High efficiency ion exchange system for removing chromium VI contaminants from water

A system for continuously removing chromium VI contaminant from chromium VI contaminated water comprising:

• a plurality of immobile vessels, each containing a resin bed capable of binding chromium VI contaminant from said chromium VI contaminated water and yielding purified water and a chromium VI contaminated resin bed;
• a plurality of electronically controlled valves fitted to each one of the immobile vessels, one of said valves admitting contaminated water to the vessel, one removing purified water, one admitting regenerant, one admitting rinse liquid and one or more removing regenerant rinse liquid;
• and
• an electrical controller directing the plurality of electrically controlled valves so that when the system is in operation continuously removing chromium VI contaminant, chromium VI contaminated water is flowed to a subset of vessels, regenerant is flowed to a subset of vessels containing the most highly chromium VI contaminated resin bed and rinse liquid is flowed to a subset of containing the least contaminated resin bed.

A process for continuously removing chromium VI ion contaminant from chromium VI ion-contaminated water comprising:

• with a controller, feeding said contaminated water through a first manifold to individually-valved first headers each directly adjacent to a first opening into each of a first subset of a plurality of immobile vessels, each containing between said first opening and a second opening an ion exchange resin bed capable of binding chromium VI contaminant from the contaminated water and yielding reduced chromium VI level water and a chromium VI-contaminated resin bed,
• with a controller, removing reduced chromium VI level water through the second opening from each of the vessels in the first subset, and passing said reduced chromium VI level water through a second individually-valved header directly adjacent to the second opening and through a second manifold to a reduced chromium VI level water discharge;
• with a controller, feeding regenerant solution to an individually-valved header directly adjacent to a first or second opening on one or more additional vessels making up a second subset of the plurality each such vessel containing a chromium VI-contaminated resin bed,
• with a controller, passing the regenerant solution over the chromium VI-contaminated resin bed so that the regenerant displaces the chromium VI contaminants off of the chromium VI-contaminated resin bed to yield a regenerated resin bed and spent regenerant solution which is removed from the other opening on the vessel and through another individually-valved header directly adjacent to this opening,
• with a controller, feeding rinse water to an individually-valved header directly adjacent to a first or second opening on one or more additional vessels making up a third subset of the plurality each such vessel containing a regenerated resin bed, and
• with a controller, passing the rinse water over the regenerated resin bed to yield a rinsed, regenerated resin bed and used rinse water which is removed from the other opening on the vessel and through the individually-valved header directly adjacent to this opening.

A process for continuously removing chromium VI contaminant from nitrate-contaminated water comprising:

• a) with a controller continuously feeding nitrate contaminated water through a first manifold to individually-valved first headers each directly adjacent to a first opening into each of a first subset of a plurality of immobile vessels, each containing between said first opening and a second opening an ion exchange resin bed capable of binding nitrate contaminant from the nitrate contaminated water and yielding reduced nitrate level water and a nitrate contaminated resin bed, the vessels in said first subset having been in service for varying periods of time and thus having varying degrees of nitrate contamination of their resin beds,
• b) with a controller continuously removing reduced nitrate level water through the second opening from each of the vessels in the first subset, and passing said reduced nitrate level water through a second individually-valved header directly adjacent to the second opening and through a second manifold to a reduced nitrate level water discharge,
• c) with a controller periodically halting the feeding of step a) and the removing of step b) to and from the vessel in the first subset of vessels having the most highly nitrate contaminated resin bed thereby withdrawing that vessel from purification service,
• d) with a controller feeding regenerant solution to an individually-valved header directly adjacent to an opening on the vessel withdrawn from service in step c) and passing the regenerant solution over the nitrate-contaminated resin bed so that the regenerant displaces the nitrate contaminants off of the nitrate-contaminated resin-bed to yield a regenerated resin bed and spent regenerant solution,
• e) with a controller removing spent regenerant solution from another opening on the vessel and through an individually-valved header directly adjacent to this opening,
• f) with a controller halting the feeding of step d) and the removing of step e) once a desired degree of regeneration has been attained thereby withdrawing that vessel from regeneration service,
• g) with a controller feeding rinse water solution to an individually-valved header directly adjacent to an opening on the vessel withdrawn from service in step f) and passing the rinse water over the regenerated resin bed so that the rinse water displaces regenerant solution from the regenerated resin bed to yield a rinsed regenerated resin bed and used rinse water,
• h) with a controller removing used rinse water from another opening on the vessel and through an individually-valved header directly adjacent to this opening, and
• i) with a controller halting the feeding of step g) and the removing of step h) once a desired degree of rinsing has been attained.