Abstract: Methods for improving ion flux and energy efficiency in a membrane stack of an electrodialysis unit wherein the membrane stack is disposed between an anode and a cathode each in an electrolyte of a selected concentration. Methods include increasing the concentration of the electrolyte, adding a strong base to the electrolyte and adding buffering anions to the electrolyte. Methods for cleaning the electrodes of such a unit involving involve applying a pulsed polarity reversal to the electrodes. Also provided are methods for improving unit operation by increasing the basicity of the electrolyte to the anode and increasing the acidity of the electrolyte to the cathode or alternatively or in addition, by applying heat to increase the operating temperature of at least one of the electrolyte and the treated water stream.

Abstract: Methods for controlling electrolyte chemistry in electrodialysis units having an anode and a cathode each in an electrolyte of a selected concentration and a membrane stack disposed therebetween. The membrane stack includes pairs of cationic selective and anionic membranes to segregate increasingly dilute salts streams from concentrated salts stream. Electrolyte chemistry control is via use of at least one of following techniques: a single calcium exclusionary cationic selective membrane at a cathode cell boundary, an exclusionary membrane configured as a hydraulically isolated scavenger cell, a multivalent scavenger co-electrolyte and combinations thereof.

Abstract: Methods for improving ion flux and energy efficiency in a membrane stack of an electrodialysis unit wherein the membrane stack is disposed between an anode and a cathode each in an electrolyte of a selected concentration. Methods include increasing the concentration of the electrolyte, adding a strong base to the electrolyte and adding buffering anions to the electrolyte. Methods for cleaning the electrodes of such a unit involving involve applying a pulsed polarity reversal to the electrodes. Also provided are methods for improving unit operation by increasing the basicity of the electrolyte to the anode and increasing the acidity of the electrolyte to the cathode or alternatively or in addition, by applying heat to increase the operating temperature of at least one of the electrolyte and the treated water stream.

Abstract: Methods for controlling electrolyte chemistry in electrodialysis units having an anode and a cathode each in an electrolyte of a selected concentration and a membrane stack disposed therebetween. The membrane stack includes pairs of cationic selective and anionic membranes to segregate increasingly dilute salts streams from concentrated salts stream. Electrolyte chemistry control is via use of at least one of following techniques: a single calcium exclusionary cationic selective membrane at a cathode cell boundary, an exclusionary membrane configured as a hydraulically isolated scavenger cell, a multivalent scavenger co-electrolyte and combinations thereof.

Abstract: A method of extracting oil-soluble contaminants from soils, sediments, or porous solids is disclosed. In one embodiment, the method comprises the steps of immersing the solid in a fluid comprising a water phase and an oil phase, mixing the phases and allowing the phases to separate, wherein the contaminants are thereby concentrated in the oil phase.

Abstract: A method and apparatus (10) for separating materials having different size densities is described. The apparatus includes a trough (12), a dispersing and conveying screw means (40) and a fluid distribution manifold (26). The trough has upper and lower portions (12F and 12G) with the lower portion forming a pool area. The dispersing and conveying screw means has a conveying portion (46) and a dispersing portion (50). The conveying portion has flights (48) which move the first material (152) up the trough. The dispersing portion has paddles (52) which disperse the mixture (150) and convey the first material to the conveying portion. The fluid distribution manifold supplies both water and air to the inside (12I) of the trough through fluid orifices (28). In operation, the mixture is fed into the trough directly over the fluid orifices and the dispersing portion of the dispersing and conveying screw means. As the mixture enters the trough, the mixture is dispersed and forms an aqueous suspension with the water.

Abstract: A method and apparatus for the separation of manure (104) and sand (102) in a sand and manure mixture (100) is described. The apparatus (10) of the first embodiment includes a tank (12) with an upper grate (22), a lower grate (20), an air supply tube (30) and a water supply tube (36). The apparatus (210) of the second embodiment includes a tank (212) having a screened grate (220), an air supply tube (230) and a water supply tube (236). The apparatus (310) of the third embodiment includes a tank (312) having an upper portion (312C) and a conical lower portion (312D) with a grate (320) between the two portions. In operation, all three embodiments essentially operate similarly. The chamber (12F, 212F and 312F) of the tank is filled with water. The mixture is then dumped into the chamber to form the aqueous suspension (106) with the water.

Abstract: An apparatus for simulating the operation of a full-scale belt filter press consists of a support base, a filter belt and a press belt each anchored at one end to the support base and passing over a static curved pressure face and a winch for exerting a pulling force on the press belt against the static curved press face to remove water from a sample of slurry on or within the belts. An improvement in the method of removing liquid from a slurry with a belt filter press also is disclosed which consists of pulling the pair of belts containing a slurry against a static curved pressure face to force liquid out of the slurry.