However, deionization and demineralization may be accomplished by technologies other than ion exchange (see reverse osmosis ).
For systems requiring very low levels of residual CO2, a vacuum degassifier is used.
The regenerant levels and the feed water composition will then define the resin operating capacity.
Resin is regenerated on site using hydrochloric or sulfuric acid and sodium hydroxide (caustic) to regenerate the cation and anion respectively.This reduces the CO2 to below 1 mg/L.Alternatively, the resin may be furnished in echange permis conduire etranger rhone vessels by the WaterProfessionals and regenerated off site, with the many advantages shown under deionization.With sulfuric acid regeneration, two separate cation columns should be used in order to allow acid dilution at the weak acid resin inlet.The following general guidelines are given to help in configuration and resin selection.Ion exchange is a process used extensively in nuclear facilities, industrial processes and medical and pharmaceutical operations to control the purity and pH of water by removing undesirable ions and replacing them with acceptable ones.This configuration has advantages in terms of regeneration efficiency and operating capacity.Regeneration, the "reactivation" process is called regeneration and is carried out using a strong acid for the cation (as a source of hydronium ions) and liquid caustic (sodium hydroxide) as a source of hydroxyl ions for the anion.Specifically, it is the exchange of ions between a solid substance (called a resin) and an aqueous solution, typically municipal, potable water but it frequently involves process or even waste water (e.g., the plating industry).
For separated anions, dowex marathon WBA and dowex marathon A resins are recommended.
Selection of Resin Types: Strong Acid Cation Resin, strong Acid Cation Resin is used for water softening in the Na cycle and for demineralization when the temporary hardness in the feed.
Weak Acid Cation Resin, weak Acid Cation Resin is used as a single resin for dealkalization in the H cycle and for brackish water softening in Na cycle.
In demineralization, the use of a weak acid cation in front of a strong cation is preferred with feed waters containing a high proportion of temporary hardness ( 40) and low FMA.
Step 2: Selection of Layout and Resin Types (Configuration).
With large plants ( 400 m3/hr or 1800 gpm however, it may be more appropriate to have 3 lines (2 x 50 in parallel, 1 in standby) in order to reduce system redundancy, optimize flow conditions and reduce vessel sizing.
Such quality will also be even more affected by the water composition, the type of regenerant chemical and dosage being used.In the case of mixed bed resin, a controlled backwash causes the resin to separate and two manifolds function to direct acid to the cation and caustic to the anion.Amaira Umer Joins Purolite Life Science as Quality Associate.This arrangement is called a mixed-bed resin, as opposed to an arrangement of cation and anion resins in discrete layers or separate vessels.Step 8: Mixed Bed Design Considerations A polishing mixed-bed will be required if the product water specification is below that achievable from the demineralization plant alone or if a higher degree of safety is required to ensure water quality.To avoid disturbance of the resin polishing zone at the bottom of the vessel, the resin bed is held down (blocked) during regeneration by air pressure, water flow or an inert mass in the top part of the vessel.The plant configuration will depend on the feed water composition, the water quality required and the economics of operation.HCl is a trouble-free regenerant with high efficiency.These Brochures provide complete engineering information for individual dowex resins, including operating capacity and leakage curves as well as backwash and pressure drop data.Chemically, both types are similar and belong to a group of compounds called polymers, which are extremely large molecules that are formed by the combination of many molecules of one or two compounds in a repeating structure that produces long chains.US Power Plant Water Treatment Conference.Common cations include Ca2, Mg2, Fe2, and.In order to compensate for non-ideal operating conditions and resin aging on a working plant, it is recommended to apply a safety factor to operating capacity figures.