A continuous process for treating a fertilizer plant waste aqueous stream containing ammonium, hardness metal and nitrate values to recover an ammonium nitrate fertilizer and a demineralized and substantially nitrate-free aqueous stream for recycle includes initially removing the ammonium ion and hardness metal ion values from the fertilizer plant waste aqueous stream with a cation exchange resin bed and then contacting the essentially ammonium and hardness metal ion-free aqueous stream with an anion exchange resin bed to recover a second ammonium nitrate fertilizer stream and a demineralized and nitrate-free aqueous stream.

Process for treating fertilizer plant waste streams

A method for generating softened injection water (A) (i) introducing source water having a dissolved solids content of up to 15,000 mg/liter and a multivalent cation content of greater than 40 mg/liter to a bed of cation exchange resin in monovalent cation form, (ii) passing the water through the bed so that at least a portion of the multivalent cations in the water are replaced by monovalent cations from the resin, and (iii) withdrawing the softened injection water having a multivalent cation content of up to 40 mg/liter; (B) regenerating the cation exchange resin by (i) introducing a regenerating brine to the vessel, (ii) passing the brine through the bed and (iii) withdrawing a brine containing displaced multivalent cations, wherein the brine is a naturally occurring high salinity water having a concentration of cations such that the Softening Limit for the source water is up to 40 mg/liter of multivalent cations

Method for generating softened injection water

A process for continuous countercurrent ion exchange comprises piping a contaminated feed stream into a closed loop ion exchange contactor. The contactor is an ion exchange bed that has three or more reaction segments. The segments are comprised of at least an adsorption segment for treating the contaminated feed stream, a regeneration segment for stripping the contaminant ions from the resin bed, and a pulse segment for advancing the resin bed. Simultaneously, the feed stream is moved through the contactor in the same direction as the regeneration stream. Measuring the quality of this treated feed stream after it exits the contactor monitors the treatment capacity of the resin bed. In response to this quality measurement, the regenerated resin bed is advanced in the pulse segment of the contactor. The spent brine is recycled back to the contactor until the final effluent brine is highly concentrated. After the resin stops advancing, the feed stream and regeneration stream resume flow. Process water is recycled in four different steps of the ion exchange process, for the dilution of acid, as resin rinsing water, for back wash and during the resin pulsing stage.

Process for continuous ion exchange

A loop-style continuous ion exchange unit having a liquid treating section, a material weighing and transfer section, a regeneration section, a washing section and a back-washing section, all of which are connected together in a closed loop. The back-washing section is above the liquid treating section to enable material to fall by gravity into the liquid treating section. The liquid treating section is located above the material weighing and transfer section so that material can fall by gravity into the material weighing and transfer section. The washing area has an outlet located above the back-washing area so that washed material may flow by gravity to the back-washing area. Further, an expansion space is provided above the washing area to compensate for expansion of the material when it is washed.

Loop-style continuous ion exchange unit

A process for the removal of thermally-stable contaminants from stack gas scrubbing amines using a continuous countercurrent ion exchange column. Amines contaminated after use in stack gas scrubbing are fed into the column containing an anion exchanger resin where the contaminants are sorbed on the resin. The amine is washed from the resin with hot water and is removed from the column. The resin is then pulsed to move the resin with the sorbed contaminants into a elution section of the column. The contaminants are removed using an eluant of sodium hydroxide solution, preferably containing chlorine to enhance elution of thiocyanate ion. A water wash removes traces of the hydroxide solution and any reaction products, and then the resin is again pulsed so as to be moved for reuse. The amines are regenerated with only the single type resin (preferably Type I) and with significantly reduced quantity of reagents.

Extraction of thermally stable contaminants from stack gas scrubbing amines

A CONTINUOUS CYCLIC PROCESS FOR COUNTERCURRENT CONTACT OF A CONTAMINANT CONTAINING LIQUID WITH A SOLID IN A COLUMN LOOP WHICH INCLUDES INTRODUCING THE CONTAMINANT CONTAINING LIQUID INTO THE UPPER PORTION OF ONE SECTION OF THE COLUMN LOOP FOR DOWNWARD FLOW THROUGH THE SOLIDS BED THEREIN TO TRANSFER OR LOAD THE CONTAMINANT ONTO THE SOLIDS. THE SECTION IS POSITIONED ADJACENT THE UPPER END OF THE COLUMN LOOP. LIQUID WITH A REDUCED AMOUNT OF CONTAMINANT IS WITHDRAWN FROM THE LOWER PORTION OF THIS SECTION. A REGENERATING AGENT IS FED TO THE LOWER PORTION OF ANOTHER SECTION OF THE COLUMN LOOP FOR FLOW THROUGH A BED OF SOLIDS LOADED WITH THE CONTAMINANT. THE FLOW OF LIQUID AND REGENERATING AGENT ARE INTERRUPTED AND THE SOLIDS BED IS SHIFTED AROUND THE LOOP AND THE LOADING AND REGENERATING CYCLES ARE THEN REPEATED.

Irwin Raymond Higgins

Papers

Downflow ion exchange