Abstract: The present description relates to a method and a system for generating a Fenton reagent. Particularly, the description relates to a method and a system for oxidizing contaminants from wastewater. The Fenton reagent can react with various organic compounds and metallic elements. The method of producing an in-situ Fenton reagent comprises: providing an aqueous solution comprising at least one contaminant; providing at least one column comprising i) an inlet and an outlet separated by a flow chamber, and ii) a mass of iron fibre in the flow chamber between the inlet and the outlet; providing at least one dispenser retaining a hydrogen peroxide generating solid and permitting passage of the aqueous solution through the dispenser; optionally acidifying the solution upstream of the at least one column, and passing the aqueous solution through the at least one column.

Abstract: The present invention relates to method and a system of reducing chromium (VI) from a chromium bearing solution. The reduction of the chromium (VI) is achieved by contacting the chromium bearing solution which comprises chromium (VI) ions in an aqueous solution with iron fibers in an exchange mass under oxidation-reduction potential conditions at a pH of at least 2.5, with entry of iron ions into solution in the aqueous solution and reduction of the chromium (VI) ions to chromium (III) recovered in the exchange mass. A solution substantially free of chromium (VI) ions and total chromium is produced and discharged from the exchange mass.

Abstract: The present describes a method and system for controlling conductivity of fountain solution during printing.

Abstract: Silver recovery from a silver-bearing spent photographic solution is achieved by reducing the silver ions to silver metal with an organic reducing agent, especially a photographic developer reagent; in particular a spent photographic developer solution provides a convenient source of reducing agent for the silver recovery; in this case the developer reagents which typically are phenol-type compounds are oxidized leading to a less toxic discharge effluent having a lower COD and BOD.

Abstract: Spent color photography liquids comprising alkaline developer liquid and fixer liquid loaded with iron ions generate a dischargeable effluent, in which clogging of drains and conduits with precipitated iron oxides is minimized or avoided; the liquids are fed through separate feed ports into a vessel to form a liquid bath, the feed ports being isolated from each other and from the liquid bath; liquid effluent is pumped from the bath to form an effluent flow; preferably the pumping employs a suction generated by flow of a carrier liquid such as water through a venturi passage, whereby the liquid effluent is entrained in the flowing water and discharged under pressure, the precipitated iron oxides being retained in a dispersed non-clogging state.

Abstract: Value metal, for example, silver in a spent silver bearing photographic solution is efficiently recovered in an exchange mass comprising a particulate inert substrate, for example, cellulosic fibers, synthetic fibers or sponge particles, co-mingled and interlocking with elongate particles of replacement metal, for example, strands of steel wool; the substrate defines a non-channeling random flow paths for liquid flow, and inhibits carriage of recovered value metal by the flowing liquid.

Abstract: The container is made of a single blow molded piece having a pair of vertical column chambers, inlet and outlet connectors and tubes connecting the inlet and outlet connectors to circulate fluid through the vertical column chambers in series. Each container is filled with a recyclable filter medium and the container can be recycled with the filter medium. When the filter container is replaced, the entire filter container is sent for recycling. The filter container can be attached to other filter containers to form a compact filter assembly or the container can be mounted to a wall to be stored out of the way. When the containers are connected together, they can be arranged to be easily connected in series and when replacing spent filter containers, it is possible to replace only some of the containers connected in series to leave partially spent containers in the fluid circuit for further use while new containers are added to an outlet side of the containers connected in series.

Abstract: A neutral dischargeable effluent is developed by reaction between an acidic, spent photographic fixer liquid and an alkaline, spent photographic developer liquid; the spent fixer liquid contains iron in solution, the iron being introduced in a de-silvering pretreatment of the spent fixer liquid. The two liquids are fed into a treatment chamber and are allowed to react in the treatment chamber to form a neutral liquid and precipitated iron-containing solids; the solids settle in the treatment chamber and the neutral liquid rises upwardly through a synthetic organic polymer fiber filter pad into a discharge chamber above the filter pad; fine sticky particles suspended in the rising neutral liquid are retained by the filter pad; a neutral effluent is discharged from the discharge chamber.

Abstract: The cell controller 18 responds to a number of specific conditions including a flow switch 24 output signal 34 which indicates that fresh solution flows from a reservoir 14 into the metal solution tank 12. The cell will be caused to operate in the plating mode in response to the detection of fresh solution flow, and cell performance can be monitored by comparing an estimate of metal released into the solution based on flow of fresh solution and a measurement of metal recovered. The invention is particularly advantageous for controlling the electrolytic recovery of silver from photographic processing solution.

Abstract: In the recovery of an electrically conductive metal from a liquid containing the metal in solution, a cathode member for deposition of the metal by electrolysis, comprises a carrier sheet with a cathode element of the metal to be recovered, on one side of the sheet; the carrier sheet is of a material from which the metal is readily refinable when smelted with the carrier sheet; the cathode member has particular application for removal of the silver content of fixer solution in photography; suitably the sheet is flexible and has a memory of a planar state, such that on being rolled into a cylindrical tubular configuration, it returns to the planar state unless restrained.

Abstract: The system is operable in either a standby mode, having associated with it a predetermined standby current level, or a plating mode, having associated with it a predetermined plating current level. The system also has associated with it a cut-off current level at which the system is transferred from the plating mode to the standby mode, and a come-on current level at which the system is transferred from the standby mode to the plating mode. A variable voltage generator impresses a voltage across the electrolytic solution, and this voltage is monitored by a microcontroller. The voltage for each mode is the voltage which will produce the predetermined current for that mode. When the microcontroller determines that the voltage has remained stable, that is, with a deviation less than .+-.5% for a predetermined period of one minute, then the microcontroller will provide a signal to the voltage generator to initiate a change of mode.