direct electrochemical membrane cleaning.

Abstract: Ions are electrochemically removed from an aqueous solution by establishing an electrochemical cell wherein the solution, as cell electrolyte, is caused to flow between a working electrode that includes an ion exchange material and a second electrode that optionally includes an ion exchange material. The polarity of the cell is repeatedly reversed so that ions are successively adsorbed and desorbed at the working electrode and optionally also at the second electrode. Thus, an ion for removal such as Cs.sup.+ may be selectively removed in the presence of a much larger concentration of a second ion such as Na.sup.+.

Abstract: An electrochemical cell, e.g. a lead acid electric storage cell, comprises a positive electrode, a negative electrode, an aqueous electrolyte and, optionally, a porous cell component such as a cell separator interposed between the electrodes. To enhance access of electrolytes to one or both of the electrodes or to the component during operation of the cell and thereby improve cell performance, at least one of the component and the electrodes is porous and includes a promoter in the form of solid material other than graphite having, under the operating conditions of the cell, a zeta potential of such magnitude and polarity as to be capable of inducing electro-osmotic flow of electrolyte into the component or electrode when a current is flowing through electrolyte filled pores thereof. An example of such a material (termed an `electro-osmosis promoter`) is sulphonated polyvinylidene difluoride.

Abstract: A porous electrically conducting filter, e.g. a membrane for filtration equipment, is cleaned by setting up an electrochemical cell comprising the membrane as a first electrode (usually the cathode), a second electrode, and an electrolyte capable of being electrolyzed to a gaseous product at the first electrode. When a potential is applied across the cell, the gaseous product of electrolysis (e.g. in the form of microbubbles) cleans the surfaces of the membrane by forcing foulant material therefrom.The electrolyte is constituted by the liquid being filtered (with the possible addition of a salt to increase electrical conductivity, if necessary) thus enabling filter cleaning to be carried out in situ while the liquid being filtered continues to be passed through the filter.

Abstract: An electrochemical extraction method comprises establishing a cell of the form working electrode: flowing aqueous electrolyte solution: second electrode. The working electrode includes an ion exchange material and the second electrode may include ion exchange material. D.C. potential is applied to the cell to adsorb ions onto the working electrode and cell polarity is subsequently reversed to elute the adsorbed ions.The cell is separated by a cell divider, e.g. in the form of an ion selective membrane, into first and second electrolyte compartments and the solution is passed through the compartment adjacent the working electrode to effect adsorption and, where the second electrode includes ion exchange material, solution is passed through the compartment adjacent the second electrode to effect desorption.

Abstract: An electrode for use in electrochemical deionization comprises a current feeder support carrying an intimate mixture of an ion exchange material, and a binder.The electrode is provided with an inert, electrolyte-permeable outer envelope, adhered to the mixture, for maintaining the mixture in contact with the current feeder during use of the electrode in electrochemical ion exchange. The envelope may be in the form of a non-woven polyamide cloth and may be provided with an outer restrainer, e.g. in the form of a metal or plastics mesh.